Processing method for recovering nickel, chromium and iron from stainless steel factory waste residue

Abstract

The invention discloses a processing method for recovering nickel, chromium and iron from stainless steel factory waste residue. The method is as below: adding mixed acid into the stainless steel factory waste residue, leaching out nickel, chromium and iron in the waste residue, and filtering to separate a pickle liquor and leaching residue; adding sodium sulfide to the pickle liquor under normal temperature, and after reaction conducting solid-liquid separation to obtain nickel sulfide and a filtrate; heating the filtrate, and adding a sodium hydroxide solution and a hydrogen peroxide solution; converting trivalent chromium into hexavalent chromium to stay in the supernatant by an alkali leaching oxidation method, and converting trivalent iron into a ferric hydroxide precipitate, conducting solid-liquid separation to obtain a sodium chromate solution; and recovering the chromium, smelting down the ferric hydroxide precipitate for smelting utilization, and subjecting the acid leaching residue to natural air drying for agricultural landfill. The whole process of the invention does not produce contaminants, and realizes complete recovery and utilization of resources; and the process is simple, easy to operate and low in cost, can effectively solve the problem of waste residue pollution in the production of stainless steel, and has high economic benefit and environmental benefit.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and relates to waste slag recycling technology, in particular to a treatment method for recovering nickel, chromium and iron from waste slag in stainless steel factories. Background technique [0002] In recent years, with the continuous development of my country's economy and the continuous expansion of demand, the production of industrial stainless steel has continued to increase, and the industrial pollution caused by stainless steel production has become increasingly serious. After treatment, the heavy metal-containing waste slag produced will cause serious secondary pollution. The heavy metals have complex forms and are potentially harmful to human health. If this waste residue is not effectively treated, it will cause serious pollution to the environment. [0003] Stainless steel plant waste slag generally contains 8-15% chromium, 20%-30% iron and more than 10% nickel. Many...

AI Technical Summary

Problems solved by technology

[0003] Stainless steel plant waste slag generally contains 8-15% chromium, 20%-30% iron and more than 10% nickel. Many kinds of valuable metals exist at the same time, and ordinary physical and chemical methods cannot efficiently separate them.

If you invest in deep smelting, the cost is too high and the economic benefits are not good

Therefore, many small and medium-sized factories simply do not develop or reuse these waste residues, consume a lot of transportation vehicles, accumulate more and more, occupy a large amount of farmland, and pollute the environment; million

[0004] In recent years, many scholars have studied the recycling of heavy metal-containing waste slag produced after stainless steel waste liquid is treated with ordinary water, such as making such waste slag into building materials or building material additives, but this is only a temporary treatment of waste slag. The disposal of nickel, chromium, iron and other metal ions is still a big hidden danger

There are also researches to use the extractant to recover metals after acid leaching this kind of waste residue, but the separation effect of nickel, chromium and iron in the extraction process is not ideal, and the organic solution cannot be reused, and the investment is very high

Images