Dolomite powder prices in Kunming
The use of I2-Nal-H2O system in Beijing light gold recovery of precious metals from waste electronic components in metallurgical plant. Dissolution of gold coating on waste components, recovery of gold by iron replacement or sodium sulfite reduction. Regeneration of iodine by oxidation of potassium chlorate with sulfuric acid. A new process of electrolytic gold removal has been developed at the Institute of materials recycling research. Thiourea and sodium sulfite were used as electrolyte, graphite as cathode plate, and gold plating waste as anode. After electrolysis, the gold on the coating is oxidized to Au+ to form a complex cation Au[cs (NH2)]2+ with thiourea, which is then reduced to gold by sodium sulfite and deposited at the bottom of the tank. The gold precipitate is separated and purified to obtain pure gold powder. The matrix material can be recovered from cobalt and nickel. The recovery rate of the process gold is 97~98%. Product gold purity >99.95%.
From the cultural relics gold copper recovery gold material recycling by oxidizing roasting by research from waste copper recovery of gold gold artifacts. With the waste into a special cultural relic copper roasting furnace, 1000C isothermal oxidation roasting for 30 minutes, take out into the water, with the layer attached to the copper oxide and copper matrix from scales. Then, dilute sulfuric acid is used to dissolve the slag to separate and purify gold. This method features no pollution when roasting. This method is used to treat waste cultural relics with 300 kilograms of copper and 1.5 kilograms of gold. The recovery rate of gold is >98%, the recovery rate of matrix copper is >95%, and by-product copper sulfate can be used as pesticide.
From waste catalyst recovery of gold and palladium with hydrochloric acid and oxidant Kunming Institute of Precious Metals Jin Heba repeatedly leaching into the solution, hydrochloric acid and zinc oxide were dissolved, oxalic acid reduction gold powder; purification of palladium by conventional method liquid reduction. The purity of gold and palladium can reach 99.9%. The recoveries were 97% and 96% respectively.
