T. A. Ivanova

New complexing agents to select auriferous pyrite and arsenopyrite

The authors propose the process for selective flotation of auriferous pyrite and arsenopyrite, where the combination of xanthate, 2-hydroxylpropyl ester of diethyldithiocarbamate acid (HPEDEDCA) and oak-bark extract (OBE) is used to produce pyrite concentrate recovered into the froth product. The process provides the selective recovery of valuables into heteronymous concentrates, thus reducing the irrecoverable valuable component loss by 5–7 %. The complexing capacity of HPEDEDCA to gold is experimentally proved and allows using it as a selective collector of auriferous iron sulfides. The use of OBE to depress iron sulfides and arsenic in flotation of multicomponent ores contributes to higher flotation selectivity and grade of heteronymous concentrates.

Composition of multicomponent heracleum extracts and its effect on flotation of gold-bearing sulfides

Using the proprietary method, the authors have obtained flotation agent BO—extract of atomized leaves and stalks of Heracleum sosnowskyi (hogweed), and analyzed its composition. Qualitative tests, thin-layer chromatography (TLC), ultraviolet spectrophotometry and flotation tests show that aqueous and organic extracts contain substances that differ in chemical and process properties. The article gives test results for aqueous, alcoholic and aqueous–alcoholic extracts BO used as modifiers in chalcopyrite and pyrite flotation. Selective properties of aqueous and aqueous–alcoholic extracts BO are characterized. The highest depression ability relative to pyrite is a characteristic of aqueous BO extract obtained at pH = 3, with heating and treatment in ultrasonic bath. Organic extracts contain mostly furocoumarins, aspic oils and resins, and have no material effect on flotation activity of pyrite.

New experimental evaluation techniques for selectivity of collecting agents for gold and platinum flotation from fine-impregnated noble metal ores

It is proposed to apply nanosize Au and Pt particles to ground mineral particles for the analysis of flotation and adsorptive properties of new reagents. The authors have obtained specimens of pyrite, arsenopyrite and quartz artificially enriched by nanosize gold particles. Reductive adsorption from Na2[PtCl6] and Na[AuCl4] produced pyrrhotine uniformly applied with microsize platinum particles. The article discusses the application range of the proposed techniques and methods of examination of specimens and interaction between reagents and micro- and nanosize gold and platinum particles depending on the conditions of sulfide treatment by the noble metals and on properties of a host mineral. Advanced integrated analysis of interaction between the nitrogen-bearing reagent MTKh and gold confirmed chemically induced selectivity of MTKh towards gold

Physicochemical effect of modified diethyldithiocarbamate on the surface of auriferous sulfide minerals in noble metal ore flotation

Complexing processes between modified diethyldithiocarbamate (DDC) and copper, iron and gold ions in solution, as well as adsorption of modified solution on auriferous pyrite and arsenopyrite are analyzed using the ultraviolet spectroscopy, scanning electron and laser microscopy. The research shows that modified DDC forms partial water soluble compounds with gold and is selective towards auriferous pyrite and arsenopyrite as compared to xanthate.

Mechanism of Interaction of Cloud Point Polymers with Platinum and Gold in Flotation of Finely Disseminated Precious Metal Ores

ABSTRACT Prospects of the application of new class of reagents - cloud point polymers with functional groups on the gold and platinum for extraction of micro- and nanoparticles of noble metals from fine grinded ores and by-products were considered. The reaction of synthesis of cloud point copolymer on the basis of N-isopropylacrylamide and N-acryloxysuccinimide, and its subsequent modification by groups of thioamine (TMPA), semicarbazide up (TMPB) and phosphine (TMPPh) were presented. Selective interaction of reagents TMPA, TMPB and TMPPh with noble metals and their prospective use as effective flocculants and reagents-collectors in flotation of refractory gold and platinum ores was revealed.

Methods of Minerals Modification by the Micro- and Nanoparticles of Gold and Platinum for the Evaluation of the Collectors Selectivity at the Flotation Processing of Noble Metals From the Fine Ingrained Ores

The paper explicates methods of the mineral surface coating by noble metals allowing to obtain samples with micro- and nanoparticles of Au and Pt, simulating natural objects. The purpose is to investigate the sorption and flotation properties of collectors. As a result we obtained the samples of pyrite, pyrrhotine, arsenopyrite, and quartz artificially enriched by micro-sized and nano-sized particles of noble metals. The coating of noble metals was carried out using the method of reducing adsorption from H2[PtCl6], H[AuCl4], Na2[PtCl6], and Na[AuCl4] solutions and the method of adsorption of nano-sized particles from Au and Pt sols. Depending on the conditions of the sulfides enrichment by noble metals and sizes of new formations of Au and Pt, we considered possible areas of application, methods of samples’ research, and reagents interaction with microparticles and nanoparticles of gold and platinum. A complex of research methods of reagents’ interaction with metals and flotation investigations of minerals and ores revealed the selective properties of new complexing collectors (perhydro-1,3,5-ditiazin-5-yl-methane (MTKH), sodium di(isobutyl)dithiophosphinate (DIF), 2-(ethylthio)ethylamine (ETEA)) due to their chemical interaction with gold and platinum.

Improved selectivity of sulfide ore flotation

The article analyzes flotation and adsorption capacity of a new complexing reagent AMD (nitrogen and oxygenated organic compound belonging to phenylpyrazole class) toward sphalerite, chalcopyrite and pyrite, combined with complexing modifiers, at varied consumptions of the reagents, in wide range of alkalinity. The basis for improvement of pyrite and sphalerite separation in flotation is provided.

Enhancing multipurpose use of cow-parsnip in processing of gold-bearing sulfides

The authors consider variants of multipurpose use of plant materials—ground green mass of Sosnovsky cow-parsnip. Simultaneous production of aqueous extract possessing depression properties and post-extraction solid residue being a sorbent for ions of gold and finely dispersed gold-bearing particles is one of the ways toward the reduction in cost and environmental impacts of flotation of gold-containing products. The SEM and UV spectrophotometry shows sorption activity of solid residue of cow-parsnip relative to Au3+ ions. It is demonstrated that the studied vegetable sorbent is applicable to additional recovery of finely dispersed gold from flotation pulp. The introduction of cow-parsnip instead of xanthogen in treatment of tailings has enhanced efficiency of fine gold recovery.

Complexing collecting agent for selective flotation of chalcopyrite

Under analysis is interaction between 1-phenyl-2,3-dimethylaminopyrazolone-5 (AMD) and copper in solution and on the surface of chalcopyrite. It is found that AMD experiences chemical adsorption on the surface of chalcopyrite as a compound with copper. Effect exerted on adsorption of AMD agent on copper sulfide by ammonium rhodanate (NH4CNS), introduced as an additional ligand, or its mixture with acetic acid is defined. Based on the analytical research and the analytical chemistry data, the type of adsorption on the surface of chalcopyrite is determined. The flotation tests on monomineral fraction of chalcopyrite and pyrite, and copper sulfide ore prove selectivity of AMD in separation of chalcopyrite and pyrite.

Gold mineral flotation versus preparation conditions in a complexing agent belonging to dithiazinanes

To gain the efficient and optimized application of agents MTH and ETH belonging to dithiazinanes to float gold from complex ores the investigation was undertaken on complexing conditions in water environment and at pyrite surface with manually attached gold (FeS2Au) prior to flotation tests. The microscopic and spectral analysis of (FeS2Au) surface after contact with MTH and ETH show the presence of organic S- and N-containing compounds. It is found that selective gold recovery from a gold-bearing material in flotation with MTH and ETH is conditioned by a number of factors that accelerate formation of poorly soluble compounds at the surface of gold particles. The analysis includes the contact time, optimal medium alkalinity, formation of an oxidized film at Au0 particle surface, introduction of modifying agents as additional ligands as well as mechano-chemical acceleration of the complexing. Mechano-chemical treatment with feeding a low soluble agent into a mill before flotation of copper-sulfide gold-bearing ore enabled to higher gold recovery into rough and intermediate flotation concentrates by 15.9 and 4% respectively. In this case Au content in tailings was lowered by 0.15 g/t as compared to flotation experiments with butyl xanthate and its combinations with ETH.