Method for industrially eliminating toxic ingredients in chromium slag

Abstract

The invention relates to a method for industrially eliminating toxic ingredients in chromium slag. The method sequentially comprises the following steps: (1) carrying out refluxing for the chromium slag through 1-5% of a KMnO4 solution or a NaClO2 solution, wherein the volume of the KMnO4 solution or the NaClO2 solution is 1-2 times the volume of the chromium slag, then carrying out grinding until the chromium slag has a particle size less than 1 mm; (2) carrying out refluxing and washing for the grinded chromium slag through industrial water in a screw ore washer, wherein the volume of the industrial water is 2-5 times the volume of the chromium slag; (3) collecting the chromium slag, and separating the solid from the washing solution through a cone hydraulic classifier and a hydroclone;(4) collecting the washing solution, and adjusting a pH value of the washing solution to 6-8, followed by adding a saturated CaCl2 solution or a saturated BaCl2 solution until precipitation is not generated; (5) collecting the precipitation, wherein the precipitation is calcium chromate or barium chromate, and carrying out cycling utilization of the supernatant. With the chromium slag detoxication process provided by the present invention, the chromium (Cr) (VI) is eliminated, the total Cr is thoroughly reduced so as to completely meet environmental protection requirements.

Description

Technical field [0001] The present invention involves a method of industrialization to eliminate poisonous components of chromium residue, especially involving a chromium or chromate pyrine prepared from chromium residue to reduce the total chromium content in chromium residue and eliminate the toxic hexavalent chromium in chromium residue.Methods. Background technique [0002] Chromium residue refers to the mixing of chromium iron ore, pure alkali and calcium fillers during the production process of chromium salt, and the gray residue left after being burned and soaked with sodium chromate with high temperature.Chromus dregs contain na 2 CRO 4 , CACRO 4 Waiting for CR (ⅵ) compounds, in addition to its strong oxidation, its toxicity also enters the human body and animals through the skin, digestive tract and respiratory tract, which can induce a series of cancer.Each year, the amount of chromium residue emitted in my country is about 400,000 tons, and the amount of chromium resid...

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Problems solved by technology

[0005] method principle application practice features dry method Mix chromium slag with a particle size of less than 4mm and coal particles at a ratio of 100:15, and perform reduction roasting at high temperature to reduce Cr(Ⅵ) to Cr(Ⅲ) Refining glass colorant, calcium magnesium phosphate fertilizer flux, ironmaking auxiliary agent, cast stone and cement, etc. Valuable products can be obtained, but the processing cost is high, the amount of slag eaten is small, and the detoxification of chromium slag is not complete wet method Add Na 2 S, FeSO 4 and other reducing agents to reduce Cr(Ⅵ) to Cr(Ⅲ) Combined application with reducing papermaking waste liquid and monosodium glutamate waste liquid can achieve the purpose of treating waste with waste Cr(Ⅵ) after treatment≤2×10 -6 , but the treatment cost is high, so it is not suitable to deal with bulk chromium slag curing method Add a certain amount of FeSO after pulverizing the chromium slag 4 , inorganic acid and cement, add water and stir, so that the chromium slag is sealed in the cement and cannot be dissolved

Mainly cement curing, there is also a small amount of asphalt, lime, fly ash, and chemical reagents for curing applications where a large amount of curing agent is added, and the cost is extremely high

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