Chromic slag wet method detoxifcation and resource comprehensive utilization new technique

Abstract

A new harmless comprehensive utilization technique for wet processing chromic slag comprises steps as follows: ball milling chromic slag to 80-200 meshes, adding water to prepare slurry, immersing the slurry in hydrochloric acid solution, regulating the pH to 5-6, performing solid-liquid separation with filter press, in the immersion liquid after separation, the hexavalent chrome is reduced to trivalent chromium, adding sodium hudroxide aqueous solution, regulating the pH to 4-6, roughly preparing chromic hydroxide, adding sulfuric acid into filtrate, regulating the pH to 5-6, removing the calcium coprecipitated with magnesium in the rest filtrate, preparing the 2-water calcium sulphate whisker, adding alkali to the filtrate after filter-pressing to regulate the pH to 9-12 to synthesize super-fine magnesium hydroxide powder; the solution after filter-pressing is concentrated to prepare sodium chloride. The main contents of extracts within the chromic slag treated by wet processing all can meet primary, secondary or even accredited national or ministerial standard. The technique can thoroughly detoxicate Cr<6+> in chromic slag and can prepare nine products, includiing chromic hydroxide, magnesium hydroxide, ammonium hydroxide, silicon dioxide, magnetic ferrous ferricoxide, 2-water calcium sulphate, corundum intermediate, sodium chloride, and tailings-chromite; and the extracts after processing chromic slag have high quality.

Description

a technical field [0001] The invention relates to a comprehensive resource reuse, in particular to a reuse of industrial waste dregs and chromium slag discharged during the production of products using chromite ore. Two technical background [0002] The chromium salt industry is an indispensable and important industry for the development of the national economy. The industrial waste slag discharged from the chemical industry and metallurgical industry in the process of using chromite ore to produce products - chromium slag is a highly toxic and hazardous solid waste . The harmful components in chromium slag are mainly hexavalent chromium ions such as water-soluble sodium chromate and acid-soluble calcium chromate. Dust, water, and soil containing hexavalent chromium ions will cause serious pollution and harm to the ecological environment. [0003] Dealing with chromium slag has always been the most troublesome problem in the chromium salt industry, and it is also a difficu...

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Problems solved by technology

[0007] The above-mentioned chromium slag treatment technologies all have certain limitations. Some detoxification is not complete and there is secondary pollution; chemicals, the impact on the environment is unknown

In addition to the above disadvantages, there is also the same disadvantage: the resource utilization rate is too low, the economic benefit is too poor, and it is not suitable for large-scale production

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