Thoughts on this - silver loss ????
Method for extracting metallic silver from silver chloride sediment
Abstract
The invention discloses a method for extracting metallic silver from silver chloride sediment. The method is characterized in that: silver chloride slag is subjected to dechlorination conversion by using sodium carbonate, and the dechlorinated silver slag is smelted. The method comprises the following steps of:(1) mixing the silver chloride sediment and anhydrous sodium carbonate ingredient in an amount which is 40 to 50 percent of the mass of the silver chloride sediment uniformly, roasting, crushing the reaction materials after roasting, stirring and leaching by using hot water, performing liquid-solid separation, and obtaining metallic silver slag and a sodium chloride solution;
and (2) drying the metallic silver slag, adding sodium nitrate and sodium carbonate, fully mixing uniformly, transferring the materials to a graphite crucible, smelting, taking out the totally smelted materials out of the crucible, stirring the melt by using an iron rod so that the melt is fully reacted and demixed, smelting continuously, taking out the melt out of the crucible after smelting, pouring the melt into a pig mold, cooling, knocking off the dross, and obtaining metallic silver ingots.
By the method, the problems of long process flow, low straight yield of silver and the like in a wet method are avoided, and the influence caused by volatilization of chlorides during high-temperature smelting is solved; and the cost in the method is much lower than that in a method using sodium hydroxide.
