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This study shows that in the potash flotation system, in which long-chain amine collector appears in the form of colloidal particles, the hydrophobicity of sylvite surfaces critically depends on whether the amine is placed onto the solid surface or onto the surface of a bubble. The transportation of amine collector on the surface of bubbles was found to be beneficial for the bubble/KCl particle attachment.

This study elucidates the behaviour of heavy metals in slag produced from four different sewage sludge ashes mixed with municipal solid waste incinerator fly ash and then co-melted. Experimental results indicate that sewage sludge ashes consisted of SiO 2, CaO, and Al2O3. Fly ash consisted of CaO, Na2O and SO3. The speciation of sewage sludge ashes indicates that the ashes contained quartz and AlPO4. The speciation in fly ash consisted of anhydrite, microcline, calcium chloride, sylvite and halite. The leaching behaviours of sewage sludge ashes met the Taiwan Environmental Protection Administration’s regulatory standards. The fly ash had high concentrations of Zn and Pb; however, the leaching of these metals was low. The major components of synthetic slags were SiO2 (33.5—54.0%), CaO (21.4—36.7%), and Al2O3 (8.1—15.7%). The X-ray diffraction patterns of co-melted slags demonstrate that the slags contained significant amounts of glass. Most heavy metals can be fixed in a net-like structure; thus, they can not be extracted easily. The toxicity characteristic leaching procedure (TCLP) leaching concentrations for target metals in all slags met the Taiwan Environmental Protection Administration’s regulatory standards.

Abramovite, a new mineral species, has been found as fumarole crust on the Kudryavy volcano, Iturup Island, Kuriles, Russia. The mineral is associated with pyrrhotite, pyrite, wurtzite, galena, halite, sylvite, and anhydrite. Abramovite occurs as tiny elongated lamellar crystals up to 1 mm long and 0.2 mm wide (average 300 × 50 μ m), which make up chaotic intergrowths in the narrow zone of fumarole crust formed at ∼600°C. Most crystals are slightly striated along the elongation. The new mineral is silver gray, with a metallic luster and black streak. Under reflected light, abramovite is white with a yellowish gray hue. It has weak bireflectance; anisotropy is distinct without color effects. The chemical composition (electron microprobe) is as follows, wt %: 20.66 S, 0.98 Se, 0.01 Cu, 0.03 Cd, 11.40 In, 12.11 Sn, 37.11 Pb, 17.30 Bi; the total is 99.60. The empirical formula calculated on the basis of 12 atoms is Pb1.92Sn1.09In1.06Bi0.89(S6.90Se0.13)7.03. The simplified formula is Pb2SnInBiS7. The strongest eight lines in the X-ray powder pattern [d, A (I)(hkl)] are 5.90(36)(100), 3.90(100)(111), 3.84(71)(112), 3.166(26)(114), 2.921(33)(115), 2.902(16)(200), 2.329(15)(214), 2.186(18)(125). The selected area electron diffraction (SAED) patterns of abramovite are quite similar to those of the homologous cylindrite series minerals. The new mineral is characterized by noncommensurate structure composed of regularly alternated pseudotetragonal and pseudohexagonal sheets. The structure parameters determined from the SAED patterns and X-ray powder diffraction data for pseudotetragonal subcell are: a = 23.4(3), b = 5.77(2), c = 5.83(1) A, α = 89.1(5) °, β = 89.9(7)°, γ = 91.5(7)°, V = 790(8) A3; for pseudohexagonal subcell: a = 23.6(3), b = 3.6(1), c = 6.2(1) A, α = 91(2)°, β = 92(1)°, γ = 90(2)°, V = 532(10) A3. Abramovite is triclinic, space group P(1). The new mineral is named in honor of Russian mineralogist Dmitry Abramov. The type material of abramovite has been deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow.

The system [Na2Ca(CO3)2 ]100− x − (50 wt.% NaCl + 50 wt.% KCl) x (10 < x < 80 wt.%), a join in the quaternary system Na2CO3 – CaCO3 – NaCl – KCl, has been investigated at temperatures ranging from 450° to 900°C at 0.1 GPa. Liquidus temperatures are on the order of 825°C, with a depression on the liquidus to 750°C at about 23 wt.% halide corresponding to a piercing point. Liquids that are poor in halides relative to the composition of the piercing point have a nyerereite-like (Na,Ca,K) carbonate as the primary liquidus phase; it coexists with a one-phase halide-rich liquid. Liquids with ~ 30–70 wt.% halide initially precipitate calcite as the primary liquidus phase. Below 700°C, calcite reacts with liquid to form nyerereite-like (Na,Ca,K) carbonate. From 600° to 550°C, this carbonate coexists with two immiscible halide liquids. Below the solidus at ~550°C, discrete exsolved inclusions of (Na,K)Clss occur in (K,Na)Clss and of (K,Na)Clss in (Na,K)Clss. These data are relevant to the differentiation and crystallization of the natrocarbonatitic melt at Oldoinyo Lengai under hypabyssal and plutonic conditions; they predict the formation of cumulate rocks composed of nyerereite, gregoryite, halite and sylvite. Disaggregation of such assemblages could lead to formation of sylvite–fluorite macrocrystal natrocarbonatite.

Szaibelyite, ideally MgBO 2 (OH), from the Potash Corporation of Saskatchewan (New Brunswick Division) mine at Penobsquis, Kings County, New Brunswick, occurs in the Upper Halite member of the Windsor Group evaporites, and is associated with halite, sylvite, anhydrite, hilgardite, volkovskite, hydroboracite, walkerite and pringleite. Electron-microprobe analysis, supported by a single-crystal analysis of its structure, yielded: MgO 47.92 (46.28–48.71), FeO 0.74 (0.22–3.05), MnO 0.04 (0.00–0.08), (ideal B 2 O 3 ) 41.77 and (ideal H 2 O) 10.81, for a total of 101.18 wt.%. The empirical formula based on three anions is (Mg 0.99 Fe 0.01 )B 1 H 1 O 3 . Szaibelyite is monoclinic, P 2 1 / a , with refined unit-cell parameters a 12.586(1), b 10.415(1), c 3.1340(3) A, β 95.923(2)°, V 408.6(1) A 3 , Z = 8. The crystal structure refined to an R index of 0.031 using 1,191 unique reflections. The corrugated (100) sheets of [MgO 6 ] octahedra are cross-linked by isolated clusters of [B 2 O 4 (OH)] polyhedra. The [OH] groups strengthen the cross-linkage with hydrogen bonding. The fundamental building block (FBB) within the structure, 2Δ:2Δ, is compared to that in the structures of other borates, such as suanite and clinokurchatovite.

A micromorphological study was carried out on salt affected soils from three locations on erosional terraces overlain by wash and alluvium under tropical savanna climate in Northeast Thailand where salinity problem has been acute. This aimed at providing detailed data for a better agricultural land use planning of the area. Five or six profiles at each location were sampled along a linear traverse that included the soils with highest and lowest levels of salt accumulation. Sixteen soil profiles were described, sampled and analyzed using physio-chemical, optical microscope and scanning electron microscope with energy dispersive spectrometer (SEM/EDS) techniques. The highest salt affected profiles show salt crusts, bare surfaces and halophytic plants and these soils have been left idle. All soils are deep, poorly drained, moderately to highly developed and with various salinity levels. They are fourteen Natraqualfs and two Endoaqualfs. Soil textures are sandy for location 1, clayey for location 2 and with a sandy topsoil and clayey subsoil for location 3. The soils at locations 1 and 2 mostly have high values of electrical conductivity (EC) and exchangeable sodium percentage (ESP). Soils at location 3 may have been affected by desalinization and alkalization as is indicated by low EC, high basic cations and high pH. Field morphology, optical micromorphology and SEM/EDS analysis results show clear accumulation of salt in some profiles. Their microstructures are different due to the difference in their texture. Compact grain and bridge grain structures are common in sandy-textured soil whereas channel and subangular blocky structures are common in the clayey soils. Quartz and runi-quartz grains are common as skeleton materials, but are present in different sizes and amounts. Halite occurs in voids in soils at locations 1 and 2 and is abundant in Pedons 1 and 6 where salt crusts exist. Calcite is present only in one profile (Pedon 1). Amorphous pedofeatures are manganiferrous impregnative nodules and iron and manganese oxide impregnated s-matrix. The EDS spectra indicate the presence of barite (BaSO 4 ) and sylvite (KCl) crystals in voids in some of the soils. The element composition of the soil matrix in a triangle graph of SiO 2 : Al 2 O 3 : Fe 2 O 3 is displaced from the ‘kaolin line’ towards the SiO 2 apex, indicating that very fine-grained quartz and/or a Si-rich clay mineral (s) is present in the matrix. The presence of Si-rich clay minerals is supported by XRD results that identified smectite in addition to kaolin and may be an evidence of the resilication process that can occur in salt affected soils. The data points near the Fe 2 O 3 apex of the triangle graphs represent iron oxide nodules and their position on the matrix Al 2 O 3 /SiO 2 line indicates that induration of the matrix with iron oxide has occurred and that the nodules have formed in situ . The normalized element composition of the matrix in triangle graph between SiO 2 : Al 2 O 3 : Na 2 O + CaO + MgO indicates that in some instances the salts of Na, Ca and Mg have indurated the soil matrix as data points for salt-rich matrix fall on the clay matrix composition line.

This study is an application of the experimental design methodology for optimizing a potassium sulfate synthesis reaction. The latter is a two-stage reaction through an intermediate product (Schoenite: K2SO4.MgSO4·6H2O). To determine optimal experimental conditions of the first stage, we have conducted a fractional factorial design and a central composite one. The optimal conditions of the second stage were determined only by means of a fractional factorial design. Several physico-chemical techniques were used to implement this study, namely potentiometry, complexometry, gravimetry and X-ray diffraction. This work has showed that this double decomposition reaction, when performed under the determined optimal conditions, gives good quality potassium sulfate (purity more than 95%) with a maximal yield. Copyright © 2008 John Wiley & Sons, Ltd.

Struvite (MgNH 4 PO 4 .6H 2 O) is one of phosphate minerals, commonly forms into aqueous solutions. It can be precipitated as mineral deposits for optimization of phosphate recovery based on the pH optimum, molar ratio and temperature levels. This paper presents results of a study on the struvite precipitation under the influence of pH variation, at optimized molar ratio and temperature, which were calculated from an experimental design methodology. Based on the methodology, a laboratory prepared struvite, made by mixing solutions to NH 4 OH, MgCl 2 and H 3 PO 4 for a molar ratio of 1: 2: 1 in a 500 mL volume of batch stirred crystallizer at room temperature. The crystallization was done at 200 rpm and the pH variation was adjusted to 8, 9 and 10 with KOH for a time of 70 minutes. The resulting crystals were filtered and dried at room temperature for 48 h and subsequently stored for further analysis. Material characterisasion of the crystals was conducted using XRPD Rietveld method of mineralogical composition. SEM equipped by EDX was employed for investigation of morphology and elemental composition of the crystals obtained. During the experiment, struvite crystals were firstly nucleated and subsequently developed at major value. The increase in pH is assumed to convert some of the struvite phase into struvite (K) and minor sylvite (KCl). It demonstrates that Visual MINTEQ can be employed to estimate the mineral formation out the synthetic solutions.

Natural potash evaporites are a typical part of a brine evaporation series, crystallizing at the higher concentration or bittern end, either at the surface (primary salts) or in the shallow subsurface (secondary salts). Today, bedded accumulations of primary potash evaporites are a relatively rare occurrence. Extremely high solubility of most potash salts means they accumulate in highly restricted, some would say highly continental, modern depositional settings (Cendon et al. 2003). Wherever Quaternary potash does occur naturally, as in the playas of the intermontane Qaidam Basin in China and in the Danakil Depression in the Afar Rift of Africa, carnallite, not sylvite, is the dominant potash salt. This has led some to postulate that carnallite is the archetypal primary marine potash phase, while sylvite is a secondary diagenetic mineral formed by incongruent dissolution of carnallite. Others have argued that ancient sylvite was sometimes a primary precipitate, deposited by the cooling of highly saline surface or near surface brines and from seawater with ionic proportions different to those of today (Hardie 1996).

The experiment selected zeolite from ten absorption agent to adsorb potassium. Through the investigated of amount of zeolite, adsorption time and temperature, found the best parameters. When zeolite was used with 2g, adsorption time was 60min and temperature was 20˚C,the extraction rate was 66.67%.The result show that zeolite can be reused.

Crystallization of struvite [MgNH 4 PO 4 .6H 2 O] may lead to the deposition of scale which may create significant problems in the process pipes, pumps and other industrial equipment. However, struvite precipitation can be benefited for phosphate recovery for use of fertilizer. The aim at the present work was to investigate calcium additive on struvite precipitation. The experiment was carried out in a batch mode using a 1-liter Pyrex glass vessel mechanically agitated for 200 rpm. The scale-forming solution was prepared for mixing solutions to MgCl 2 and NH 4 H 2 PO 4 with Mg +2 , NH 4 + and PO 4 -3 in a molar ratio of 1: 1:1. The crystallization temperature of 30 and 40 °C was selected. Ca was added into the crystallizing solution to chloride dihydrate 0.4M (CaCl 2 •2H 2 O). Then each solution was pH adjusted to 9 by addition of KOH. The crystals obtained were characterized using SEM for morphology, EDS for elemental analysis as well as XRPD Rietveld analysis for crystaline phases. The induction periods varied from 10 to 90 min, which means that the struvite crystals began forming 10 to 90 min after mixing of the solution. It was observed that the Ca additive may inhibit the struvite crystallization. SEM analysis revealed that the struvite crystals obtained were predominantly of irregular prismatic morphology. Furthermore, the EDS pattern revealed that the elemental composition of the crystals consisted of Ca, Cl, S Mg, N, and P, providing that many crystalline phase found in the crystals such as Gypsum, CaCl 2 , struvite, struvite-(K) and sylvite. It was observed that the Ca additive appeared to inhibit the struvite crystallization.

Traditionally, potash mineral deposits have been characterized using downhole geophysical logging in tandem with geochemical analysis of core samples to establish the critical potassium (% K2O) content. These techniques have been employed in a recent exploration study of the Permian evaporite succession of North Yorkshire, United Kingdom, but the characterization of these complex deposits has been led by mineralogical analysis, using quantitative X-ray diffraction (QXRD). The novel QXRD approach provides data on K content with the level of confidence needed for reliable reporting of resources and also identifies and quantifies more precisely the nature of the K-bearing minerals. Errors have also been identified when employing traditional geochemical approaches for this deposit, which would have resulted in underestimated potash grades. QXRD analysis has consistently identified polyhalite (K2Ca2Mg(SO4)4·2(H2O) in the Fordon (Evaporite) Formation and sylvite (KCl) in the Boulby Potash and Sneaton Potash members as the principal K-bearing host minerals in North Yorkshire. However, other K hosts, including kalistrontite (K2Sr(SO4)2) a first recorded occurrence in the UK, and a range of boron-bearing minerals have also been detected. Application of the QXRD-led characterization program across the evaporitic basin has helped to produce a descriptive, empirical model for the deposits, including the polyhalite-bearing Shelf and Basin seams and two, newly discovered sylvite-bearing bittern salt horizons, the Pasture Beck and Gough seams. The characterization program has enabled a polyhalite mineral inventory in excess of 2.5 billion metric tons (Bt) to be identified, suggesting that this region possesses the world’s largest known resource of polyhalite. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.

Insula 104 is a residential area dating to the proto-Byzantine period (second century AD), inside the wide archaeological site of Hierapolis of Phrygia (Turkey). Today, the domus, which probably belonged to one of the aristocratic families of the city, has been damaged due to salt crystallization on the wall paintings of some of the rooms. In order to select the best type of conservation interventions, various diagnostic techniques were used to determine the nature and the origin of the soluble salts. In particular, the wall paintings from room A 1207 in the House of the Doric Courtyard and room A 1267 in the House of the Painted Inscription were investigated by non-invasive techniques, followed by sampling for laboratory analyses. Rising damp combined with the presence of salts is a critical issue for the aforementioned wall paintings. On site screening by portable techniques (IR thermography, Quantofix test strips) was performed to address the microsampling for the analyses. The data on both the chemical and mineralogical composition of the efflorescences revealed the presence of sulphates (mainly thenardite, aphthitalite and syngenite), sodium and potassium nitrates, and chlorides (halite and sylvite). The original and restoration mortars were also analysed to examine their impact on the conservation state of the wall paintings. The distribution of the salts and their typologies inside each room was correlated to the different uses of the rooms over the centuries and to previous restoration works. (C) 2016 Elsevier B.V. All rights reserved.

Calcium oxalate crystals are by far the most prevalent and widely distributed mineral deposits in higher plants. In Tradescantia pallida, an evergreen perennial plant widely used as an ornamental plant, calcium oxalate crystals occur in the parenchymal tissues of stem, leaf, and root, as well as in flower organs, in the form of either raphides or tetragonal prismatic crystals or both. Energy-dispersive X-ray analysis revealed that C, O, and Ca were the main elements; and K, Cl, and Si, the minor elements. Infrared and X-ray analyses of crystals collected from these tissues detected the coexistence of two calcium oxalate chemical forms, i.e., whewellite and weddellite, as well as calcite, opal, and sylvite. Here, we show for the first time the occurrence of epitaxy in mineral crystals of plants. Epitaxy, which involves the oriented overgrowth of one crystal onto a second crystalline substrate, might explain how potassium chloride (sylvite) – one of the most water-soluble salts – stays insoluble in crystal form when coated with a calcium oxalate epilayer. The results indicate the potential role of crystals in regulating the ionic equilibrium of both calcium and potassium ions.

The thermal behaviour of the animal by-product meat and bone meal (MBM) has been investigated in order to assess how it is affected structurally and chemically by incineration. Initially composed of intergrown collagen and hydroxyapatite (HAP), combustion of the organic component is complete by 650 °C, with most mass loss (50–55%) occurring by 500 °C. No original proteins were detected in samples heated at 400 °C or above. Combustion of collagen is accompanied by an increase in HAP mean crystallite size at temperatures greater than 400 °C, from 10 nm to a constant value of 120 nm at 800 °C or more. Newly formed crystalline phases appear beyond 400 °C, and include β-tricalcium phosphate, NaCaPO4, halite (NaCl) and sylvite (KCl). Crystallite thickness as judged by small angle X-ray scattering (SAXS) increases from 2 nm (25–400 °C) to 8–9 nm very rapidly at 550 °C, and then gradually increases to approximately 10 nm. The original texture of HAP within a collagen matrix is progressively lost, producing a porous HAP dominated solid at 700 °C, and a very low porosity sintered HAP product at 900 °C.

The Fenghuangshan Cu-Fe-Au deposit is located in Tongling, Anhui province in central-east China, within the Middle-Lower Yangtze River polymetallic belt. The mineralization is related to Late Yanshanian magmatic intrusions emplaced in Lower Triassic limestones and is divided into two episodes. The first and more important, episode A, is related to granodiorite-granodiorite porphyry and characterized by massive, disseminated, veinlet- and breccia-style mineralization in skarn formed at the contact zone, whereas the second, episode B, is related to a quartz monzodiorite porphyry stock which crosscuts the previous skarn and is characterized by disseminated and veinlet-style mineralization within the porphyry. Based on mineral assemblages and their crosscutting relationships, the hydrothermal evolution of episode A is further divided into five substages (A1–A5), and that of episode B into four (B1–B4), among which A4, A5, and B3 are the main copper mineralization stages. This paper focuses on microthermometric studies of fluid inclusions in the various stages, with an aim to characterize the thermal and compositional evolution of hydrothermal fluids and to discuss their implications for mineralization in terms of fluid sources and metal deposition mechanisms. Fluid inclusions were studied in garnet, quartz, and calcite from stages A1, A4, A5, B1, B2, B3, and B4. Four types and 13 subtypes of fluid inclusions were distinguished based on fluid composition and phase assemblages. Type I fluid inclusions contain one or more salt daughter minerals (halite and sylvite) and homogenize into the liquid phase, whereas type II inclusions homogenize into the vapor phase, both commonly containing an opaque daughter mineral. Type III fluid inclusions are aqueous inclusions that do not contain daughter minerals and homogenize into the liquid phase, and type IV inclusions are CO2 bearing, homogenize to the CO2 or the aqueous phase, and commonly contain an opaque daughter mineral. Primary fluid inclusions in stage A1 are of type I and II, interpreted to represent two immiscible phases resulting from boiling, and those in stages A4 and A5 are of type III. Stages B1 and B2 are characterized by type I primary inclusions, and stages B3 and B4 by type III. Type IV inclusions occur as secondary inclusions in B1 quartz and are interpreted to be related locally to B3 stage mineralization. Microthermometric data indicate a trend of decreasing temperatures and salinities from early to late stages for both mineralization episodes, reflecting a change from a magmatic fluid-dominated system to one invaded by fluids from the country rocks and meteoric water. The fact that the main stages of mineralization (A4, A5, B3) coincided with the development of fluid inclusions without daughter minerals of salt suggests that sulfide precipitation did not take place until the system was diluted by cooler fluids with lower salinities. However, the observation that the fluid inclusions hosted in minerals before sulfide mineralization (i.e., stages A1, B1, and B2) commonly contain opaque daughter minerals inferred to be sulfides suggests that the ore-forming components were likely derived from the higher temperature magmatic fluids, and the fluids derived from the country rocks mainly contributed to the precipitation of sulfides through mixing and cooling.

The data on the mineral composition and crystallization conditions of magnesian skarn and magnetite ore at contacts of dolerite with rock salt and dolomite in ore-bearing volcanic—tectonic structures of the Angara—Ilim type have been integrated and systematized. Optical microscopy, scanning and transmission electron microscopy, electron microprobe analysis, electron paramagnetic resonance, Raman and IR spectroscopy, and methods of mineralogical thermometry were used for studying minerals and inclusions contained therein. The most diverse products of metasomatic reactions are found in the vicinity of a shallow-seated magma chamber that was formed in Lower Cambrian carbonate and saliferous rocks under a screen of terrigenous sequences. Conformable lodes of spinel-forsterite skarn and calciphyre impregnated with magnesian magnetite replaced dolomite near the central magma conduit and apical portions of igneous bodies. At the postmagmatic stage, the following mineral assemblages were formed at contacts of dolerite with dolomite: (1) spinel + fassaite + forsterite + magnetite (T = 820−740°C), (2) phlogopite + titanite + pargasite + magnetite (T = 600–500°C), And (3) clinochlore + serpentine + pyrrhotite (T = 450°C and lower). Rock salt is transformed at the contact into halitite as an analogue of calciphyre. The specific features of sedimentary, contact-metasomatic, and hydrothermal generations of halite have been established. The primary sedimentary halite contains solid inclusions of sylvite, carnallite, anhydrite, polyhalite, quartz, astrakhanite, and antarcticite; nitrogen, methane, and complex hydrocarbons have been detected in gas inclusions; and the liquid inclusions are largely aqueous, with local hydrocarbon films. The contact-metasomatic halite is distinguished by a fine-grained structure and the occurrence of anhydrous salt phases (CaCl2 · KCl, CaCl2, nMgCl2 · mCaCl2) and high-density gases (CO2, H2S, N2, CH4, etc.) as inclusions. The low-temperature hydrothermal halite, which occurs in skarnified and unaltered silicate rocks and in ore, is characterized by a low salinity of aqueous inclusions and the absence of solid inclusions. The composition and aggregative state of inclusions in halite and forsterite indicate that salt melt-solution as a product of melting and dissolution of salt was the main agent of high-temperature metasomatism. Its total salinity was not lower than 60%. The composition and microstructure of magnetite systematically change in different mineral assemblages. Magnetite is formed as a result of extraction of iron together with silicon and phosphorus from dolerite. The first generation of magnetite is represented by mixed crystals, products of exsolution in the Fe-Mg-Al-Ti-Mn-O system. The Ti content is higher at the contact of dolerite with rock salt, whereas, at the contact with dolomite, magnetite is enriched in Mg. The second generation of magnetite does not contain structural admixtures. The distribution of boron minerals and complex crystal hydrates shows that connate water of sedimentary rocks could have participated in hydrothermal metasomatic processes.

The phase-mineral composition of the feed coal (FC) from Maritza East lignite used in the Maritza East 1 thermo-electric power station (TEPS) and lagooned ashes (LAs) generated from the burning of this lignite was studied. The concentration and behaviour of 19 trace elements in the FC and LAs, as well as in the soils and plants collected from the restored sites of former LA disposals are also described. The minerals and inorganic phases identified in the lignite include quartz, kaolinite, pyrite, illite, plagioclase, gypsum, calcite, sulphur, marcasite, pyrrhotite, magnetite, K-feldspar, barite, szomolnokite, other Fe sulphates, sylvite, Ni carbonate or oxide/hydroxide, and glass. The phase composition of LAs is represented by original lignite minerals (pyrrhotite, magnetite, quartz, kaolinite) and newly formed minerals and phases generated during the combustion process (pyrrhotite, magnetite, hematite, quartz, metakaolinite, mullite, indialite, glass, char) or storage of LAs (sulphur, hematite, Fe hydroxides, gypsum, barite, Fe sulphates, calcite, sylvite). It was found that Cr, Cu, and Ti in the lignite ashes, and Co, Cr, Cu, Mn and Ni in LAs are relatively enriched in comparison with their respective Clarke values (worldwide average contents) for lignite and subbituminous coal ashes. The concentrations of Ag, Ba, Be, Co, Cu, Ga, Mo, Ni, Rb, Sn, and Ti in the soils have contents higher than their Clarke values for soils. The abundance of these elements plus Mn, V, and Zn in soils is probably related to some occurrence of discrete minerals and phases containing such elements. The contents of Be, Cr, Ga, Li, Ni, Pb, Ti, and V in the plants growing on these restored LA sites have concentrations higher than their Clarke values for land plants (dry basis). The water-soluble modes of occurrence of Ag, Ba, Be, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sn, Ti, and Zn in soils and/or LAs, as well as the plant affinity to these elements should have a leading role for their concentration in plants. The present results reveal that various trace elements with environmental concern could be potential pollutants of surface and subsoil waters, soils and plants in the areas of restored LA sites.

A series of flotation tests on coarse KCl particles in brine solution prepared from potash ore from the Taquari Vassouras mine (Companhia Vale do Rio Doce; CVRD), Aracaju, Brazil was carried out to determine the recovery of sylvite in the presence of high concentrations of Mg 2+ . The introduction of Mg 2+ caused the precipitation of fine salt crystals that consist mostly of NaCl (90%+) but also some KCl. However, the introduction of Mg 2+ also caused the nucleation of fine crystals of NaCl and KCl on the surface of the coarse KCl in the flotation feed. The nucleation of these fine surface crystals on the coarse KCl may have added to a (net) improvement in the recovery of the coarse KCl. However, a precipitate of fine NaCl with some KCl crystals, competed for collector and caused depression of the coarse KCl. When these precipitates were removed before collector addition, the collector subsequently adsorbed on the coarse KCl and the recovery of coarse KCl improved significantly.

The compositions of parental magmas forming kimberlitic rocks remain largely unknown because of masking effects of syneruptive contamination and degassing, and post-magmatic alteration. Among most affected elements are volatiles (H2O and CO2) and alkalies (Na and K). This study attempts to overcome the problems related to the alteration of kimberlites by detailed petrographic and chemical analyses of exceptionally fresh, and thus essentially anhydrous (< 0.5 wt.% H2O), kimberlite samples from the Udachnaya-East pipe (Daldyn-Alakit region, Siberia). The groundmass of these kimberlites contains abundant carbonate (calcite, shortite, zemkorite) and chloride (halite, sylvite) minerals, cementing olivine phenocrysts, and forming round segregations ("nodules"). The nodules, belonging to the chloride and chloride-carbonate types, show no evidence of thermometamorphic effects on the contacts with the host kimberlite. The chloride-carbonate nodules demonstrate liquid immiscibility textures that are remarkably similar to those observed in the olivine-hosted chloride-carbonate melt inclusions at similar to 600 degrees C. The similarity of oxygen and carbon isotope values of carbonates from the groundmass and nodules (delta O-18 12.5 to 13.9 parts per thousand VSMOW; delta C-13 -3.7 to -2.7 parts per thousand VPDB) points to their common origin at similar temperatures. We argue for crystallisation of the chloride-carbonate nodules from residual kimberlite melts, pooled after exhaustion of the silicate melt component. The enrichment of the residual melt in alkali carbonate and chloride is partly reflected in the bulk groundmass compositions (10-11 wt.% CO2, 2.3-3.2 wt.% Cl, 2.6-3.7 wt.% Na, and 1.6-2.0 wt.% K). We propose that this enrichment is inherited from the kimberlite parental magma, and it can be responsible for the kimberlite low liquidus temperatures, low viscosities, and rapid emplacement.

A comprehensive examination and treatment of 49 students aged 20-25 years diagnosed chronic generalized catarrhal gingivitis (CGCG) were held. Depending on the methods of treatment were created into two groups of observation. The main group comprised 24 patients who along with dental sanitation and treatment of gingivitis took the course of salt treatment for 17 days, as opposed to control group. Hygienic researches and mineralthcrapy were held in a special room (23.6 m2). equipped with sylvite blocks with a total reaction surface 5 m2, salt filters with air ducts filled with wooden plates with mineral fragments. The study of the effectiveness of a comprehensive treatment of young patients with CGCG allowsto gel an information of the positive impact of salt therapyon the clinical condition of marginal periodontal tissues and indeces of oral cavity local immunity. The main curative factorsforming the internal environment of silvinite structures are multicomponent highly dispersed salt aerosol with a defined particle size and aeroionization. Natural salts complex consisting of chlorides of potassium, sodium and magnesium has an anti-inflammatory and immuno-modulating effects.Проведено комплексное обследование и лечение 49 пациентов в возрасте 20-25 лет с диагнозом хронического генерализованного катарального гингивита (XГКГ). В зависимости от методов лечения были сформированы 2 группы. В группе наблюдения (n=24) наряду с санацией полости рта и лечением гингивита проводили курс солелечения в течение 17 дней; в группе сравнения (n=25) минералотерапию не осуществляли. Гигиенические исследования и минералотерапию проводили в специальном помещении площадью 23,6 м2, оборудованном блоками сильвинита с общей реакционной поверхностью 5 м2. Основными лечебными факторами внутренней среды сильвинитовых сооружений являются многокомпонентный высокодисперсный соляной аэрозоль и аэроионизация (легкие отрицательные аэроионы). Природный минерал сильвинит, состоящий из хлоридов калия, натрия и магния, оказывает противовоспалительное и иммуномодулирующее действие на организм. Изучение эффективности комплексного лечения лиц молодого возраста с ХГКГ позволило получить сведения о позитивном влиянии минералотерапии на клиническое состояние тканей маргинального пародонта и показатели местного иммунитета полости рта.

Carbonatites of the Jacupiranga alkaline–carbonatite complex in Sao Paulo State, Brazil, were used to investigate mineral–fluid interaction in a carbonatite magma chamber because apatite showed a marked discontinuity between primary fluid inclusion-rich cores and fluid inclusion-poor rims. Sylvite and burbankite, apatite, pyrite, chalcopyrite and ilmenite are the common phases occurring as trapped solids within primary fluid inclusions and reflect the general assemblage of the carbonatite. The apatite cores had higher Sr and REE concentrations than apatite rims, due to the presence of fluid inclusions into which these elements partitioned. A positive cerium anomaly was observed in both the core and rim of apatite crystals because oxidised Ce4+ partitioned into the magma. The combined evidence from apatite chemistry, fluid inclusion distribution and fluid composition was used to test the hypotheses that the limit of fluid inclusion occurrence within apatite crystals arises from: (1) generation of a separate fluid phase; (2) utilization of all available fluid during the first stage of crystallization; (3) removal of crystals from fluid-rich magma to fluid-poor magma; (4) an increase in the growth rate of apatite; or (5) escape of the fluids from the rim of the apatite after crystallization. The findings are consistent with fractionation and crystal settling of a carbonatite assemblage in a fluid-stratified magma chamber. Secondary fluid inclusions were trapped during a hydrothermal event that precipitated an assemblage of anhedral crystals: strontianite, carbocernaite, barytocalcite, barite and norsethite, pyrophanite, magnesian siderite and baddeleyite, ancylite-(Ce), monazite-(Ce) and allanite. The Sr- and REE-rich nature of the secondary assemblage, and lack of a positive cerium anomaly indicate that hydrothermal fluids have a similar source to the primary magma and are related to a later carbonatite intrusion.

Stalactites formed by the chemical weathering of natrocarbonatite lava decorate the roofs of hollow inactive hornitos at Oldoinyo Lengai, Tanzania. The stalactites are composed principally of trona with lesser and very variable amounts of nahcolite, (NaHCO3), thermonatrite (Na2CO3.H2O), aphthitalite [(K,Na)3Na(SO4)2], kogarkoite [Na3(SO4)F], schairerite [Na21 (SO4)7F6Cl], halite and sylvite. Stalactites are considered to form by the evaporation of Ca-free highly alkaline brines seeping from the altered lavas which form the roofs of the hornitos. The principal subaerial weathering products of natrocarbonatite, i.e. pirsonnite, gaylussite, shortite and calcite are not found in the stalactites and are retained in the altered lavas of the homito roof. Fluorine required for the formation of kogarkoite and schairerite is derived from the decomposition of fluorite at high pH (>10). Sulphur is derived from the decomposition of gregoryite.

Lapilli formed by a Strombolian eruption are associated with the formation of a large lava flow of natrocarbonatite on or about 21–22 July, 2000 at Oldoinyo Lengai volcano, Tanzania. Fresh lapilli consist of vesicular natrocarbonatite similar to that occurring in rapidly quenched lavas. The lapilli were altered at low temperature (5–4.5PO4(CO3,F,Cl) that is not similar to that of nahpoite (Na2HPO4), dorfmanite [Na2(PO3OH).2H2O] or natrophosphate [Na7(PO4)2F.19H2O]. However, in common with these minerals, it is ephemeral and undergoes rapid decomposition under normal atmospheric conditions. The sodium phosphate-carbonate and associated halide-sodium carbonate assemblages are considered to be a part of a previously unrecognized hyperagpaitic assemblage forming as sublimates at Oldoinyo Lengai.

Analyses of primary and early diagenetic fluid inclusions in the halite from the Late Ordovician Mallowa Salt, Canning Basin, Western Australia indicate a Ca-rich composition and high concentration of parent brines in the basin which were close to sylvite and carnallite precipitation. The salt-bearing series in the sampled interval was overheated up to 62 °C. The recorded differences in gas compositions result from the input of several gas sources including dispersed organic matter in the salt series and hydrocarbon deposits in the underlying rocks. The high concentration of the brines in fluid inclusions does not allow quantitative reconstruction of the chemical composition of Late Ordovician parent seawater. Using the information from Early Cambrian and Late Silurian basins as a proxy, however, the new data indicate that Late Ordovician seawater was undoubtedly Ca-rich and, in comparison with modern seawater, had a similar K content, considerably lower Mg content (c. 30%), approximately three times the Ca content and one-third the SO4 content.

The Sambhar and Didwana playas from the eastern margin of the Thar Desert (annual precipitation of 300–450 mm) have been investigated for mineralogy, major and trace element geochemistry of near surface sediments. Geochemical data and evaporite mineralogy of sediments from the playa surface and shallow depths provide insight to the present-day geochemical processes and the different vertical phases of pore water activity. Detrital minerals from both the playas reflect igneous and metamorphic source rocks in their catchments. The zeolite type mineral, analcime (NaAlSi 2 O 6 ·H 2 O ) is assumed to be authigenic in origin, a product of chemical reaction between the hypersaline brine and detrital feldspars. The evaporite mineralogy is dominated by halite, calcite and dolomite. Major differences between the evaporite mineralogy of the surface sediments of two playas are the occurrence of trace amounts of the H 2 O-bearing carbonate, trona (Na 3 H(CO 3 ) 2 · 2H 2 O), in the Didwana and K- and Mg-bearing sulphate and chloride minerals e.g. polyhalite (K 2 MgCa 2 (SO 4 ) 4 · 2H 2 O), carnallite (KMgCl 3 · 6H 2 O), and sylvite (KCl) in the Sambhar. Based on the distribution of major and trace elements, the surface sediments from both playas are divided into three geochemical zones. Fed by river and rainwaters, the playa surfaces show enrichment of insoluble cations and hydrolysates in the outermost zone and soluble oxides and cations in the innermost zone. Further, the shallow depth profiles are also divided into distinct geochemical zones based on the elemental ratios. The sub-recent zone I reflects low chemical weathering and higher aeolian input, the middle zone II indicates relatively higher weathering index and zone III, enriched in evaporites, also shows low chemical weathering. Despite the fact that the Sambhar and Didwana are separated only by ∼50 km, they show significant differences in terms of evaporite mineralogy and inorganic composition of surface sediments. We interpret this to be a manifestation of local variations in precipitation, inflow and aeolian influx.

Natrocarbonatite lavas erupted from hornitos T37B and T49B at Oldoinyo Lengai (Tanzania) during 23–30 July, 2000 are unusual in containing sylvite and fluorite microcrysts together with fluorite-nyerereite intergrowths. The latter are relatively coarse grained and exhibit granular textures indicative of slow crystallization rates relative to those of their host subaerial lavas. Fluorite microcrysts are considered to be derived by the fragmentation of the fluorite-nyerereite clasts. Sylvite microcrysts contain inclusions of ferroan alabandite [(Mn0.67-0.71Fe0.33-0.29)S] and are poor in Na (1.9–7.7 wt.% Na; 6.1–23.4 mol.% NaCl). Intergrowth and microcrystal fluorite contains 1–3.5 wt.% Sr. Intergrowth nyerereite has a composition similar to that occurring as bona fide phenocrysts. The groundmass of lava erupted from hornito T37B contains nyerereite microphenocrysts (4–8 wt.% BaO) that are epitaxially mantled by barian nyerereite (12–20 wt.% BaO). The latter are compositionally and texturally distinct from the groundmass phase X, which is considered to be a burbankite-group mineral. The fluorite-nyerereite clasts are considered to be derived from the magma chamber underlying hornitos T37B and T49B, and thus representative of some of the products of crystallization of natrocarbonatite magma under hypabyssal conditions. The origins of the sylvite microcrysts cannot, as yet, be determined.

Sodium chloride and the secondary salts, such as sylvite, mirabilite, thenardite, bloedite, carnalite, bischofite, kieserite and polyhalite are not only mined from evaporate deposits, but they have also been produced more economically by solar concentration of brines for centuries. In this study, as an alternative approach, the aim was to create the production of salt co-products together with pure sodium chloride (NaCl) during the NaCl producing period from the Salt Lake water by multiple evaporation-cooling methods, supplemented by mineral and chemical processing. The results of XRD analysis indicated that various types of salts such as pure halite (sodium chloride), sodium sulphate salts, halite + carnalite, halite + langbeinite + sylvite and halite + bischofite + kieserite can be produced as participated materials from the brine of the Salt Lake. © 2005 Elsevier B.V. All rights reserved.

The mineralogy of atmospheric particles at the confluence of the Tinto and Odiel rivers, south of Huelva (a highly industrialized city in the SW Spain), was characterized in view to identify source origins. In spite of the small amount of sample collected, mineralogical characterization was performed by X-ray diffraction, polarized light microscopy and scanning electron microscopy with EDS analysis system, using an adequate sample preparation methodology. Sedimentable (SP) and aerosols particles were sampled an one-week basis every two months for one year. Quartz, calcite and feldspars were found to be the major minerals in both fractions, and phyllosilicates, dolomite and gypsum were also identified in lower content. Minor mineral particles included barite, apatite, sphalerite and pyrite. SEM studies revealed the additional presence of chalcopyrite in both SP and aerosols, and of chalcocite–covellite, halite and sylvite in the latter. Siderite, hematite and ankerite were only detected in the SP fraction. The concentrations of the previous minerals increased in summer by effect of the limited rain and the resulting scarcity of atmosphere washing. Non-mineral particles detected by SEM in SP and aerosol fractions included spherical, biological and compositionally complex particles. The main source of mineral particles was found to be the soil suspension in addition to the metallurgical and fertilizer production industries in the area.

The Kafubu Emerald Area in Zambia is an important producer of gemstone-quality emeralds. These are hosted mostly by metasomatic phlogopite-rich zones (max. 2 m wide) that rim numerous pegmatite dykes and epigenetic quartz-tourmaline veins in Mg-rich metabasites. Where these dykes/veins occur in other rock types, the phlogopite-rich zones are either missing, or are very narrow and free of emeralds. Three types of hydrothermal quartz-tourmaline mineralization were identified: banded fine-grained rock, discordant to semiconcordant veins and late veins. A fluid inclusion study of the discordant type of veins revealed the presence of aqueous-carbonic and aqueous fluids. The earliest fluids (mostly trapped in the quartz, rarely in beryl) represent complex H 2 O–CO 2 –N 2 –CH 4 –NaCl–CaCl 2 mixtures (X CO2 : 0.25 to ∼0.04) with traces of N 2 and CH 4 only (generally As for their salinity, low-, medium-, and high-salinity fluids were distinguished (0–10, 12–25, and > 34 wt.% NaCl eq., respectively). Each salinity class usually comprises both aqueous-carbonic and aqueous fluids. Solid phases present in inclusions were studied by Raman, and/or by SEM-EDX. Daughter phases include: halite, sylvite, and Fe–Mn-carbonate. Accidental phases are quartz, beryl, carbonate, nahcolite, pyrophyllite(?) and muscovite(?). The oxygen isotope composition (δ 18 O) of quartz and tourmaline is quite homogeneous (10.9 ± 1‰ and 8.4 ± 0.7‰ SMOW respectively) and yield vein-formation temperatures of 350–450 °C and parent fluid composition + 5 to + 7‰ SMOW. Three evolution stages of quartz-tourmaline ± beryl mineralization are inferred from fluid isochores and isotope thermometry: early (620–400 MPa and 450–350 °C), main (400–150 MPa and 450–350 °C) and late (∼250–200 MPa and 350–280 °C). The early stage includes formation of banded quartz-tourmaline rocks and of some quartz-tourmaline veins. Most of the studied quartz-tourmaline veins and all studied beryls were formed within the main stage. Late stage corresponds to the formation of late quartz-tourmaline veins with lamellar tourmaline-quartz intergrowths.

The evolution of magnesium chloride brines with high bromide contents via a multistage reaction and dissolution process has been studied in brine seeps of a German potash mine. The observed chemical trends and phase equilibria can be modeled and interpreted in terms of a NaCl solution (cap rock brine) infiltrating into a potash zone characterized by the metamorphic mineral assemblage kieserite + sylvite + halite + anhydrite. Establishment of a persistent, stable equilibrium assemblage and constant fluid composition in the invariant point IP1 of the six component (Na-K-Mg-Ca-Cl-SO4-H2O) system of oceanic salts is prevented by the perpetually renewed input of NaCl-brine and by the intermittent exposure of incompatible kieserite. Instead, the solutions develop towards the metastable invariant point IP1(gy), with the mineral assemblage carnallite + polyhalite + sylvite + halite + gypsum, where gypsum takes the place of anhydrite (stage I). The temporary exposure of kieserite and the ensuing formation of polyhalite effectively buffer the solutions along the metastable polyhalite phase boundary during stages II and III. Eventually, in stage IV, polyhalite becomes depleted and admixture of more NaCl brine leads to low sulfate solution compositions, which are now only constrained by carnallite + sylvite + halite, and the once hexary system degenerates to a quaternary one (Na-K-Mg-Cl-H2O) in point E. Bromide in brines shows equilibrium partitioning with respect to the wall rock minerals. The pattern of evolving brine compositions may serve as a model for similar brine occurrences, which in some cases may have been misinterpreted as remains of fossil, highly concentrated and chemically modified seawater. Similar magnesium chloride brines of salt lakes (e.g., Dead Sea, Dabusun Lake) show subtle differences and are constrained by fewer mineral equilibria (more degrees of freedom), and their low sulfate contents are due to gypsum precipitation, driven by calcium chloride input from dolomitization reactions. Finally, the observed reaction sequence is generalized, and a model for the formation of magnesium sulfate depleted, chloride-type potash salts and bischofite deposits by leaching of sulfate-type evaporites is proposed.

Accurate knowledge of the concentrations of potassium and other elements is critical for evaluating the effects of straw and other high-fouling biomass fuels in combustion boilers and other thermal systems. Development of accurate and precise analytical procedures is therefore essential for utilization of biomass fuels in energy production and high-temperature applications. By comparing the results of X-ray fluorescence (XRF) analyses with similar analyses done using instrumental neutron activation (INA), it is observed that 20−25% of the original K2O content of straw ashes and slag can be lost during sample preparation for analyses. The loss occurs during heating of the ashes to determine loss on ignition probably as a result of the breakdown of sylvite (KCl). This loss can be significantly reduced, but not completely eliminated, if the analyses are performed on ashes that have not previously been heat-treated. The study poses the cautionary note that similar losses may occur during XRF analyses of other...

Sabkha deposits in the geologic record are commonly used to interpret the environmental conditions of deposition. Implicit in this use is the assumption that the solute system is chemically closed, that is, the authigenic minerals represent the composition of the fluids in their environment of origin. Thermodynamic and mass-balance calculations based on measurements of water and solute flux of contemporary Abu Dhabi coastal sabkha system, however, demonstrate that the system is open for sodium and chloride, where nearly half of the input is lost, but closed for sulfur, where nearly 100% is retained. Sulfur and chloride isotopes were consistent with this observation. If these sabkha deposits were preserved in the geologic record, they would suggest a solute environment rich in sulfate and poor in chloride; yet the reverse is true. In most coastal-sabkha environments, capillary forces bring solutes and water to the surface, where the water evaporates and halite, carnallite, sylvite, and other soluble minerals are precipitated. Retrograde minerals, such as anhydrite, calcite, dolomite, and gypsum, however, precipitate and accumulate in the capillary zone beneath the surface of the coastal sabkha. Because they possess relatively low solubility and are below the surface, these retrograde minerals are protected from dissolution and physical erosion occurring from infrequent but intense rainfall events. Thus, they are more likely to be preserved in the geological record than highly soluble minerals formed on the surface.

An asymmetric binary Margules formulation for excess Gibbs energy, enthalpy, and entropy is adequate to describe the 1 bar halite-sylvite solvus in NaCl-KCl (Thompson and Waldbaum 1969). However, a binary Margules formulation is not adequate to describe excess volumes of single-phase chlorides in P-V-T-X from ambient P-T to ~20 kbar and 700 °C. Excess volumes across NaCl-KCl increase with temperature, decrease with pressure, and show systematic deficits in the consolute region. These patterns can be explained by the importance of a third component—vacancy defects that relieve the lattice stresses of K-Na size mismatch. New, two-phase observations in P-V-T-X allow delineation of the excess Gibbs energies to high pressures where the excess enthalpies and entropies do not depend on T at each P , but show significant variation between 1 bar and ~20 kbar. The volume, entropy, and enthalpy of K-Na mixing become more ideal at high pressure. But the solvus expands with pressure because entropy approaches ideality faster than enthalpy and, therefore, Gibbs energy of K-Na mixing becomes less ideal with pressure. The consolute temperature rises about 80 °C in 17 kbar, with little change in consolute composition. The binary Margules equation of state provides a prediction of the rise of the solvus that is impressively convergent with the new observations. This convergence is especially impressive given the clear inadequacies of the binary excess volume formulation on which the prediction is based.

The flotation-based separation of the salt minerals sylvite (KCl), halite (NaCl), carnallite (KCl·MgCl2·6H2O) in saturated solutions of electrolytes (KCl–NaCl–H2O and MgCl2–KCl–NaCl–H2O is discussed. The use of special organic polymers and surface-active substances makes it possible to separate, at a high selectivity at normal temperatures, the particles of salt minerals of differing crystalline-chemical properties, by suppressing the negative effects of alumosilicate and carbonate slimes. Requirements are specified to the composition and properties of the flotation reagents depending on the type of potassium- and magnesium-containing ores, conditions of their processing and quality requirements to the end product. New reagents are proposed for flotation of salt minerals and suppression of alumosilicate and carbonate mineral slime impurities. Examples of commercial use of the technologies developed are given.

The Early Devonian Lake George granodiorite stock, New Brunswick, Canada, is spatially and temporally associated with early W‐Mo‐Au and later Au‐Sbmineralization. The former mine was the largest antimony producer in North America until the mid-1990s. On the basis of fluid-inclusion analyses, multiple generations of fluids evidently interacted with the granodiorite, with the dominant fluids approximated by the system H2O‐NaCl‐CO2‐CH4. Additional components of the fluid, S‐Ca‐Fe‐K‐Mg‐ Mn, reflect fluid‐rock reaction and partial re-equilibration among the rock-forming minerals (i.e., plagioclase, orthoclase, biotite, and hornblende) in the granodiorite. The CO2-bearing inclusions (Type 1) have a relatively low salinity, ranging from 0 to 15 wt.% equiv. NaCl (ave. 4 wt.%), and most homogenize to the CO2 phase at temperatures of 200 to 470°C. Inclusions that homogenize to the aqueous phase do so over a narrower range of temperatures (250‐350°C). Fluid pressures were probably 740 to 2210 bars for Type-1 inclusions. Aqueous liquid + vapor (Type 2) and aqueous liquid + vapor + halite or sylvite (Type 3) inclusions are recorded as well. Type-2 inclusions show a broader range of temperatures of homogenization (mostly to the aqueous phase), from 150 to 580°C, with a salinity between 2 and 19 wt.% equiv. NaCl. The stable isotope compositions of the rock-forming minerals in the granodiorite exhibit a disequilibrium relationship, e.g., either � 18 OK-feldspar > � 18 Oquartz, � 18 Oplagioclase > � 18 Oquartz, or � 18 Oplagioclase > � 18 OK-feldspar. The whole-rock � 18 O values range from 9.4 to 10.7‰, consistent with derivation by

The Bayan Obo REE-Nb-Fe deposit hosts the world's largest known REE resource. The deposit consists of replacement bodies hosted in dolomite marble and of magnetite, REE fluorocarbonates, fluorite aegirine, amphibole, calcite, and barite. Three types of fluid inclusions have been recognized: two-phase aqueous liquid-vapor (L-V), two- to three-phase CO2 (C), and three-phase liquid-vapor-solid (L-V-S) inclusions. Microthermometry measurements indicate that the carbonic phase in C inclusions is nearly pure CO2. During heating experiments, hexagonal or irregular-shaped daughter minerals in L-V-S inclusions complete dissolution at temperatures of 420-480°C and recrystallize again at about 400-320°C. These show that daughter minerals in multiphase inclusions in mineralizing veins were crystallized from trapped fluids, and are real daughter minerals. REE-carbonates, halite, sylvite, barite, calcite, and pyroxene (?) have been identified on the basis of crystal habit (microscopic and SEM) and EDX analysis. By comp...

Filatovite, ideally K((Al,Zn)2(As,Si)2O8), has been found in products of fumarolic activity on the second cinder cone of the North breach of the great fissure Tolbachik eruption (1975-76, Kamchatka peninsula, Russia). The mineral occurs as pris- matic crystals up to 0.3 mm and as intergrowths of crystals, in association with alumoklyuchevskite, lammerite, johillerite, sylvite, As-bearing orthoclase, hematite and tenorite. Filatovite is colourless, with vitreous luster and white streak. The mineral is brittle and transparent. It has a good {100} cleavage. Mohs' hardness is 5-6. The calculated density is 2.92 g/cm3. Biaxial, optically nega- tive, ! = 1.532(1), " = 1.535(1), # = 1.537(1), 2Vmeas. = 60(10)°, 2Vcalc. = 78°. Optical orientation: X ~ (100), Y and Z are normal to the {001} and {010} faces, respectively. No pleochroism has been observed. The mineral is monoclinic, space group I2/c, a = 8.772(1), b = 13.370(2), c = 14.690(2) A, " = 115.944(6)°, V = 1549.1(4) A3, Z = 8 (from single-crystal structure study). The diagnostic lines of the X-ray powder diffraction pattern are (I-d-hkl): 70-4.329- $ 202; 70-3.897- $ 130; 100-3.364- $ 220,$ 204, 040; 50-3.300-004, 40-3.066-132, 60-2.981-042, 40-2.646- $ 242. Chemical composition (wt. %): P2O5 1.63, As2O5 40.60, SiO2 12.35, Al2O3 27.33, CuO 0.83, ZnO 3.85, FeO 0.28, Na2O 0.63, K2O 12.85, total 100.35. The empirical formula of filatovite, calculated on the basis of O = 8, is (K0.92Na0.07)% =0.99((Al1.81Zn0.16Cu0.04Fe0.01)% =2.02(As1.20Si0.70P0.08)% =1.98O8). The simplified formula is K((Al,Zn)2(As,Si)2O8). The detailed chemical formula can be written as K((Al2-xZnx)(As1+xSi1-x)O8), with x ~ 0.20. Filatovite is a new mineral of the feldspar group and is structurally related to celsian. The name honors Prof. Stanislav K. Filatov (b. 1940), Department of Crystallography, St. Petersburg State University, St. Petersburg, Russia, for his important contributions to high temperature crystal chemistry and crystal chemistry of exhalation minerals.

This paper describes the salt content and pH evolution in solutions produced by the water-soluble extraction of accumulated pigeon droppings. Results demonstrate that these accumulations contain 4 % of soluble salts. Therefore, they are a plausible source of salts commonly found on buildings. These salts comprise halite, sylvite, potassium calcium sulphate, aphthitalite, apatite group minerals, weddellite and gypsum. The interaction of solutions formed from pigeon droppings with porous limestone was also studied. A noticeable deterioration in limestone due to acid attack was observed, including surface etching of rock-forming minerals.

In the potash production industry, sylvite is selectively floated from halite with the use of cationic collectors. Due to the high solubility of the KCl and NaCl minerals, the process has to be conducted in saturated brines of these salts and at very high collector concentration. The understanding of the mechanisms involved in this peculiar selective flotation process has progressed well in the recent years and is briefly discussed herein. Studies of the effect of the addition of long chain alcohols on the dodecylamine adsorption and flotation of KCl were undertaken and the results are presented. Potassium chloride flotation with dodecylamine was enhanced by the addition of hexyl and octyl alcohol with the best results in the concentration range of from 6 to 8 × 10−3 M. Decyl alcohol had a less effective influence on KCl floatability. The surface tension of dodecylamine solution as a function of KCl concentration and the lowering of the amine critical micelle concentration in KCl saturated solution were also studied and the role of the long chain alcohol addition on the flotation recovery of potassium chloride with dodecylamine is discussed.

Enthalpies of solution of the NH 4 + -bearing minerals buddingtonite (NH 4 AlSi 3 O 8 feldspar) and tobelite [NH 4 Al 2 (AlSi 3 O 10 ) (OH) 2 mica] have been measured in 20.1 wt% hydrofluoric acid (HF) at 50°C. Utilizing additional HF solution calorimetric data from this laboratory for sanidine, albite, muscovite, paragonite, halite, sylvite, salammoniac, gibbsite, and water, along with enthalpies of formation from Robie and Hemingway (1995) for the same phases, the heats of formation at 298.15 K of buddingtonite and tobelite have been determined to be −3883.9 and −5881.3 kJ/mol, respectively. Entropies of ~247 and ~319 J/(mol ·K) for these minerals (298.15 K) have been approximated from various ion-exchange equilibria involving feldspars, micas, and chlorides. Collectively, these data result in 298.15 K Gibbs free energies of formation from the elements of −3579 and −5422 kJ/mol, respectively, for buddingtonite and tobelite, values that differ by 40 to 50 kJ/mol from those given previously by Mader et al. (1996). The calculated phase equilibria that result from the data of this investigation are reasonable relative to the conditions required to synthesize both buddingtonite and tobelite (Harlov et al. 2001b, 2001c).

Unit-cell volumes of four single-phase intermediate halite-sylvite solid solutions have been measured to pressures and temperatures of ~28 kbar and ~700 °C. Equation-of-state fitting of the data yields thermal expansion and compressibility as a function of composition across the chloride series. The variation of the product α 0 · K 0 is linear (ideal) in composition between the accepted values for halite and sylvite. Taken separately, the individual values of α 0 and K 0 are not linear in composition. α 0 shows a maximum near the consolute composition ( X NaCl = 0.64) that exceeds the value for either end-member. There is a corresponding minimum in K 0 . The fact that the α 0 · K 0 product is variable (and incidentally so well behaved as to be linear across the composition series) reinforces the significance of the complementary maxima and minima in α 0 and K 0 (significantly, near the consolute composition). These extrema in α 0 and K 0 provide an example of intermediate properties that do not follow simply from values for the end-members. Cell volumes across this series show small, well-behaved positive excesses, consistent with K-Na substitution causing defects through lattice mismatches. Barrett and Wallace (1954) showed maximum defect concentrations in the consolute region. Defect-riddled, weakened structures in the consolute region are more easily compressed or more easily thermally expanded, providing an explanation for our observed α 0 and K 0 variations. These compliant, loosened lattices should resist diffusive transfer less than non-defective crystals and, hence, might be expected to show higher diffusivities. Tracer diffusion rates are predicted to peak across the consolute region as exchange diffusion rates drop to zero.

The tropospheric dust loading in Upper Silesia (Poland) shows a steady, annually averaged supply of minerals from natural and anthropogenic sources, industrial dust emitters, domestic heating, transportation, but with superimposed seasonal changes for some dust types. Samples of airborne and deposited particles were collected at monthly intervals between 1996 and 2001 in several cities of Upper Silesia. Dust samples were examined by X-ray powder diffraction, analytical transmission electron microscopy, analytical scanning electron microscopy, and electron microprobe microanalysis. The most common dust included quartz, gypsum, coke, soot, hematite, magnetite, wüstite, bassanite, graphite and various K-, Fe- and Mg-bearing aluminosilicates, in order of decreasing abundance. Minor phases included α-iron, sulphur, sphalerite, halite, sylvite, hercynite, franklinite, baryte, dolomite, ankerite, apatite, olivine and feldspars. Quartz, and specific industrial minerals, e.g. spinels, sphalerite, olivine and iron, occurred throughout the year in almost constant abundances. The amounts of all other dust components show seasonal variations; gypsum, baryte and other sulphates are particularly abundant in winter. In general, minerals related to low-emission sources are abundant in the winter time, while both natural dusts and dust from high-emission sources are predominant during the summer.

A MSWI fly ash was characterized with respect to leaching properties (pH-static leaching, availability test), mineralogy (X-ray powder diffraction (XRPD)), and morphology and element distribution (scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX)) before and after electrodialytic treatment to study possible changes in the ash characteristics due to the treatment. It was shown that although a significant amount of the initially present heavy metals had been removed from the ash during the electrodialytic treatment, the leachability of several of the residual metals had actually increased, presumably due to mineral dissolution and chelating of metals by residual citrate in the ash. Ammonium citrate had been added to the ash before and during electrodialytic treatment to increase the heavy metal desorption. The morphology and mineralogy of the ash was also altered as a result of the treatment. XRPD examinations showed that a depletion of Cl, Na and K in the treated ash was due to wash-out of the highly soluble minerals sylvite (KCl) and halite (NaCl). Indications of formation of secondary minerals (Ca-sulphates, ettringite) and precipitation of Ca-citrate in the treated ash were also seen. SEM investigations confirmed a changed morphology in the treated ash; probably due to the formation of secondary minerals.

Some physicochemical (insoluble content, ionic composition, density, and X-ray diffraction spectra) characteristics of Nigerien evaporites were investigated in this study. The results obtained showed that trona is the main mineral contained in Agadez, Dirkou, Niamey, and Zinder evaporites while thenardite and halite constitute the major minerals in Bilma and Tabalak evaporites, respectively. In addition, all evaporites samples investigated revealed the presence of quartz and halite. Other interesting minerals (calcite, gypsum, sylvite, aphthitalite, nahcolite, illite, burkeite, kaolinite, griceite, and talc) were also detected. The use of Agadez, Dirkou, Niamey, and Zinder evaporites as catalyst to accelerate cowpea cooking is due to bicarbonates ions present in trona. Bilma and Tabalak evaporites employed in animal feeding are due to the halite contained in a significant quantity.

The Bismark deposit (8.5 Mt at 8% Zn, 0.5% Pb, 0.2% Cu, and 50 g/t Ag) located in northern Mexico is an example of a stock-contact skarn end member of a continuum of deposit types collectively called high-temperature, carbonate-replacement deposits. The deposit is hosted by massive sulfide within altered limestone adjacent to the Bismark quartz monzonite stock (~42 Ma) and the Bismark fault. Alteration concurrently developed in both the intrusion and limestone. The former contains early potassic alteration comprising K-feldspar and biotite, which was overprinted by kaolinite-rich veins and alteration and later quartz, sericite, and pyrite with minor sphalerite and chalcopyrite. Prograde exoskarn alteration in the limestone consists of green andradite and diopside, and transitional skarn comprising red-brown andradite, green hedenbergite and minor vesuvinite, calcite, fluorite, and quartz. The main ore stage post-dates calc-silicate minerals and comprises sphalerite and galena with gangue pyrite, pyrrhotite, calcite, fluorite, and quartz. The entire hydrothermal system developed synchronously with faulting. Fluid inclusion studies reveal several distinct temporal, compositional, and thermal populations in pre-, syn- and post-ore quartz, fluorite, and calcite. The earliest primary fluid inclusions are coexisting vapor-rich (type 2A) and halite-bearing (type 3A; type 3B contain sylvite) brine inclusions (32 to >60 total wt% salts) that occur in pre-ore fluorite. Trapping temperatures are estimated to have been in excess of 400 °C under lithostatic pressures of ~450 bar (~1.5 km depth). Primary fluid inclusions trapped in syn-ore quartz display critical to near critical behavior (type 1C), have moderate salinity (8.4 to 10.9 wt% NaCl equiv.) and homogenization temperatures (Th) ranging from 351 to 438 °C. Liquid-rich type 1A and 1B (calcite-bearing) inclusions occur as primary to secondary inclusions predominantly in fluorite and show a range in Th (104–336 °C) and salinity (2.7–11.8 wt% NaCl equiv.), which at the higher Th and salinity ranges overlap with type 1C inclusions. Oxygen isotope analysis was carried out on garnet, quartz, and calcite (plus carbon isotopes) in pre-, syn-, post-ore, and peripheral veins. Pre-ore skarn related garnets have a δ18Omineral range between 3.9 and 8.4‰. Quartz from the main ore stage range between 13.6 and 16.0‰. Calcite from the main ore stage has δ13C values of –2.9 to –5.1‰ and δ18O values of 12.3 to 14.1‰, which are clearly distinct from post-ore veins and peripheral prospects that have much higher δ18O (16.6–27.3‰) and δ13C (1.3–3.1‰) values. Despite the numerous fluid inclusion types, only two fluid sources can be inferred, namely a magmatic fluid and an external fluid that equilibrated with limestone. Furthermore, isotopic data does not indicate any significant mixing between the two fluids, although fluid inclusion data may be interpreted otherwise. Thus, the various fluid types were likely to have formed from varying pressure–temperature conditions through faulting during exsolution of magmatic fluids. Late-stage hydrothermal fluid activity was dominated by the non-magmatic fluids and was post-ore.

The Okorusu fluorite deposit occurs in Pan-African carbonaceous rocks of the Damara Sequence in northern Namibia. The epigenetic mineralization formed from fluids expelled from the Cretaceous Okorusu carbonatite, which is part of the Damaraland igneous province related to the South Atlantic oceanic opening. The fluorites contain abundant high-field-strength elements (∑REE=80–285 ppm, Sr=1900–2500 ppm, Y=8–50 ppm). They have 87 Sr/ 86 Sr 127 Ma values of 0.70458–0.70459, which are close to those of the Okorusu carbonatite. Primary and secondary aqueous fluid inclusions in the fluorites contain 3 wt.% NaCl equiv. at most, and homogenization temperatures are around 120 °C. The immediate country rocks of the fluorite mineralization contain a highly varied H 2 O–CO 2 fluid-inclusion population trapped in quartz which we, based on their distribution and composition, consider to represent an orthomagmatic fluid responsible for the fluorite mineralization. Cathodoluminescence imaging of the quartz delineates the pathways for carbonatitic fluid movement and suggests a single fluid infiltration event. The fluid was trapped under conditions of extreme heterogeneity to form an inclusion population consisting of all volumetric proportions between an aqueous brine, a CH 4 -bearing CO 2 phase and solid phases. Based on energy-dispersive X-ray analysis of opened inclusions and laser Raman spectrometry of unopened inclusions, the following solid phases have been identified: halite, sylvite, nahcolite, K-feldspar, a Ba,Ca oxide/hydroxide, possibly zharchikite AlF(OH) 2 , an LREE hydroxide/fluoride (?), galena and cerussite, fluorapatite, cryolite, burbankite, pyrite, fluorite, barite and kyanite (?), amongst others. Crush–leach analysis applied to the inclusion-bearing quartz yielded 87 Rb/ 86 Sr=0.15059 and 87 Sr/ 86 Sr=0.70495 for the fluid leachate, 87 Rb/ 86 Sr=0.65141 and 87 Sr/ 86 Sr=0.70551 for the residual quartz, and 87 Rb/ 86 Sr=0.22752 and 87 Sr/ 86 Sr=0.70501 for the bulk quartz (all values calculated for T =127 Ma). The regression line for these data points represents a mixing line between the Damaran host rock and a Cretaceous fluid. At 87 Rb/ 86 Sr=0, the regression line yields 87 Sr/ 86 Sr 127 Ma =0.70478, which is only slightly more radiogenic than recorded for the fluorites and associated Okorusu carbonatite. Crush analysis of the bulk quartz and normalization of the raw data to 100 wt.% at CO 2 =20 wt.% and H 2 O=20 wt.%, yielded the following chemical composition for the carbonatitic fluid: Na 2 O=21.1 wt.%, K 2 O=8.0 wt.%, CaO=5.5 wt.%, FeO (total)=3.2 wt.%, F=3.0 wt.%, Cl=10.8 wt.%, ∑REE=3 wt.%, Ba=32,754 ppm, Sr=11,484 ppm, Zr=137 ppm, Y=462 ppm, Th=444, U=15.9 ppm and Pb=1260 ppm. It is concluded that the trapped fluid-inclusion population represents a sample of the carbonatitic fluid with only minor crustal contamination, which reacted with crustal carbonate rocks to precipitate fluorite. The characteristic features of this fluid are its high-alkali and comparably low-Ca contents resulting in (Na+K)/Ca=5.7, a high F content (Cl/F=3.6) and high-field-strength element concentrations in the percentage range. As a consequence, we infer that the low-temperature and low-salinity inclusions in fluorite are unlikely to represent the fluids responsible for the primary mineralization for carbonatite-associated fluorite deposits, as exemplified by the Okorusu samples.