The method of melting a rough gold
(57) Abstract:The method of melting a rough gold is designed to clean gold from mercury. How is that for a flux consisting of (in parts by weight) 100 borax, 50 soda and 3 nitrate, add at least 2% by weight of the original flux sulfur and sodium fluoride or potassium. Flux with a rough metal melted at 1100 - 1150°C. the method can reduce the mercury content in the product, as well as in pairs and secretions during melting and casting. 1 C.p. f-crystals, 1 table. The invention relates to pyrometallurgy and can be used in the purification of crude concentrates of precious metals from impurities.There is a method of enrichment of metal concentrates brushless fuse (see , for example, Karpukhin, A. I., V. S., the Use of pyrometallurgical techniques of melting in gold mining, in Proc.: "Precious metals and precious stones: quarrying and extraction of ores, Sands and secondary raw materials", Irkutsk, 1996). The method consists in the fact that the original concentrate gold mixed with a flux consisting of soda, borax, lime and glass, and fused with electrodes made from silicon carbide, immersed in the slag melt. The disadvantage of this method is nevozmozhno is centrata, containing mercury, as well as significant loss of gold due to entrainment of his gas, spray due to local overheating of the electrodes.Closest to the invention is a method of melting a rough gold in the crucible (see Baryshnikov of the Imperial family and other Probootborniki and analysis of noble metals. M, metallurgy, 1968, S. 95-97). How is that rough gold obtained on gold extraction plants, dredges, hydraulic installations and flushing devices using mercury to extract the metal is melted in a graphite crucible. As the fluxes used for soda, borax and nitrate in the following proportions in parts by weight: 100 borax, 50 soda, 3 nitrate. In highly contaminated gold in the mixture add the quartz.The disadvantage of the prototype is incomplete removal of mercury from an alloy with a small duration of melting and the release of harmful fumes when melting and casting metal.The technical result achieved by the invention, is to reduce the mercury content in the product, as well as in a significant decrease in the content of mercury in pairs and secretions during the smelting and casting of metal.This technical result is achieved due to the fact that the way the parts by weight: 100 borax, 50 soda and 3 - nitrate, melting is carried out in a graphite crucible, in this case, according to the invention, the composition of the flux introduce additional components: sulfur and sodium fluoride or potassium in an amount of not less than 2% of the mass of the initial flux of each additional component, the melt temperature support in the range of 1100-1150oC. In case of strong pollution to the mixture add the quartz.Adding to the melt components that react with the components of the melt promotes the redistribution of these components between the phases of the melt. Mercury forms a fairly strong connection with sulfur and fluorine, so the introduction of the flux and sulfur and sodium fluoride promotes rapid removal of mercury from an alloy of noble metals in the slag due to the proximity of the surface tension of melts of salts of mercury (sulfides and fluorides) and the slag melt. This significantly reduces the release of mercury vapor metal, because the distribution of salts of mercury to slag keeps these salts from thermal decomposition temperature melting draft gold is 1100-1150oC. At a lower temperature the mobility of the melt is lower and at higher temperatures there is a danger of intoxication gold.An example of the second amalgam on the mine site mine "Shore" of the Amur region. The data given in the table. 1. The method of melting a rough gold, namely, that before melting in the original product add a flux consisting of a mixture of borax, soda and nitrate in the ratio in parts by weight: 100 borax, 50 soda and 3 nitrate, and melting is carried out in a graphite crucible, characterized in that the composition of the flux introduce additional components, sulfur and sodium fluoride or potassium in an amount of not less than 2% of the mass of the initial flux of each additional component, while the temperature of the melt is maintained within the interval 1100 - 1150oC.2. The method according to p. 1, characterized in that the mixture add the quartz.
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