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The kinetic study of the ozonation of atrazine as a single contaminant characterized as COD was studied. A jet loop ejector reactor was used to improve the mixing and transfer of ozone in the reaction system. The results show a higher efficiency of atrazine degradation in alkaline pH during the first 45 minutes. At the same time, the dechlorination of atrazine is faster than in neutral pH. Respirometric measurements carried out with activated sludge were used to evaluate the effect of atrazine and the ozonation intermediates on microorganisms’ oxygen uptake rate. The results showed that ozonation performed at an alkaline pH resulted in the formation of substances that are more rapidly biodegradable compared to substances formed by ozonation at neutral pH, as well as compared to atrazine. This work is licensed under a Creative Commons Attribution 4.0 International License.

Arsenic contamination of water resources, which is characterized by strong carcinogenic and toxic impacts, is a global problem. Therefore, the present study is focused on the isotherm and kinetic studies of pentavalent arsenic As(V) adsorption with initial concentration of 1 000 µg L−1 from aqueous solutions onto granular ferric oxide (GFO). Adsorption experiments were carried out by batch method, and the equilibrium and kinetic data were evaluated by the Langmuir, Freundlich, Dubinin-Radushkevich, Redlich-Peterson and Sips isotherm model, and pseudo-first and pseudo-second order kinetic model. The results obtained from this study imply that the adsorption of As(V) onto GFO was favourable, physical and multilayer process. The Sips and Redlich-Peterson isotherm and the pseudo-first order kinetic model gave the best fit to experimental data according to the values of correlation coefficient. The maximum theoretical adsorption capacity from Langmuir isotherm model was determined to be 1 900 µg g−1. In addition, the impact of different operating conditions such as As(V) initial concentration, adsorbent dose, agitation speed, pH, temperature, and presence of phosphates and silica on adsorption capacity of GFO was also investigated. As(V) was efficiently recovered from GFO by 0.1 M NaOH desorbing solution during the three adsorption-desorption cycles. This work is licensed under a Creative Commons Attribution 4.0 International License.

The properties and applications of Au are discussed and price trends from 2001 considered. The processing of Au-containing sulphide, non- sulphide and low-grade ores is described in relation to their mineralogical properties. Legislation relating to health and safety and the environment is considered in relation to processing operations and the storage and disposal of harmful waste., The properties and applications of Au are discussed and price trends from 2001 considered. The processing of Au-containing sulphide, non- sulphide and low-grade ores is described in relation to their mineralogical properties. Legislation relating to health and safety and the environment is considered in relation to processing operations and the storage and disposal of harmful waste.

A review is presented of the origins and locations of bentonite deposits and mineralogical and chemical characteristics of selected samples are considered in relation to useful components such as montmorillonite. The principal physical, physico-chemical and technological properties are described together with possible applications. Current processing methods for the raw materials are reviewed including grinding, milling, sorting, flotation and drying., A review is presented of the origins and locations of bentonite deposits and mineralogical and chemical characteristics of selected samples are considered in relation to useful components such as montmorillonite. The principal physical, physico-chemical and technological properties are described together with possible applications. Current processing methods for the raw materials are reviewed including grinding, milling, sorting, flotation and drying.

Details are given of the occurrence and characteristics of magnesite and magnesite rock. The chemical and mineral compositions of selected samples are described in relation to an evaluation of the quality of Slovak magnesites for use in traditional and new applications. The production of sorbents and of Mg and Mg compounds for various industrial applications is considered with reference to technological and ecological issues and the competition in European and world markets., Details are given of the occurrence and characteristics of magnesite and magnesite rock. The chemical and mineral compositions of selected samples are described in relation to an evaluation of the quality of Slovak magnesites for use in traditional and new applications. The production of sorbents and of Mg and Mg compounds for various industrial applications is considered with reference to technological and ecological issues and the competition in European and world markets.

The occurrence and applications of talc in Slovakia are reviewed and the results of petrographic, mineralogical and chemical analyses are presented. The technological characteristics and by-products of the flotation of talcose rocks are described. Traditional and new applications of both high- and low-quality talc products are considered., The occurrence and applications of talc in Slovakia are reviewed and the results of petrographic, mineralogical and chemical analyses are presented. The technological characteristics and by-products of the flotation of talcose rocks are described. Traditional and new applications of both high- and low-quality talc products are considered.

The artificial carbonatisation of materials containing CaO, MgO or FeO (besides other oxides, non-reactive with CO2) by reaction of their fine-grained grist with suspension of CO2 plus water at appropriate reaction conditions can contribute to stable liquidation of CO2, as well as to liquidation of some environmentally harmful components from these materials, and optimisation of pH in the storage dumps. The carbonatisation results of industrial waste - chromium-magnesium brick from the linings of furnaces (MT) are compared with the sequestration (carbonatisation) potential of natural material: talc-chlorite schist from Gemerska Poloma, metabasic rock from Nizny Klatov, Gelnica chloritic schists and Slanec pyroxenic andesite. For practical reasons, the tested rock types occur in large quantities in nature or are available as a by-product of already existing exploitation activities. The waste sample MT has a high carbonatisation potential of 83.2% producing 73.5% hydromagnesite and 1.1% CaCO3 which can bound 28.2% CO2. 1.757 tonne of MT material is required for the liquidation of 1 t CO2. Of the rock samples, the best carbonatisation results were obtained with the talc-chlorite sample of Gemerska Poloma which produced 86.6% hydromagnesite, in which structure 32.6% CO2 was fixed with a weight yield increase of 5.44% compound product. The Gelnica chloritic schists showed the worst carbonatisation potential., The artificial carbonatisation of materials containing CaO, MgO or FeO (besides other oxides, non-reactive with CO2) by reaction of their fine-grained grist with suspension of CO2 plus water at appropriate reaction conditions can contribute to stable liquidation of CO2, as well as to liquidation of some environmentally harmful components from these materials, and optimisation of pH in the storage dumps. The carbonatisation results of industrial waste - chromium-magnesium brick from the linings of furnaces (MT) are compared with the sequestration (carbonatisation) potential of natural material: talc-chlorite schist from Gemerska Poloma, metabasic rock from Nizny Klatov, Gelnica chloritic schists and Slanec pyroxenic andesite. For practical reasons, the tested rock types occur in large quantities in nature or are available as a by-product of already existing exploitation activities. The waste sample MT has a high carbonatisation potential of 83.2% producing 73.5% hydromagnesite and 1.1% CaCO3 which can bound 28.2% CO2. 1.757 tonne of MT material is required for the liquidation of 1 t CO2. Of the rock samples, the best carbonatisation results were obtained with the talc-chlorite sample of Gemerska Poloma which produced 86.6% hydromagnesite, in which structure 32.6% CO2 was fixed with a weight yield increase of 5.44% compound product. The Gelnica chloritic schists showed the worst carbonatisation potential.

CO2 sequestration by artificial carbonatisation in a high-pressure reactor using appropriate minerals, rocks or waste materials provides a method of permanently binding the CO2 as carbonates. Laboratory tests were carried out to investigate the carbonitisation of two types of material, magnesite waste from the Jelsava plant and serpentinite from the Hodkovce outcrop in Slovakia. The magnesite waste sample contained 84.9% brucite, with 58.7% of the MgO bound in the brucite lattice, and 4.8% portlandite, with 3.62% free CaO in the lattice, both of which are suitable for reaction with CO2. The sample also contained 5.3% maghemite and 2.5% Si and Al oxides which are not appropriate for artificial carbonatisation. The carbonatised product contained hydromagnesite, brucite, calcite, maghemite, brugnatellite and an amorphous phase, with CO2 bound mainly in the lattices of hydromagnesite and to a lesser extent brugnatellite. The CO2 value of the product increased by 21.9% compared with the raw material. The serpentinite contained 81.1% lizardite together with olivine, both important minerals for CO2 sequestration, and a product containing 93.6% hydromagnesite could be obtained after carbonatisation in which CO2 was stable and securely bound in the lattice of the Mg carbonate mineral formed., CO2 sequestration by artificial carbonatisation in a high-pressure reactor using appropriate minerals, rocks or waste materials provides a method of permanently binding the CO2 as carbonates. Laboratory tests were carried out to investigate the carbonitisation of two types of material, magnesite waste from the Jelsava plant and serpentinite from the Hodkovce outcrop in Slovakia. The magnesite waste sample contained 84.9% brucite, with 58.7% of the MgO bound in the brucite lattice, and 4.8% portlandite, with 3.62% free CaO in the lattice, both of which are suitable for reaction with CO2. The sample also contained 5.3% maghemite and 2.5% Si and Al oxides which are not appropriate for artificial carbonatisation. The carbonatised product contained hydromagnesite, brucite, calcite, maghemite, brugnatellite and an amorphous phase, with CO2 bound mainly in the lattices of hydromagnesite and to a lesser extent brugnatellite. The CO2 value of the product increased by 21.9% compared with the raw material. The serpentinite contained 81.1% lizardite together with olivine, both important minerals for CO2 sequestration, and a product containing 93.6% hydromagnesite could be obtained after carbonatisation in which CO2 was stable and securely bound in the lattice of the Mg carbonate mineral formed.

The relationship was investigated between the degree of regional metamorphism and the mineralogical composition and processing of graphite-bearing metamorphic rocks. Samples from a number of deposits in Slovakia were studied representing high-temperature catazonal, medium-temperature mesozonal and low-temperature epizonal metamorphism. The samples were subjected to crushing, sorting, grinding and flotation. The best results were obtained for graphite-bearing high-grade metamorphic rocks such as those from Muran and Kokava nad Rimavicou. The graphite contents of flotation concentrates were in the range 67-77% with enrichment factors of 19-24 for the highly crystalline graphite. Poor results were obtained with the epizonal graphite-bearing rocks such as those from the Male Karpaty and Spis-Kermer mountains, with the graphite contents in the concentrates being 20.1-27.9% with enrichment factors of only 4.8-6.5 for the more amorphous graphite. The results confirm that higher metamorphic temperatures increase the crystallinity of the graphite, leading to improved processing characteristics., The relationship was investigated between the degree of regional metamorphism and the mineralogical composition and processing of graphite-bearing metamorphic rocks. Samples from a number of deposits in Slovakia were studied representing high-temperature catazonal, medium-temperature mesozonal and low-temperature epizonal metamorphism. The samples were subjected to crushing, sorting, grinding and flotation. The best results were obtained for graphite-bearing high-grade metamorphic rocks such as those from Muran and Kokava nad Rimavicou. The graphite contents of flotation concentrates were in the range 67-77% with enrichment factors of 19-24 for the highly crystalline graphite. Poor results were obtained with the epizonal graphite-bearing rocks such as those from the Male Karpaty and Spis-Kermer mountains, with the graphite contents in the concentrates being 20.1-27.9% with enrichment factors of only 4.8-6.5 for the more amorphous graphite. The results confirm that higher metamorphic temperatures increase the crystallinity of the graphite, leading to improved processing characteristics.

Bodies of high-silica and alunimo-metasomatic rock occur in the Vihorlat Mountains in places of crater-feeding systems of the central Morske Oko stratovolcano and in crater zones of parasitic volcanoes. The rocks are fine-grained and composed mainly of quartz to quartz-chalcedony with topaz. Another type of high-silica and alumino-metasomatic rock occurs in bodies located along contacts of diorite to diorite porphyrite intrusives. These rocks are coarse-grained and composed of andalusite, topaz, hydromica, corundum, boehmite, diaspore and quartz. Both stages of epithermal mineralisation are divided by a pronounced tectonic event. Laboratory tests have shown that the material can be used as high-quality refractories or for the extraction of fluorine., Bodies of high-silica and alunimo-metasomatic rock occur in the Vihorlat Mountains in places of crater-feeding systems of the central Morske Oko stratovolcano and in crater zones of parasitic volcanoes. The rocks are fine-grained and composed mainly of quartz to quartz-chalcedony with topaz. Another type of high-silica and alumino-metasomatic rock occurs in bodies located along contacts of diorite to diorite porphyrite intrusives. These rocks are coarse-grained and composed of andalusite, topaz, hydromica, corundum, boehmite, diaspore and quartz. Both stages of epithermal mineralisation are divided by a pronounced tectonic event. Laboratory tests have shown that the material can be used as high-quality refractories or for the extraction of fluorine.

Statistical appraisal of sampling in the deposit disclosed the presence of the following rock varieties: carbonate-steatite-chlorite rock (36.2%), chlorite-steatite slate (29.3%), steatitised carbonate (13.8%), steatite slate (12.1%) and steatite-chlorite slate (3.4%). Three technological types of raw talc are represented. The magnesite-steatite type yielded steatite concentrate of OO/A technological type, with a recovery of 87%, further treatment using electromagnetic methods resulted in EK-II technological type. The steatite-dolomite type yielded steatite concentrate with a recovery of 53.3%, further treatment resulted in EK-I technological type with a recovery of 77.3%. Primary flotation treatment of the steatite-magnesite types yields magnesite of la to lb technological type, with a recovery of 97.8%., Statistical appraisal of sampling in the deposit disclosed the presence of the following rock varieties: carbonate-steatite-chlorite rock (36.2%), chlorite-steatite slate (29.3%), steatitised carbonate (13.8%), steatite slate (12.1%) and steatite-chlorite slate (3.4%). Three technological types of raw talc are represented. The magnesite-steatite type yielded steatite concentrate of OO/A technological type, with a recovery of 87%, further treatment using electromagnetic methods resulted in EK-II technological type. The steatite-dolomite type yielded steatite concentrate with a recovery of 53.3%, further treatment resulted in EK-I technological type with a recovery of 77.3%. Primary flotation treatment of the steatite-magnesite types yields magnesite of la to lb technological type, with a recovery of 97.8%.