Stable curing method of strongly acidic arsenic sulfide waste residues

Abstract

The invention discloses a stable curing method of strongly acidic arsenic sulfide waste residues. The stable curing method comprises the following steps: (1) adding heavy-metal sludge to to-be-treated strongly acidic arsenic sulfide residues, and stirring, so as to obtain muddy materials; (2) adding calcium hydroxide powder to the muddy materials obtained in the step (1) in the state of stirring, and continuing to stir until all yellow substances in the muddy materials disappear; (3) adding yellow sand and cement to the materials obtained after stirring in the step (2); (4) cooling the stirred materials obtained in the step (3) to room temperature, transferring to a forming die, taking out from the die after forming, and curing at room temperature, so as to obtain solidified bodies which conforms to the landfill standard. According to the stable curing method, the heavy-metal sludge is used as an arsenic stabilizer, so as to control waste by waste; sources of the materials such as the heavy-metal sludge, the lime, the cement and the yellow sand required for treating the strongly acidic arsenic sulfide waste residues are wide, and additionally, other drugs do not need to be added; compared with other methods, the stable curing method has the advantage of low treatment cost.

Description

technical field [0001] The invention relates to a harmless treatment process for solid hazardous waste, in particular to a stable solidification method for strongly acidic arsenic sulfide waste residue. Background technique [0002] In the sulfuric acid and phosphoric acid industries, sulfide (hydrogen sulfide or phosphorus sulfide) is added under strong acidic conditions for deep arsenic removal. The resulting arsenic sulfide slag is orange and has strong acidity, containing 10% to 20% of arsenic. The pH value of the leaching solution of arsenic slag is 0.5-2.0, and the content of arsenic in the leaching solution measured by leaching toxicity test is 1560 mg / L-1780 mg / L. According to the survey, a sulfuric acid or phosphoric acid production enterprise with an annual output of 10 tons produces more than 300 tons of arsenic sulfide yellow residue every year. If not handled properly, these strongly acidic arsenic sulfide residues will pose a serious threat to the environment....

AI Technical Summary

Problems solved by technology

The second is the wet method, which uses acid leaching, alkali leaching or salt leaching to separate the arsenic from the waste residue, and then further recover arsenic products or perform harmless treatment; the wet method has the advantages of low energy consumption, less pollution, and high efficiency. High advantages, but the process is complicated and the processing cost is high

However, the maintenance time of this process needs 28 days, and the maintenance time is too long, which is not conducive to the improvement of efficiency in the actual production process

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