The conversion of arsenic-containing waste residues into arsenic matte can be an important direction for arsenic treatment. In this paper, different parts of factory samples were first taken for study, and it was found that the leaching amount of arsenic at the chilling layer is noticeably low. Then, the effects of the cooling rate on the phase, microstructure, and chemical compositions and the subsequent toxicity leaching of the arsenic matte were studied. The results show that the alloy structure was obviously refined and the cavity size was also significantly reduced with an increase in cooling rate. Many large-strip FeS and arsenic-containing iron solid solutions were embedded in the matrix (Fe₂As) of the furnace-cooled and air-cooled samples; additionally, the Fe–As–S phase was probably caused by an insufficient phase separation of FeS from Fe₂As in the rapid cooling process of die cooling and water cooling. FeS in the factory samples was dissolved in the leaching solution, while Fe₂As could resist the corrosion of the leaching solution; therefore, it was speculated that the dissolution of arsenic was caused by the dissolution of FeS. The leaching mechanism was also discussed in this paper.

Graphic Abstract

The cooling rate affects phase, microstructure, and chemical compositions and toxicity leaching of the arsenic matte, which speculated that the dissolution of arsenic was caused by the dissolution of FeS

中文翻译：

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冷却速度对砷锍凝固组织和有毒浸出的影响

将含砷废渣转化为砷锍可以成为砷处理的重要方向。本文首先对工厂样品的不同部位进行了研究，发现冷冻层砷的浸出量明显偏低。然后，研究了冷却速度对砷锍的物相、微观结构和化学成分的影响以及随后的毒性浸出。结果表明，随着冷却速度的增加，合金组织明显细化，型腔尺寸也明显减小。许多大条状的 FeS 和含砷的铁固溶体嵌入基体中（Fe ₂As) 炉冷和风冷样品；此外，Fe-As-S 相可能是由于在模具冷却和水冷的快速冷却过程中FeS 与 Fe ₂ As 的相分离不充分所致。工厂样品中的FeS溶解在浸出液中，而Fe ₂ As可以抵抗浸出液的腐蚀；因此推测砷的溶解是由 FeS 的溶解引起的。本文还讨论了浸出机制。

图形摘要

冷却速率影响砷锍的物相、微观结构、化学成分和毒性浸出，推测砷的溶解是由FeS溶解引起的