Search

Density and thermal expansion measurements have been performed for liquid caesium and caesium–bismuth alloys (20–66.7 at.% Bi) in the temperature range from the liquidus curve to 1000 K. A gamma-ra...

Leaching of tellurium from tellurium-bearing materials is of significant importance. A novel alkaline sulphide leaching process for tellurium-bearing materials was developed. It was found t...

The construction of geological and geotechnical models in typical Pilbara iron ore environments is vital to enable an optimized mine design for the life of the asset, while maintaining pit wall integrity and overall mine safety. Geotechnical assessments require the measurement of geomechanical properties, such as the triaxial shear, direct shear and unconfined compressive strength tests and pressure and shear wave velocities on diamond core samples. Ideally, these velocities would be measured in Reverse Circulation (RC) boreholes as their spatial density is far higher than diamond drilled holes. Unfortunately, despite its value, such data is seldom collected as a large proportion of the holes are above the water table, limiting the use of sonic-logging tools. Even if measurements are possible, damage to the borehole caused by drilling biases the resulting velocity measurements. This paper details the results of a trial using the vertical seismic profile method to directly measure in-situ seismic velocities in RC boreholes. The method was successful in determining the velocities of the formations through the entire length of the holes. The data in several boreholes was of sufficient quality for the application of more advanced processing methods, important for geological mapping and the processing and interpretation of surface seismic data. The success of this first trial has implications for future iron-ore developments in the Pilbara. The widespread acquisition of accurate seismic velocity data is likely to enable the creation of more accurate geotechnical models and could improve future development decisions.

Hydraulic fracturing in many Australian Basins, particularly the Cooper Basin has been successful in higher permeability, structured conventional plays. However, adaptation of North American strategies to Australia’s complex, and highly stressed unconventional areas has resulted in less than adequate performance to progress further investment into widespread development these resources. This presentation will explore the obvious differences between Australian and North American stress settings, and the problems manifested by those differences in hydraulic fracture containment and behaviour. Further, as more unconventional targets are attempted, complementary strategies need to be considered based on fundamental geomechanical principles, relative to these basinal environments. This presentation will explore several problems, emerging potential solutions, and areas of ongoing research with the purpose of aiding Australia to tap into a vast supply of potential unconventional resources, which are currently under-appraised.

Dry bulk density is a key parameter in resource estimation and mine and process planning. Ore bodies are mapped as volumes, whereas mineralisation grade is reported as mass fractions, requiring rock density to complete the reserves calculation. Similarly, although a volume of rock is to be excavated, planning for the transport and processing of this material takes place in terms of the mass of ore to be handled, again requiring rock density information to convert between the two. Although many different densities can be defined based on the underlying mass and volume definitions, the one of most interest to the mining industry is dry bulk density, or the dry mass per unit volume of in-situ rock. This contrasts with the in-situ bulk density, which includes the mass of any fluids in the pore space of the rock. In-situ bulk density can be accurately measured using borehole geophysical techniques, but no direct downhole measurement of dry bulk density is possible. Therefore, common practice is to determine mass, after drying, and volume of core samples for calculation of dry bulk density. However, this process can be time consuming and problematic with porous or unconsolidated samples. Another approach to estimate dry bulk density, amenable to downhole application and therefore avoiding many of the complications related to core measurements, utilises in-situ bulk density and magnetic resonance porosity measurements. Combining these two measurements allows for continuous dry bulk density evaluation without the need for coring.

Cassiterite and rutile strongly resist physical and chemical weathering and can be used as indicator minerals for mineralisation. These minerals are residually concentrated in a near-surface silcrete duricrust capping a deeply weathered profile developed over the Scuddles Cu-Zn-Pb VMS deposit, Golden Grove, Western Australia. These minerals were extracted by panning of rock chips from Reverse Circulation drill holes and studied by optical, scanning electron microscopy and mapped and analysed by electron probe. The formation of silcrete involved destruction of all labile minerals, removal of clays and leaching of alkali, alkaline earth and transition (e.g. Fe, Mn, V, Ni, Co, Cu, Zn) elements. This is followed by residual concentration of high field strength elements in resistate minerals and silica cementation. The main driving force in the formation of silcrete is the oxidation of massive sulphides generating strongly acidic and highly saline fluids. Under these conditions, silica was probably transported as either silicic acid from destabilising aluminosilicates or as an aqueous sol under neutral to low pH conditions. In addition, Au and Ag were remobilised from the massive sulphide mineralisation as a halide complex. Cassiterite, rutile and quartz in silcrete contain inclusions of pyrite, chalcopyrite, sphalerite, galena and argentite identical to those in the underlying VMS. Thus, they are considered as indicator minerals for VMS exploration. Bioturbation and organic acids produced by decay of plants from the upper lateritic profile remobilised clays downward as colloid, recycled Au from Ag halides and attacked resistant heavy minerals. Oxidation of sulphide inclusions in cassiterite, rutile and quartz intensely corroded these minerals and liberated trace elements (i.e., Sn, Ti, Pb, Sb, Bi, Hg, Se, Ge, W, Mo and Te) to form cements of complex chemical compositions. These cements and Au-Ag halides form a multi-element anomaly in silcrete delineating the underlying VMS deposits at Scuddles.

The present paper investigated the separation performance of tri-cone water medium cyclone and conducted simulation studies on flow field inside cyclone by ANSYS FLUENT, by comparison with that of ...

The melting rate of round and square steel bars with various initial temperatures and sizes, and steel bars immersed in a liquid steel bath with different temperatures were studied. A steel shell w...

The suitability of the organophosphorus-based extractants, DiOPA, Ionquest 801 and D2EHPA was evaluated for the selective extraction of Zr and Hf from an (NH4)3Zr(Hf)F7 acidic solution using both d...

By October 2018, there are 35 copper smelters under operation in China, with an annual output of 9860 kt refined copper. In copper matte converting, P-S converters are still used in 20 copper smelt...

Size-by-size performance analysis has been carried out for a 300 tph Leebar dense media bath cleaning met coal. Feed size distribution and feed density distribution both have a considerable effect ...

Horizontal Single Belt Casting is by far the simplest of all near net shape casting machines and is ideally suited to replace current slab caster operations, given its matching productivity, ‘green...

Converter steelmaking is the main stage in ore-based production using blast furnace hot metal and steel scrap as charge materials. Over 70% of steel is produced via basic oxygen converters today. The converter process was developed in the middle of nineteenth century by blowing air through pig iron melt for decarburisation. The subsequent innovation was basic lining and the Thomas process. The next problem, the switch from air to oxygen was hard and did not succeed on an industrial scale until the 1950s when oxygen blowing via top lance was developed. Oxygen bottom blowing was then solved by applying annular nozzles with hydrocarbon cooling. Current technologies combine benefits of top and bottom blowing in hybrid processes. In this review, the history of converter processes is briefly surveyed. Recent progress and challenges, e.g. better utilisation of post combustion for scrap melting, are discussed. Continuous converting and the future role of converter process are also highlighted.

In this paper, an elastic-plastic damage model is first proposed for a class of semi-brittle rocks. This model is then applied to investigate effects of chemical degradation on mechanical behavior ...

This study investigated the adsorption of calcium and gypsum on scheelite and fluorite using micro-flotation, X-ray photoelectron spectroscopy, scanning electron microscope with energy-dispersive s...

In this study, the −1 mm fine coal is treated in a laboratory Knelson concentrator. The influence of various parameters (e.g., feed rate, solid content, centrifugal force, and the fluidization wate...

In order to research the influence of high-sulfate mine water on filling paste, the macroscopic and microstructural changes of the filling paste in the sulfate environment were analyzed by uniaxial...

The utilisation of limonite ore is potentially important to China as the high quality iron resource, such as magnetite and hematite of high grade, are rapidly depleting, but many detrimental impurities, such quartz and calcite etc, are difficult to upgrade to make suitable concentrates for the blast furnace. The flotation behaviour of limonite, quartz and their mixture by using sodium oleate as collector were studied systematically in this paper. Single-mineral flotation tests showed that the flotation recovery of limonite was much higher than that of quartz in a broad range of pH. However, flotation tests for the mixture of limonite and quartz showed rather poor mineral separation efficiency with the flotation recovery of both minerals being high in froth products. The flotation separation efficiency of limonite from quartz was substantially improved by adding sodium hexametaphosphate (SHMP) as a depressant for quartz flotation. To elucidate these phenomena, the solution species calculation of limonite dissolution and the measurements of iron ions content were carried out. It was found that iron ions or its species released into the pulp from the dissolving of limonite could effectively activate the flotation of quartz but have little influence on the flotation of limonite. In the presence of SHMP, iron ions or its species lost their activating power on quartz flotation which caused by the chemical reaction between SHMP and iron ions or its species, and then removed iron ions or its species from quartz surface into the solution.

In this review, resources of nickel and status of different processes/technologies in vogue or being developed for extraction of nickel and associated metals from both primary and secondary resourc...

Skorpionite, Ca3Zn2(PO4)2CO3(OH)2·H2O, forms acicular, vitreous, colorless monoclinic crystals a few millimeters long and seldom more than several millimeters in length (fig. 1). These are elongate...

The definition of the search neighbourhood in kriging can have a significant impact on the resulting estimates. Stationary domains are usually estimated using a unique search strategy for the entir...

This study proposes a design guideline for polycrystal Ni-based model alloys with high ductility and 100-MPa creep rupture strength beyond 800°C and 105 h. These alloys are strengthened by ...

In this study wet grinding batch experiments were performed in a laboratory ball mill using laterites from Evia island, Greece, in order to determine the optimal grinding conditions for potential n...

In order to compact coal logs which could be transported smoothly in the hydraulic pipeline, the polyvinyl alcohol was used as the binder and mixed with anthracite, bituminous coal and lignite, res...

Corrosive surface degradation of equipment is one of the main problems in the oil and natural gas industries. It occurs mainly as a result of contamination by corrosive and/or abrasive materials th...

The respirable dust generated during bolt-hole drilling can present serious health problems to the miners involved in roof drilling operations. A proactive dust control approach, different from the conventional passive approaches, is proposed. Laboratory experiments have been conducted to validate the dust reduction effects of the approach. A mechanical model has been developed to simulate the rotary drag bits drilling process under different cutter conditions. The functions of the area of the total friction, drilling power, and specific energy are all presented in the model. According to this model, drilling bite depth and bit wear condition were identified as key factors influencing the respirable dust generation and energy consumption. The relationships among drilling specific energy, airborne dust concentrations of respirable and larger (1-100 μm) particles, and drilling bite depth were established. It was found that by achieving a low specific energy with a proper drilling bite depth and by avoiding worn bit use, a significant reduction of quartz-rich respirable dust from its generation source could be achieved. Once validated, the mechanical model can be used for roof bolter drilling optimization and automation control.

The effects of configuration of the stirred tank and energy input on the flotation performance of nickel ores were systematically investigated in this paper. Flotation tests revealed that the stirr...

Trough profile is an important structural parameter of the spiral concentrator. However, limited attention has been focused on the influence of trough profile on coal separation. In the present wor...

This study investigates the inclusions, microstructure, tensile properties, and impact toughness of reduced activation ferritic/martensitic (RAFM) steels with different Y contents (0.006, 0.034 and 0.071 wt-%). Owing to the pinning of the grain boundary to the Y inclusions (which refines the original austenite grain size) and an existing Fe–Cr–Ta–Y–S–O phase, the tensile strength at both room and high temperatures increased with increasing Y content (below 0.071%). Increasing the Y content to 0.034 wt-% decreased the ductile-to-brittle transition temperature (DBTT). However, when the Y content reached 0.071 wt-%, the DBTT increased as the Y precipitated into blocky yttrium-rich inclusions. The microstructure, tensile properties, and impact toughness of the RAFM steel were optimised at a Y content of approximately 0.034 wt-%.

The sintering behaviour of ore fines under different Al2O3 content and different alkalinity was studied by DSC–TG method. The reaction kinetics of the sintering process was calculated. Simultaneous...

Automation of the iron and steelmaking operations is an inevitable task to improve quality and to minimise cost. Recent studies showed that vibroacoustic-based monitoring techniques can be used to ...

The quantity and accuracy of fundamental data available on copper smelting and converting systems has greatly increased over the past several decades. Engineers need no longer rely on approximations and interpolation of chemical behaviour from idealised or simplified low-order systems. Sophisticated thermodynamic databases and dedicated thermodynamic computer platforms make it possible to predict the outcomes of complex multicomponent, multiphase reactions, and to present this information in forms that are useful for industrial practice. In the present paper a summary and review of phase equilibria data on key Cu-Fe-O-S sub-systems including Ca, Si and minor elements, is provided, as are examples of the application of thermodynamic and thermochemical calculations to the modelling of copper converting. As further information on chemical behaviour and integration with process models become available these sophisticated predictive tools and approaches will become increasingly used to improve metallur...

The phosphates of rare earth (RE) metals are highly stable in natural environment, and RE oxides have higher optical basicity than CaO and BaO. Therefore, the thermodynamic conditions for dephosphorisation using RE oxide-containing slags are expected to be favourable. Factors influencing the efficiency and Mn loss during the dephosphorisation of ferromanganese using RE oxide-containing slags were studied. An increase in the dephosphorisation temperature up to 1673 K (1400°C) is beneficial to the process and decreases Mn loss, and the maximum degree of dephosphorisation for slags containing 6 wt% RE oxides are 47.44 and 50.85%, corresponding to the minimum values of Mn loss are 1.64 and 1.35% at 1673 K (1400°C); further temperature increases would deteriorate the dephosphorisation efficiency and lead to an obvious increase in Mn loss. An increase in the quantity of pre-melted slags, and of their RE oxide content, improves the dephosphorisation efficiency but inevitably leads to a more pronounced Mn...

Pulsating bottom-blowing was proposed to strengthen the electric arc furnace (EAF) molten bath stirring. The fluid flow characteristics and stirring effects of different pulsating bottom-blowing modes on EAF molten bath were studied through water model experiments and numerical simulations. The mixing time was measured by water model experiments and the flow field characteristics of EAF molten bath were simulated by numerical simulations. Compared with conventional bottom-blowing, pulsating bottom-blowing can accelerate the fluid flow velocity and improve the stirring of molten bath. With pulsating bottom-blowing, the molten bath fluid flow field is more disorder, the fluid flow velocity increases and the dead zone volume decreases. Compared with EAF steelmaking with conventional bottom-blowing conditions, pulsating bottom-blowing technology can improve the metallurgical effects and the molten steel quality in EAF steelmaking with lower FeO content of final slag, lower phosphorus content and carbo...

Flotation performance is expected to be affected by froth characteristics due to the changes in the operating conditions. However, very little study has been undertaken to investigate how froth beh...

The surface oxidation weight gains on 7.8 wt% Cr-containing stainless steel at different temperatures were studied by thermogravimetric analysis and scanning electron microscope (SEM) equipped with...

Separation of platinum and palladium, using solvent-impregnated resin (SIR) impregnating di-hexylamine (DHA), di-n-octylamine (DOA), or di-hexyl sulfide (DHS), coated by polyvinyl alcohol crosslink...

Flotation is one of the feasible separation methods suggested for recovery of petroleum coke from the tailings of lime calcination furnaces. In this study, analyses of ash content and calorific val...

The extent of coal cleaning is primarily dependent upon three core factors; (1) coal liberation, (2) coal washability, and (3) separator performance. The first factor has been dealt with in part 1....

Energy is of great theoretical and practical importance in flotation. Some progress has been achieved in recent years. However, the study of energy consumed in the flotation process is still not fu...

To elucidate the morphology evolution of the inclusions in 16MnCrS5 steel with various masses of Mg addition, the experiments and thermodynamics were carried out with a high-temperature tube electric resistance furnace and FactSage software, respectively. The evolutions of the inclusions after the smelting and hot-processing were described. The experimental results show that with Mg addition of 35–42 ppm, many spindle and spherical inclusions with the size below 20 μm appeared, whereas the long-strip inclusions above 20 μm disappeared; after hot-processing, particularly, the h value was above 50%, beneficial to obtaining more spindle inclusions, and most spherical inclusions at 35 ppm were also obtained. The thermodynamics show that with Mg mass between 0.349 and 6.076 ppm, Al2O3 was easily converted to MgO·Al2O3, whereas above 6.076 ppm, Mg was directly converted to form MgO; above more, MgS coexisted with MgO.

Investigations were carried out to use Granulated Blast furnace (GBF) slag as mould material for either full or partial replacement of existing silica sand in foundry industry. Nishiyama process was adopted for evaluating the same. A series of sand tests were carried out on sand and slag individually and also combinations of these two. Three types of moulds were made with sand, slag individually and combination of these two. Both laboratory and industrial castings of ferrous and non ferrous materials were performed. Results of mould permeability, compression and shear strength of GBF slag reveal that is a suitable candidate for either partial or full replacement of molding sand. During casting of both laboratory and industrial, neither fuse, dripping nor collapse of the mould walls was observed; this is true for both ferrous and non ferrous castings. Castings with good surface finish, no surface defects and porosity were made by slag moulds.

Scheelite could be digested with an aqueous diammonium phosphate and ammonia solution in an autoclave. However, unexpected ammonium paratungstate (APT) crystallisation and tungstophosphoric...

Studies on the recovery of tungsten and molybdenum from refractory scheelite–powellite blend concentrates – mainly composed of scheelite, powellite, and fluorite – were performed using soda-silicon...

Lining spalling can occur in metallurgical vessels since their working linings experience intense thermomechanical loads in service. It is necessary to consider the spalling phenomenon in t...

In this work, the oxidation properties of low-iron vanadium-titanium magnetite with high vanadium and titanium in a laboratory muffle furnace was investigated. XRD, SEM, and TG-DSC method are emplo...

In general, the washing of coal is greatly influenced by the amount of near-gravity material (NGM) present at the desired cut density. It is observed that the presence of a high percentage of NGM coal results in significant misplacement of particles to wrong products and reduces the separation efficiency of dense medium cyclone (DMC). In this work, an attempt is made to study the behavior of different sizes of NGM coal particles at three feed relative densities inside 350 mm DMC using a discrete phase model (DPM) superimposed on the magnetite medium segregation simulated by modified mixture model. The Reynolds stress model (RSM) is used to resolve turbulence. The DPM is adopted to track different sizes and densities of coal particles, and then a partition curve is constructed to calculate the Ecart probable (Ep) error, percent misplacement, and imperfection. The results show that the lighter and heavier density coal particles away from the separation cut density exhibit very short residence times. Fine-sized coal particles close to the cut density have a significant misplacement compared to the coarse-sized particles having the same density. It is also observed that NGM coal particles show very long residence times irrespective of size.

The extraction of vanadium from the V-Cr-bearing reduced residue formed from the waste water by reduction and neutralization in the process of extracting vanadium from vanadium slag was inv...