1. Separation and recovery of arsenic and alkali products during the treatment of antimony smelting residues.
- Author
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Long, Hua, Zheng, Ya-jie, Peng, Ying-lin, Jin, Gui-zhong, Deng, Wei-hua, Zhang, Shou-chun, and He, Han-bing
- Subjects
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ANTIMONY , *ALKALIES , *ARSENIC trioxide , *ARSENIC , *ARSENIC removal (Water purification) , *SULFURIC acid , *SODIUM sulfate , *RAW materials - Abstract
• Efficient separation and recovery of arsenic and alkali were achieved. • Low consumption of sulfuric acid in the process of deep alkali removal. • The products recovered from arsenic-alkali solution were Na 2 CO 3 and As 2 O 3. • No arsenic-alkali mixed salts were produced in the separation process of arsenic and alkali. For the comprehensive utilization of antimony smelting arsenic-alkali residue, there are some problems such as the incomplete separation and low recoveries of arsenic and alkali, and the formation of arsenic-alkali mixed salts with secondary pollution. In order to solve these problems, the leaching solution of arsenic-alkali residue (arsenic-alkali solution) was used as a raw material in this study, and a novel process of twice alkali recovery with CO 2 , deep alkali removal with H 2 SO 4 , As(V) reduction with SO 2 and evaporation concentration to recover arsenic was proposed to dispose of the arsenic-alkali solution. The total recovery of alkali was 87.8% by twice alkali recovery from the arsenic-alkali solution. After washing and thermal decomposition of crude NaHCO 3 , the obtained Na 2 CO 3 product can be used as the reagent of arsenic removal in the refining process of crude antimony. In the process of deep alkali removal, compared with the direct treatment, the consumption of H 2 SO 4 after twice alkali recovery was markedly reduced from the arsenic-alkali solution, and also no mirabilite was precipitated. The total recovery of arsenic was 80.6% in the process of arsenic recovery, and the purity of As 2 O 3 in arsenic trioxide product reached 95.2% after washing, which meets the third grade standard of arsenic trioxide (GB 26721–2011). This process realizes the efficient separation and recovery of arsenic and alkali from the arsenic-alkali solution, and also no arsenic-alkali mixed salts are produced. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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