Overview of gold recovery from nickel anode slime

The raw materials for the production of nickel are mainly nickel sulphide (or copper sulphide) and nickel oxide minerals. In addition, the use of blast furnace production of calcium plus magnesium serpentine phosphate fertilizer plant, brought by the serpentine nickel is enriched in the blast furnace slag, blast furnace slag by blowing this (Ni-P alloy iron) from which Recover nickel. The smelting of nickel concentrate and the crude nickel produced by the blowing of nickel-phosphorus iron enrich almost all precious metals. The electrolysis of the crude nickel further enriches the precious metal in the nickel anode slime. The composition of the nickel anode mud varies greatly depending on the raw materials for the production of nickel. Typically, the nickel anode sludge containing mainly nickel, copper, iron, sulfur, and SiO _2, etc., typically contain noble metals platinum-based, gold, silver content less. The yellow type components of some nickel anode muds are shown in Table 1.

Table 1 Composition of nickel anode mud in some plants at home and abroad (%)

   Note: The anode mud produced by NiPFe raw materials in Plants 2 and 3

In the early days, pyrometallurgy was used to smelt nickel anode mud, and then the precious metal was separated and recovered from the enrichment. In recent years, due to the development of hydrometallurgical technology, some factories have adopted the liquid chlorination process to treat the nickel anode mud process. Since the precious metal content in the nickel anode slime is generally not much, the secondary electrolytic enrichment process for recovering precious metals has been paid attention to.

The method of enriching precious metals from nickel anode mud is similar to the treatment of copper and lead anode mud.