Arsenic fixing method for preparing scorodite through stabilization treatment of arsenic-alkali residue

A technology for stabilization treatment and arsenic-alkali slag, applied in chemical instruments and methods, inorganic chemistry, iron compounds, etc., can solve the problems of secondary pollution costs, etc., and achieve the effect of simple and energy-saving equipment, simple reaction operation, and high uniformity
CN109809494AActive Publication Date: 2019-05-28CENT SOUTH UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
CENT SOUTH UNIV
Publication Date
2019-05-28

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Abstract

The invention discloses an arsenic fixing method for preparing scorodite through stabilization treatment of arsenic-alkali residue. The arsenic fixing method comprises the following steps: (1) the arsenic-alkali residue is subjected to oxidation leaching, filtering is conducted to obtain leachate containing sodium carbonate and sodium arsenate, and sodium antimonite precipitation, after the leachate is concentrated, CO2 is introduced for dealkalization, and filtering is conducted to obtain dealkalized leachate and sodium bicarbonate crystals; (2) acid is added into the dealkalized leachate obtained in the step (1) to control the pH of the dealkalized leachate to be 1.0-2.5, and an arsenic-rich solution is obtained; and (3) a mixed solution of ferrous salt and H2O2 is added into the arsenic-rich solution obtained in the step (2) according to the iron-arsenic molar ratio of 1.0-3.0, the pH of the mixture is controlled to be 1.2-2.0, the mixture reacts at 75-95 DEG C, and scorodite crystals are obtained. The arsenic-alkali residue is treated to obtain the scorodite crystals with the double-cone octahedron shape and uniform particles, the arsenic leaching concentration is lower than the concentration stipulated by the GB5085.3-2007 'hazardous waste identification standard-leaching toxicity identification', and the scorodite crystals can be safely stored for a long term.
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Description

technical field

[0001] The invention belongs to the technical field of hazardous solid waste treatment, and in particular relates to an arsenic fixation method for preparing scorodite by stabilizing arsenic-alkali slag. Background technique

[0002] In antimony smelting, the crude antimony is usually refined by the alkaline refining method, that is, the method of adding alkali and blasting, to obtain refined antimony and a by-product of alkaline slag with a high arsenic content, namely, arsenic-alkali slag. At present, the total stockpile of domestic arsenic-alkali slag has reached 200,000 tons, and it is still increasing at a rate of 5,000 to 10,000 tons per year. Arsenic-alkali slag contains sodium arsenate, a soluble and highly toxic arsenic-containing compound. Once leaked, it will easily cause water pollution, soil pollution and farmland pollution. If it is not disposed of properly, arsenic in the environment may enter the human body through the enrichment of the food c...

Claims

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