Method for processing concentrates containing precious metals
The invention relates to the metallurgy of noble metals, in particular to the pyrometallurgical processing of concentrates containing gold and silver. Method for processing concentrates containing precious metals, is that the original concentrate mixed with brown, calcium oxide and silica flux, the mixture is melted and derived products - slag and gold-silver alloy is cooled and separated. What's new is that the composition of the mixture to be melted add the sodium sulfate, carbonaceous reducing agent, as silica flux use silica sand or silica glass in the melting process receive additional sulfide product - Stein. The method allows to increase the efficiency by increasing the content of gold and silver in the target grades. 3 table. The invention relates to the field of metallurgy of noble metals (BM), in particular to the pyrometallurgical processing of concentrates containing gold and silver.Target products gravity beneficiation process gold-bearing Sands and ores are placer gold and gold head. The composition of the obtained concentrates on a group of impurity comodi gold sand, containing pyrite (FeS2), arsenopyrite (FeAsS), chalcopyrite (CuFeS2), Galena (PbS), etc., sulfide components are primarily concentrated in the so-called industrial refining of concentrates, and placer gold. In the industrial refining of concentrates contain up to 8-10% of gold and silver, 5-15% sulphides, the rest of oxide minerals magnetite (Fe3About4), ilmenite (FiO3), quartz (SiO2), etc. In placer gold contains up to 1-4% sulphides, 3-8% oxide minerals, the rest of the gold and the silver.When gravity processing of oxidized gold-bearing ores in the "Golden head" in the middle contains 10-25% of gold and silver, 50-60% of oxide minerals magnetite, limonite (Fe2About3H2O), quartz, and others, and up to 10-20% of metallic iron (scrap), native copper, oxide compounds of non-ferrous metals.There is a method of processing of gold concentrates, including oxidative calcination of the material at 500-700oWith and subsequent melting of candle mixed with ash, silica sand and carbonaceous reducing agent with obtaining gold-silver alloy and slag . The disadvantages of the method are significant losses of noble metals with pylegathon the manual processing of concentrates, containing precious metals, which is taken as a prototype, as the closest to the claimed technical solution .According to the method of the initial concentrate is mixed with brown, calcium oxide and silica flux containing quartz sand, the mixture is melted at a temperature of 1200-1300oWith and obtained the condensed products - slag and metallic gold-silver alloy after deposition divided by the boundary.The disadvantage of this method is the low degree of selection of precious metals from iron and non-ferrous metals, resulting in a higher content of non-ferrous metals and iron in the target gold-silver alloy.The task, which is aimed by the invention, is to increase the efficiency of processing of concentrates containing precious metals, due to the increase in the content of gold and silver in the target alloys obtained in the process of melting of the source concentrates.The problem is solved at the expense of achieving a technical result, which is to improve the selectivity of gold and silver from base metals and iron by concentrating the latest in the sulfide phase and the effective separation of Oh is carried out so that in a known method of processing concentrates containing precious metals, including original mix concentrate with brown, calcium oxide and silica flux, melting the mixture with obtaining gold-silver alloy and slag, and separating the condensed products of fusion, according to the invention, the mixture further comprises sodium sulphate and carbonaceous reducing agent, and as silica flux use silica sand or silica glass in the following ratio, wt.%: Borax - 15-30 calcium Oxide - 1,8-3,0 Silica flux - 3,2-33,2 Sulfate sodium - 2-10 Carbon reducing agent is 0.3 to 1.5 Concentrate containing precious metals - the Rest is in the process of melting receive additional condensed product is matte, which after cooling is easily separated from the slag and gold-silver alloy.The difference of the proposed technical solutions from the prototype is the composition of the mixture to the melting of the original concentrate and getting a new condensed product melting - matte.The purpose of the components of the mixture to the melting of the original concentrate the following. Borax (Na2B4O710H2O) is used as the Le is e on the boundary of the slag - Stein - metal, contributing to the coalescence of drops of gold-silver alloy and matte and release them from the slag phase. Quartz sand or silica glass is introduced to bind in a stable silicate complexes of the slag-forming components of the source and concentrates as a source of silica to the flow of the reaction sulfatirovnie. The sodium sulfate is used for the formation of sodium sulfide and sulfatirovnie non-ferrous metals and iron. Carbon is the reducing agent in the reaction sulfatirovnie.The physico-chemical nature of the separation process of melting in the claimed method is based on the limited mutual solubility in the liquid and solid state of the metal gold and silver and polysulfide type Na2S-MenSmwhere Me is iron, copper, lead, zinc, and others.The composition and formation of the matte phase at melting is the process adjustable and is determined by the composition of the original concentrate BM, the number of fluxes and additives in the charge. When heating and melting of the charge reactions proceed with selection as intermediate products of sodium sulfide and elemental sulfur by reactions 1-3:
When melted at a temperature of 1100-1200oWith primary sulfides contained in the original concentrates BM, and secondary sulfides, formed by reactions 1, 4, 5, form the matte phase melt. Slag-forming oxides are dissolved in an easily fusible slag on the basis of B2O3-Na2O-SiO2-CaO-CaF2-FenOm. Gold and silver form a metal gold-silver alloy, which stands out as the most difficult phase of the melt. After melting and cooling of the melt condensed products are easily separated by the boundary liquation phase separation. Gold-silver alloy is the target product, slag - conditionally otvajnym. Stein contains an average of about 1.0 to 1.5% of gold and up to 5-6% silver, is an intermediate product and is processed in known ways in order to extract BM.The upper and lower limits of the content in a mixture of borax, calcium oxide and silica provide a flux in the smelting of concentrates, BM, respectively with high and low content of slag-forming componentone borax, of calcium oxide and silica flux in the mixture leads to an increase in residual BM in the slag at a flow rate below the proposed limit due to its refractoriness. The increase in the content of borax in a mixture of more than 30%, calcium oxide than 3% and silica flux above 33,2% impractical because not improve the performance of the heat.The upper and lower limit of the content of sodium sulfate in the mixture provide smelting education necessary and sufficient sodium sulfide to its content in the matte at the level of 5-10% and a completeness of sulfatirovnie metallic iron and non-ferrous metals processing concentrates respectively with high and low contents of these components. When the content of sodium sulfate below 2% increases the content of impurities in the gold-silver alloy due to the incompleteness of their sulfatirovnie. The excess content of sodium sulfate for 10% leads to increased solifidian silver and increase its residual content in the matte.The number added to the charge of carbonaceous reductant 0.3 to 1.5% by experimental data provides completeness for the processes of sulfatirovnie impurities and education necessary and sufficient Avraamova method with the prototype shows that the claimed method differs from the known to the introduction of new components in the mixture to the melting of sodium sulfate, carbonaceous reducing agent and of silicate glass and getting a new condensed product of a Stein.To prove compliance of the claimed invention, the criterion of "inventive step" was compared with other technical solutions known from the sources included in the prior art. Using a carbon reductant in the mixture to be melted concentrate BM you know similar to , where the carbon is used to restore the Fe2About3FeO, which reduces the melting point of the slag and residual content of BM. In the inventive method, the carbonaceous reductant is spent on education matte, which gives way to new properties and new effects, such as enhancement of the selection of gold and silver from base metals and iron.The inventive method of processing concentrates containing precious metals, meets the requirement of "inventive step", as it provides a high degree of selection of gold and silver from base metals and iron smelting concentrates BM. The result is higher efficiency equipment.Examples of using the proposed method
For experimental verification of the proposed method used the fluxes and additives, crushed to a particle size less than 0.3 mm, and gold concentrates. Concentrate "And" middlings refining of concentrates obtained during the final cleaning of placer gold. Concentrate "B" placer gold obtained when the gravitational processing of gold-bearing Sands. Concentrate "In" - "the Golden head", obtained by gravitational enrichment of oxidized gold ore. The compositions of the concentrates are shown in table 1.Prepared six charges, each a mass of 100.0 g, three of which corresponded to declare, and three incredible compositions. Each mixture was loaded into Szamotuly the crucible, melted and kept at a temperature of 1250oC for 60 min in furnaces with carbide heaters. After melting crucibles were removed from the furnace and cooled. Products smelting - slag, matte and gold-silver alloy was knocked out of the crucible. shared boundary liquation phases, weighed and analyzed for the constituents of the assay and chemical analysis methods.Data on the composition of the charge, the outputs of smelting products, the content of gold is whether calcium fluoride (CaF2), the connection is similar to that of Cao properties, but allow a more fluid slag.The obtained data show that the inventive method allows for the smelting of concentrates BM get targeted alloys with a high content of gold and silver due to the effective allocation of iron and non-ferrous metals in coexisting sulfide phase - Stein and the subsequent separation of these products. As follows from the obtained results, the inventive method provides for obtaining the target alloys with total content of gold and silver 92,94-99,42%. The transition from the claimed (op.1-3) to incredible mixes for smelting concentrates BM leads to the deterioration process or as a result of reducing the degree of selection of gold and silver from base elements, or because of irrational excess reagents.An example of using the prototype method
To compare the performance of the proposed method and the method of the prototype spent experience processing concentrate "In" technology of the prototype method. The mixture to be melted contained (wt.%, grams): 36.0 concentrate "In"; 37,0 borax; 22,0 quartz sand; 5.0 calcium oxide. Smelting, separation and analysis of products was carried out by the above methods is 5 silver; 17,86 copper; 0.77 lead; to 9.57 iron. In the slag respectively contained, wt.%: 0,143 gold; 0,119 silver; 1,88 copper; 0.03 lead.Comparison of indices from the use of declared and known methods are presented in table 3.The data of table 3 show that using the proposed method allows to obtain the target alloys BM with higher content of gold and silver, which significantly reduced the costs of the subsequent processing of alloys otation.For the proof of the criterion of "industrial application" should indicate that the proposed method is tested on a number of gold mining companies in Russia.Sources of information
1. Patent USSR 1649815, CL 22 In 11/02, 1989.2. RF patent 2086684, CL 22 In 11/02, 1997.
Method for processing concentrates containing precious metals, including original mix concentrate with brown, calcium oxide and silica flux, melting the mixture with obtaining gold-silver alloy and slag and separation of the products of melt, characterized in that the mixture further added sodium sulfate and carbonaceous reducing agent, and as kremnezemami the>Calcium oxide - 1,8-3,0
Silica flux - 3,2-33,2
The sodium sulfate - 2-10
The carbonaceous reducing agent is 0.3 to 1.5
The concentrate containing precious metals - Rest
the smelting of lead from obtaining as an additional product - matte.
FIELD: noble metal metallurgy, in particular method for gold content determination in natural solid organic materials such as divot, state coal, brown coal, and black coal.
SUBSTANCE: claimed method includes sampling the probe of starting material, grinding, mixing with massicot, smelting to form bullion, parting of gold-silver globule, weighting of gold sinterskin. Probe is sampled from starting natural solid organic material. Before smelting mixture is packaged in lead foil, established in full-hot scorifying dish, and padded with borax and table salt.
EFFECT: precise method for gold content determination in natural solid organic materials.
1 tbl, 1 ex
FIELD: waste treatment.
SUBSTANCE: multicomponent waste material is preliminarily impregnated with solution of salt of metal-collector in amount ensuring weight content of metal-collector in melt exceeding content of metallic components therein. Material is then calcined and melted in reductive atmosphere after addition of slag-forming flux based on metal fluorides. Melt is stirred and kept in liquid state over a period of time long enough to allow separation of slag and metallic phases. Resulting slag and metal are tapped and mechanically separated when solidified.
EFFECT: achieved high degree of recovering metals in collecting alloy at minimum expenses.
FIELD: secondary precious metal recovery.
SUBSTANCE: recovery of silver from waste, such as spent catalysts and ashes, us accomplished by charging waste into soda-borax melt taken in such proportions that weight of soda is by 2.0-3.5 times superior to that of oxide constituent of starting material and weight of borax constitutes 8-20% that of soda. Melting is effected at 1120-1350°C and melt is aged then for at least 15-20 min, after which products are separated and silver is recovered. Weight of charged waste (Pw) is found in dependence of content oxide constituent therein using formula (wt %): Pw = (11.5-16.7)MeO+(0.5-1.0)Na2B2O7+9SiO2 ( Me is Ca, Al, or 2Na).
EFFECT: achieved essentially complete recovery of silver.
1 tbl, 5 ex
FIELD: gold mining.
SUBSTANCE: invention relates to selective recovery of gold from gravitation and flotation concentrates of gold-recovery fabrics in the stage of adjusting gold-containing products to condition meeting affinity requirements. Method of recovering gold from gold ore concentrates into lead melt comprises dispersing molten lead at vigorous blade agitator-mediated mechanic stirring in common with gold-containing concentrate in presence of molten alkali (NaOH) at concentrate-to-alkali weight ratio 1:(1-3) and temperature 400-550°C depending on mineralogical composition of concentrate.
EFFECT: accelerated recovery process and increased fullness of recovery.
2 cl, 4 ex
FIELD: noble metal metallurgy, namely separation of platinum group metals and gold from materials on base of non-noble metal chalcogenides.
SUBSTANCE: method comprises steps of treating material with nitric acid solution till oxidation-reduction potential 500-700 mV; extracting non-soluble residue; melting it at adding sodium-containing fluxes, carbon -containing reducing agent and copper- and(or) iron-containing industrial process product obtained at hydrolysis or cementation treatment of solutions of refining production; settling and cooling melt till its solidification. Solidified product is separated according to interface boundaries. Then separated bottom phase of heavy alloy is disintegrated to powder. Method allows to extract to target alloy up to 94% of platinum and palladium, more than 97% of rhodium, iridium and ruthenium. Disintegrated alloy may be processed as concentrate of refining production.
EFFECT: increased content of noble metal in bottom phase, lowered cost of next refining process.
2 cl, 1 ex
SUBSTANCE: proposed method includes reduction of silver chloride at heating and holding at heat in flow of gaseous hydrogen, bubbling of gas escaping from reaction chamber through water and obtaining aqueous solution HCl. Reduction is performed from silver chloride formed at refining of noble metals and ground to size of ≤100 mcm and located in reaction chamber at thickness of layer of ≤20 mm at temperature of 450°C±5°C by gaseous hydrogen heated to holding temperature.
EFFECT: increased degree of extraction of silver from silver chlorides.
1 tbl, 1 ex
FIELD: extraction of noble metals from materials containing such metals, for example sludge, used catalysts, ores.
SUBSTANCE: proposed method increases degree of extraction of noble metals into alloy at eutectic melting due to increased degree of extraction of micro-dispersed phases (nano-particles) and atoms of noble metals found in dislocations (linear defects) and micro-cracks of crystal lattices of initial materials. To this end, material from which noble metals are to be extracted is mixed with charge of alkaline composition and mixture is subjected to eutectic melting, thus obtaining alloy of these metals. Immediately before melting, mixture is subjected to mechanical activation continued for 0.0833-2 h at maintenance of ratio of delivered mechanical energy power to relative surface of mixture within 0.0133-25 W x kg x m-2. Eutectic melting of mixture is performed at temperature above 500°C. Ratio of mass of charge to mass of material is selected within 0.75-2; used as charge is mixture of sodium tetraborate with sodium carbonate, sodium tetraborate with sodium bicarbonate, sodium tetraborate and sodium carbonate and lead mono-oxide, sodium tetraborate with sodium bicarbonate and lead mono-oxide.
EFFECT: increased degree of extraction of noble metals.
4 cl, 12 ex
FIELD: nonferrous metallurgy; methods of detection of the noble metals in the mineral raw materials.
SUBSTANCE: the invention is pertaining to nonferrous metallurgy, in particular, to the methods of detection of the noble metals in the mineral raw materials. The technical result of the invention is an increased trustworthiness to the results of the testing crucible melt analysis. The method is conducted in the following way. From the material of the laboratory test sample take out the analytical part of the filler, mix it with the calculated amount of the charge and the mixture is smelt according to the standard method. During the smelt visually control the height of the boiling layer of the melt slag and lead. On completion of the smelt measure the mass of the slag and lead and calculate an admissible height of the boiling layer of the melt according to the following formula:0,9·Hm≥Hc≥[1,9/tg2α/2·(Mш/ρш+Mc/ρc)]1/3, whereHcr - depth of the crucible in meters(m);Hsl - the height of the boiling gas-slag layer, m; α - an angle at the apex of the cone of the inner surface of the crucible, in degrees;Msl, Mla - masses of the slag and mass of the lead alloy accordingly, kg;ρsl, ρla - density of the slag and density of the lead accordingly, kg/m3. If the visual estimation of the height of the boiling layer of the melt exceeds the limits of admissible values, them one may draw a conclusion about the low quality of the testing smelt, make corrections in the composition of the charge and repeat the test analysis.
EFFECT: the invention ensures an increased trustworthiness to the results of the testing crucible melt analysis.
FIELD: noble metal metallurgy, in particular recovery of non-ferrous, noble metal and alloys thereof from debris of electronic devices and components.
SUBSTANCE: claimed method includes disintegration of radio-electronic debris, vibrating treatment with separation of heavy fraction containing noble metals, metal separation and recovery, wherein radio-electronic debris is sorted, and metal components are separated, remaining debris part is treated with separation of heavy fraction. Said fraction after separation is mixed with preliminary separated metal components and mixture is subjected to oxidative melting with feeding of air blowing in amount of 1.15-0.25 nm3 per 1 kg of mixture. Further obtained alloy is electrolitically refined in copper sulfate solution and noble metals are recovered from formed slurry. Method of present invention makes it possible to isolate 98.2 % of gold, 96.9 % of silver and 98.2 % of platinum.
EFFECT: method of increased noble metal yield.
2 dwg, 6 ex
FIELD: metallurgy of noble metals.
SUBSTANCE: proposed method includes selection of analytical weighted portions from ordinary samples of ore, analysis of weighted portions, forming and analysis of group sample before estimation of mass of weighted portion, estimation of mass of weighted portion, selection of weighted portion from sample at size of grain of 1-0.04 mm and final grinding of weighted portion to 0.2-0.04 mm. During analysis of weighted portions, approximate magnitude of content of gold Co.s. in ordinary samples is determined, group sample is formed from ordinary samples at minimum content of gold, analytical weighted portions are taken from group sample and content of gold Ci is determined, average content of gold in group sample Cg.s. is calculated, minimum mass of analytical weighted portion for group sample Mg.s.(g) is set at ratio Пi=2(Ci-Cg.s.)/(Ci+Cg.s.)≤Дg.s., where Пi is relative discrepancy between content of gold in i-analytical weighted portion and average content of gold in group sample; Дg.s. is permissible relative discrepancy between results of determination of content of gold in group sample during laboratory monitoring; then estimation of mass is performed for ordinary samples Mo.s. by the following formula: Mo.s.= (Mg.s..Дg.s./(Co.s..Дo.s.), where Дo.s. is permissible discrepancy between results of determination of content of gold in ordinary sample during laboratory monitoring.
EFFECT: enhanced rapidness and reliability; low cost of assay.
1 dwg, 2 tbl, 1 ex