Abstract Enargite ore (Cu3AsS4) is generally processed via pyrometallurgy, with high temperatures that release toxic arsenic (AsxOy) and sulfur (SOx) gases. In seeking alternatives that avoid production of noxious gases, this paper discusses batch leaching experiments of mineral mixtures of enargite and pyrite (Cu3AsS4 and FeS2), agitated under ammoniacal media (NH4OH) using sodium persulfate (Na2S2O8) as an oxidant. The results showed that almost complete leaching of enargite (98%) could be obtained due to the elimination of passivation (S°) by the action of the oxidant. With the help of a deep thermodynamic study and with DRX analysis, it was possible to establish the reaction mechanisms of dissolution of enargite with persulfate in an ammoniacal media. Leaching action selected for enargite, not affecting pyrite present. Enargite leaching can be represented under a heterogeneous kinetic model of reactant diffusion through a porous layer formed at reaction time. Orders of reaction 2.0 and 1.5, for persulfate and ammonium hydroxide concentrations, respectively, were established. Activation energy was calculated at 45.0 kJ/mol. Consecutive evaluations showed that metals present (Cu and As) could be precipitated with sodium sulfide and sodium hydrosulfide at 99% yields, thus generating a solution rich in ammonia that can be re-used in leaching.

中文翻译：

---

在氨介质下用过硫酸钠浸出 Enargite 并用 Na2S/NaHS 连续沉淀 As/Cu

摘要 Enargite 矿石 (Cu3AsS4) 通常通过高温冶金进行加工，高温会释放有毒的砷 (AsxOy) 和硫 (SOx) 气体。在寻找避免产生有毒气体的替代方案时，本文讨论了使用过硫酸钠 (Na2S2O8) 作为氧化剂在氨介质 (NH4OH) 下搅拌的 Enargite 和黄铁矿（Cu3AsS4 和 FeS2）矿物混合物的批量浸出实验。结果表明，由于氧化剂的作用消除了钝化（S°），可以获得几乎完全浸出（98％）的精钢。在深入的热力学研究和 DRX 分析的帮助下，可以建立 enargite 与过硫酸盐在氨介质中溶解的反应机制。为 enargite 选择浸出作用，不影响黄铁矿的存在。Enargite 浸出可以在反应物扩散通过在反应时间形成的多孔层的异质动力学模型下表示。分别为过硫酸盐和氢氧化铵浓度建立了反应顺序 2.0 和 1.5。活化能计算为 45.0 kJ/mol。连续评估表明，存在的金属（Cu 和 As）可以用硫化钠和硫氢化钠以 99% 的产率沉淀，从而产生富含氨的溶液，可在浸出中重新使用。