Mária Kušnierová

The release of sulphidic minerals from aluminosilicates by Bacillus strains

The influence of bacterial strains mixtures of Bacillus species on the structure of mineral samples in the form of polished sections and granulated products subsequently to ore dressing at the Banskfa Hodrusa deposit was investigated. These bacterial strains were isolated from a mining dump near Banska Stiavnica and from a kaolin pit near Horna Prievrana. The ability of our bacteria to destroy some silicates and to produce the release of several metal cations from their structure was confirmed by morphological changes of the mineral surface in comparison with the control samples after 20 days of bioleaching. In the polished sections quartz and silicates were the predominant minerals, whereas sphalerite, galena, rhodonite, pyrite and finely disseminated gold were present in traces. The main metabolites of our bacterial strains detected by the capillary isotachophoresis methodwere acetic acid, butyric acid, pyruvic acid, lactic acid and formic acid. The biodegradation ability of our strains was also confirmed by X- Ray analysis and by the removal of individual metal cations from the samples determined by atomic absorption spectrometry. These methods showed the different activity of these strains on mineral samples. The mixture of Bacillus strains extracted 39% Si, 60% Pb, 43% Zn and 32% Cu from flotation concentrate, 33% Si, 75% Pb, 76% Zn, 76% Cu and 82% Mn from post-flotation waste, 30% Si, 59% Pb, 35% Zn, 56% Cu, 78% Mn, 37% A1 and even 30 % Au from gravitational concentrate.

Effects of biodegradation and mechanical activation on gold recovery by thiourea leaching

The work reported here shows the positive influence of the biodegradation of the crystal lattice of sulfides on the thiourea leaching of gold from an arsenopyrite-pyrite concentrate. Physical processing of the original as well as of the biologically processed concentrate favorably influenced gold recovery. Mechanical activation appears to be unimportant for gold extraction from the investigated concentrate.

Fly ash as the component of composites materials

Abstract The fly ash from powerplant can be compared, due to its genesis, chemical and mineralogical composition with the natural volcanic glasses and minerals generated in the process of devitrification in situ. Its quality is comparable to non-metallic alumosilicate raw materials that are commercially used in building and ceramic industry. Two possibilities of fly ash utilization as the most bulk waste produced by anthropogenic activity were examined. The way of fly ashes utilization in the modeling of mixtures for the high refractory mullite corundum materials synthesis was examined. In this experiment 95.5% conversion of the input components of fly ash and Al additive in the ratio 1:1 on the mullite and corundum was obtained.

Bio-chemical methods in wasteprocessing

Bio-chemical methods in wasteprocessing The mineral biotechnologies, the domain of which is primary raw material processing, are increasingly diversifying into some metallurgical areas. The presented results of the research carried out with metallurgical wastes from aluminium production, lead waste remaking and desulphurization zinc-ferrite-based sorbents regeneration prove the possibility of the use of bio-chemical methods. The results obtained and the proposed technologies applying bio-chemical processes enable a complex processing and use of waste sludge from aluminium production and the use of wastes from matte-based copper production for the production of hematite pigments. The use of microorganisms in the desulphurization sorbent regeneration processes allows to increase sorbents efficiency and its repeated recycling.

Mechano-chemical treatment of tetrahedrite as a new non-polluting method of metals recovery

Laboratory investigations were performed with tetrahedrite concentrate from Maria—RoŽňava mine in Slovakia having the chemical composition of 21% Cu, 11% Sb, 28% S, 1% As, 2% Zn, 0.2% Ag and 1% Hg. X-ray analysis reveal following proportions of dominating phases: 41% Tetrahedrite (Cu4Sb4S13), 12% Chalcopyrite (CuFeS2) and 25% Pyrite (FeS2). Chemical leaching tests with Na2S-solutions indicate that only half of the antimony in the concentrate can be recovered, whereas mechano-chemical leaching in a stirred ball mill under similar leaching conditions a nearly complete and selective antimony extraction is achieved. According to X-ray analysis the increased extraction by mechano-chemical leaching might be related beside the grinding action to the transformation of tetrahedrite into covelite (CuS), Depending on the degree of disorder in tetrahedrite the chemical and bacterial leaching of the solid residues after mechano-chemical treatment with CS(NH2)2/Fe2(so4)3 solution silver recoveries from 50–90% and with Thiobacillus ferrooxidans-medium copper recovery was 74–84%.

Kinetyka flotacji drobnouziarnionego węgla kamiennego z kopalni Staříč za pomocą olejów popirolitycznych

Badania wykonano dzieki finansowemu wsparciu Institute of Clean Technologies for Mining and Utilization of Raw Materials for Energy Use (Ostrawa, Republika Czeska) w ramach projektu nr LO1406 oraz nr 7AMB14SK019.

Kinetics of flotation of fine grained coal from Staříč mine by using pyrolysis oils

Badania wykonano dzieki finansowemu wsparciu Institute of Clean Technologies for Mining and Utilization of Raw Materials for Energy Use (Ostrawa, Republika Czeska) w ramach projektu nr LO1406 oraz nr 7AMB14SK019.

SORPTION OF COPPER AND ZINC CATIONS BY BIO- MODIFIED BROWN COAL

Knowledge on the mechanism of microorganisms participation in the elements cycle and their role in the environmental equilibrium establishment that leads to new generation of environmental biotechnologies evolution is significantly growing. Biotechnological methods have wide application area in the remediation of heavy metals from wastewaters. We studied bio-modification of brown coal sorption materials with the aim to enhance its sorption properties. The micromycetes (Aspergillus niger, Aspergillus clavatus, Penicillium glabrum and Trichoderma viride) have been selected for biological activation of coal samples. The quantitative maceral composition and specific surface of prepared sorbents has been investigated. The sorption of copper(II) and zinc(II) ions from aqueous solutions by this unconventional sorbents was studied. It was found that, for each sorbent the equilibrium establishing time was about 1 h. The Langmuir adsorption model was applied to describe isotherms and isotherm constants. The isotherms studies revealed that prepared sorbents exhibited relatively high capacity for the metals removal.

The application of sulphate-reducing bacteria in hydrometallurgy

The occurrence, characteristics, scientific and practical significance of sulphate-reducing bacteria (SRB) are discussed in this article. On the basis of the natural biological activities of SRB., i.e., their isolation and cultivation, and their chemistry of autotrophic and heterotrophic reduction of sulphates, a process utilizing SRB in Cu-removal from solution is described. Some practical applications in hydrometallurgy are also examined.