Cyanidation has long served as the industrial standard in the gold industry, necessitating heightened attention to cyanide management owing to its inherent toxicity. This study developed a novel MnO-assisted thiocyanate leaching system as an alternative to cyanide. The sample was generated from a refractory gold concentrate processed by roasting, containing 54.4 g/t gold with iron oxide and quartz as the major mineral phases. Within the framework of the novel system, gold recovery was investigated in terms of gold association, recovery behavior, thermodynamics, and optimization using cyclic extraction protocols. The most suitable leaching conditions were determined as 1.20 mol/L NaSCN, 4.00 mmol/L MnO, pH at 1.00, liquid-to-solid ratio of 4 mL/g, and leaching duration of 24 h, resulting in a maximum gold extraction of 94.8%. Subsequent zinc precipitation facilitated a gold recovery of 99.4% from the leachate. Furthermore, the implementation of a cyclic extraction scheme, coupled with reagent addition to offset consumption, yielded a significant thiocyanate dosage reduction by 75% while maintaining gold recovery. This acidic leaching system yields satisfactory gold recovery with minimized reagent consumption, particularly suited for refractory gold ore that has undergone acidic pretreatment.

中文翻译：

---

MnO2辅助硫氰酸盐浸出和锌粉胶结循环萃取从焙烧难熔金精矿中回收金


氰化长期以来一直是黄金行业的工业标准，由于其固有的毒性，需要高度重视氰化物的管理。本研究开发了一种新型 MnO 辅助硫氰酸盐浸出系统作为氰化物的替代品。样品由难熔金精矿经焙烧加工而成，含金54.4克/吨，以氧化铁和石英为主要矿相。在新系统的框架内，从金缔合、回收行为、热力学和使用循环萃取方案的优化方面研究了金回收。确定最佳浸出条件为NaSCN 1.20 mol/L、MnO 4.00 mmol/L、pH 1.00、液固比4 mL/g、浸出时间24 h，金提取量最大为94.8%。随后的锌沉淀促进了从浸出液中回收 99.4% 的金。此外，实施循环萃取方案，加上添加试剂以抵消消耗，使硫氰酸盐剂量显着减少了 75%，同时保持了金回收率。该酸性浸出系统以最小化试剂消耗获得令人满意的金回收率，特别适合经过酸性预处理的难熔金矿石。