Precious metals smelting method for anode sludge or nonferrous smelting slag

Abstract

The invention discloses a noble metal smelting method of anode slime or nonferrous smelting slag, belonging to noble metal smelting technical field, which is used in noble metal recovery, which is characterized in that (1) the crude silver as well as silver-copper-bismuth alloy are generated in the fire method silver separating, entering into smelting slag of partial silver is prevented, the recovery rate of silver is raised, (2) the silver-copper-bismuth alloy is separated by wet separating and melted by nitric acid, the silver is precipitated by chlorination, the bismuth is precipitated by adjusting pH value, the copper is extracted by electrodepositing, the silver entrapped by copper and bismuth is produced in the wet separating, and that copper and bismuth are recovered in the open circuit. The noble metal smelting method of anode slime or nonferrous smelting slag has the advantages of recovery of copper and bismuth, high silver recovery rate, and preparing for fire method recovery of lead and antimony.

Description

technical field [0001] The invention relates to a precious metal smelting technology, more specifically, it relates to a precious metal smelting method of anode slime or non-ferrous smelting slag. Background technique [0002] There are currently three methods of silver smelting: fire method, wet method, and fire-wet method combined process. Pyro-smelting is a relatively traditional method. Generally, crude silver is produced by pyro-smelting, and the oxidized slag is returned to the lead system for recycling. Wet smelting uses acidification to dissolve various metals into the solution, and then separates silver and other metals. There are also two types of fire-wet joint processes. One is that the fire method produces coarse silver, and the oxidation slag also contains a large amount of silver. In order to effectively recover silver and other precious metals, the oxidation slag is treated by wet method to separate silver and other valuable metals. The other is the leachi...

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Problems solved by technology

[0003] The advantage of the single fire method is that the process is mature, the operation is easy to master, and the investment cost is not large; the disadvantage is that the yield is low, generally only about 80%, high energy consumption, and high production costs

The remaining metals are recovered by returning to the furnace, causing a large amount of harmful substances to circulate repeatedly in the system, resulting in a large load on the previous smelting system, which is not conducive to comprehensive recovery, resulting in high pollution

[0004] Single wet method, the yield of precious metals is increased to about 90%, but the yield is low

The metals in the raw materials turn into salts, which is difficult to comprehensively recycle later, and easily produces nitrogen, sulfur, arsenic and chlorine oxides to pollute the environment

At the same time, a large amount of salty wastewater is produced, which is also an important factor of environmental pollution.

[0005] More advanced one-point ignition method----wet method combined process, wet treatment of oxide slag produced by silver separation furnace, leaching copper, bismuth, etc., the yield of silver and other precious metals is significantly improved, and the silver recovery rate can reach 95% % or more, but can not avoid the shortcomings of wet method, comprehensive recovery is difficult, nitrogen, sulfur waste gas and waste water are still the main problems of polluting the environment

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