氰化提金及氧化剂强化浸金过程机理研究

研究了黄铁矿氰化剂提金过程,以及氰化钠浓度、浸出温度和氧化剂等对金浸出率的影响,研究了氧化剂强化浸金过程的机理。结果表明:常温时,在双氧水做氧化剂的前提下,氰化钠浓度0.05%,浸出时间12 h,金的浸出率可达94%以上。

过氧化钙氧缓释剂制备及其强化浸金过程研究

为延长过氧化钙释氧时间,且避免直接使用过氧化钙粉末造粒过程中与水接触影响释氧效果,或引入其它包埋材料导致污染。以氧化钙、过氧化氢为主要原料,采用新工艺直接制备过氧化钙氧缓释剂,用于难浸金矿的强化浸出,探究其强化浸金过程。结果表明,反应时间为70 min,过氧化氢添加量为22 mL,盐酸添加量为0.8 mL条件下,可以制备出过氧化钙含量为54.32%、粒度为5 mm的氧缓释剂。在浓度为300 mg/L的氰化钠溶液中添加4g/L的氧缓释剂,经40 d后溶解氧浓度仍可提高2.04 mg/L。50 kg矿样柱浸试验结果显示,在矿石金品位为0.51 g/t、浸金剂中氰根离子浓度为300 mg/L条件下,添加0.8 g/kg过氧化钙氧缓释剂浸出40 d,浸出率比空白组提高了10.73个百分点,氰化钠的消耗量降低了25.3%,贵液中溶解氧浓度可提高0.5~1 mg/L。表明添加过氧化钙氧缓释剂可以有效解决大型堆浸矿山因内部氧亏导致的浸出率低的问题。

某难处理含金硫精矿强化浸金试验研究

针对云南某难处理含金硫精矿硫含量高,直接氰化浸出金回收率低等问题,进行了再磨再浸-活化剂活化-碱预处理新工艺探索试验研究。结果表明:在磨矿细度-0.043 mm占98%,石灰用量16 kg/t,搅拌速度1 200 r/min,液固比2∶1,氰化钠用量7 kg/t,硝酸铅用量500 g/t,碱预处理时间4 h,氰化浸出36 h的最佳条件下,获得了较好试验指标,金浸出率达71.90%,较直接氰化浸出提高37.09百分点。

非氰浸金剂的研究进展与展望

随着国家对企业绿色生产要求的提高,传统氰化法浸金工艺的劣势愈加明显,无法满足当前的环保要求。在浸金领域,亟需寻找一种能替代氰化物的非氰浸金剂。本文对非氰浸金剂进行了分类总结,更新了传统浸金剂(含硫浸金剂、卤化物浸金剂、微生物、氨基酸等)的研究与应用进展;综述了目前热度较高的新型环保合成浸金剂的合成方法与研究现状;除单一成分的浸金剂外,本文还对多种不同浸金剂组成的共强化体系进行了系统总结,为非氰浸金剂领域的学者提供了重要的参考。

Co-intensification of cyanide leaching gold by mercury ions and oxidant

The effects of mercury ions on gold cyanidation were studied. The results show that under low cyanide concentration, gold cyanide process is controlled by CN- transfer, while at higher cyanide concentration, there forms passivation on gold surface. Therefore, chemical oxidation of gold in cyanide solution of higher concentration is controlled by surface reaction. Small quantity of additions of mercury ions bring about great increases in anodic gold dissolution rate, decreases the passivation and reduces the equilibrium activated energy. In addition, they also markedly change the effect pattern of cyanide concentration. Mercury ions show positive effects on cathodic reduction of oxygen and raise the rate of electrochemical step of the cathodic reduction of oxygen. Addition of a certain amount of hydrogen peroxide is confirmed to be an effective way for intensification of cathodic process on gold electrode. Active potential range and current peak on anodic dissolution are enlarged when being co-intensified with Hg^2＋ and hydrogen peroxide. Co-intensifying effect may be obtained and gold from gold concentrates. gold leaching rate is considerably increased on cyanide leaching of