含银难处理金精矿焙烧过程添加剂的研究和应用.docVIP

含银难处理金精矿焙烧过程添加剂的研究及应用 (紫金矿业集团股份有限公司，低品位难处理黄金资源综合利用国家重点实验室，福建上杭 364200） 摘要：针对含银难处理金精矿，研究焙烧过程添加剂种类及其用量、焙烧工艺主要参数包括温度、时间等对金、银、铜浸出率的影响，并对焙烧反应热力学及银物相进行分析。结果表明，添加2%氢氧化钠作为添加剂，焙烧温度650 ℃、焙烧时间2 h，银浸出率由43.62%显著提高至75.65%，金、铜的浸出率亦有不同程度提高，其浸出率分别为91.73%、92.50%。焙烧反应热力学及银物相分析表明，加入氢氧化钠焙烧可降低硅酸盐对银的包裹。生产实践表明，焙烧过程添加氢氧化钠作为添加剂可取得良好技术经济指标。 关键词：焙烧；添加剂；浸出率；难处理金精矿；银物相 中图分类号：TF821 文献标志码：A 文章编号：1007-7545（2016）01-0000-00 and Application of Additive in Roasting Process for Silver Bearing Refractory Gold Concentrates ZHONG Shui-ping (Zijin Mining Group Co., Ltd, State Key Laboratory of Comprehensive Utilization of Low-grade Refractory Gold Ores, Shanghang 364200, Fujian, China) Abstract: The effects of type and dosage of additive, roasting temperature and duration on leaching rates of gold, silver and copper were investigated in treating process of silver-bearing refractory gold concentrates. In addition, the thermodynamics of roasting reaction and silver phase were analyzed. The results show that leaching rate of silver is improved from 43.62% without NaOH addition to 75.65% with NaOH dosage of 2% when roasting temperature is 650 ℃ and roasting time is 2 h. The leaching rate of gold and copper is also improved in varying degrees, which is 91.73% and 92.50% respectively. The analysis of thermodynamics of roasting reaction and silver phase shows that adding NaOH can reduce the silicate bound for silver. The industrial practice shows that with addition of NaOH as additive in roasting process of silver bearing refractory gold concentrates can achieve good technical-economic indexes. Key words: roasting; additive; leaching rate; refractory gold concentrates; silver phase 难处理金矿是目前黄金工业的主要资源。工业上应用的主要工艺[1-3]有焙烧预氧化—氰化、生物预氧化—氰化和热压预氧化—氰化。其目的是使载金矿物（主要为黄铁矿、磁黄铁矿）在一定条件下氧化，使金及其可能伴生的银、铜等矿物的包裹体打开、暴露，利于后续浸出。焙烧预氧化—氰化工艺具有对矿物适应性强、处理能力大、易于操作等优点而被普遍采用。但该工艺国内外公认的亟需解决的难题是伴生银回收率低（普遍60%以下）。 为解决银回收率低的难题，科研人员开展了大量研究工作，主要集中[4-9]在焙烧工艺中添加各种添加剂，包括氢氧化钠、硫化钠、碳酸钠、石灰及其它新型添加剂等。研究结果表明，通过添加上述添加剂能不同程度地提高金、银浸出率，对提高银浸出率效果更为明显。但上述研究基本为实验室研究，