Abstract

A large amount of electric arc furnace dust (EAFD) is produced as hazardous waste materials during steelmaking in electric arc furnace. EAFD includes a considerable amount of zinc. Recovery of Zn as ZnO from EAFD via mechanochemical leaching, solvent extraction, precipitation, and thermal decomposition route was investigated. Dissolution behavior of Zn, Fe, Mn, Si, Mg, and Ca during the mechanochemical leaching of EAFD in H₂SO₄ solution was determined. Optimum mechanochemical leaching parameters were considered as 10 g of EAFD, 2 M H₂SO₄, 240 min of reaction time, ball to the dust weight ratio of 20, and rotational speed of 500 rpm. D2EHPA solution (20%, vv) was used for solvent extraction of Zn from mechanochemical leach solution. McCabe–Thiele diagrams constructed for extraction and stripping stages indicated that 95% of zinc in the leach solution was extracted in three stages at A:O = 1:1, while 97% of Zn was stripped from loaded organic phase at operating line of A:O = 4:1. ZnC₂O₄∙2H₂O powder was precipitated from strip solution obtained by solvent extraction by adding oxalic acid solution at pH 4. Thermal properties of ZnC₂O₄·2H₂O precipitated were investigated by thermogravimetric–differential thermal analysis technique. High-purity ZnO was obtained by thermal decomposition of ZnC₂O₄∙2H₂O precipitated.

Graphical Abstract

中文翻译：

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通过机械化学浸出，溶剂萃取，沉淀和热分解途径从炼钢废料中回收Zn作为ZnO。

摘要

电弧炉炼钢过程中会产生大量的电弧炉粉尘（EAFD）作为有害废料。EAFD包含大量的锌。研究了通过机械化学浸出，溶剂萃取，沉淀和热分解途径从EAFD中回收ZnO形式的ZnO。确定了EAFD在H ₂ SO ₄溶液中进行机械化学浸出过程中Zn，Fe，Mn，Si，Mg和Ca的溶解行为。最佳机械化学浸出参数为10 g EAFD，2 MH ₂ SO ₄，反应时间为240分钟，球与粉尘的重量比为20，转速为500 rpm。D2EHPA溶液（20％，vv）用于从机械化学浸提溶液中萃取锌。McCabe–Thiele的萃取和汽提阶段图表明，浸出溶液中95％的锌在A：O = 1：1的三个阶段中被萃取，而97％的Zn在A操作线从负载的有机相中汽提：O = 4：1。长于氯化锌₂ ø ₄ ∙2H ₂ O粉末是通过在pH加入的草酸溶液4.长于氯化锌的热性能通过溶剂萃取从所得条带中沉淀₂ ö ₄ ·2H ₂通过热重-差热分析技术研究了析出的O。通过热分解析出的ZnC ₂ O ₄ ∙2H ₂ O获得高纯度ZnO 。

图形概要