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本文简要论述了金矿物(例如矿石、精矿)氰化浸出中氧的作用。大多数的金以元素状态(Au°)出现,因此金的氧化对金在氰化物浸出液中溶解是极为重要的。在高pH值下氰化有利于用弱氧化剂如空气或氧来氧化Au。此外,只要预先向浸出矿浆中通入空气或氧(即预通空气过程),还可减缓溶解的硫化物、砷酸盐、锑酸盐对金氰化的有害作用。 如果金由于封闭在硫化物、硅酸盐、碲化物等化合物中而难以处理,那么在氧存在的条件下焙烧或在氧压下浸出都可将金释放出来。最近文献中数据表明,在氰化过程中由H_2O_2、Na_2O_2、CaO_2或O_3所提供的活性氧可大大加快金的氧化过程,并且在短得多的浸出时间内产生很高的金回收率。本文列举的信息得出如下结论:氧在氰化浸出的溶解过程中,起着极为重要的作用。
This article briefly discusses the role of oxygen in cyanide leaching of gold minerals (eg, ores, concentrates). Most of the gold appears in the elemental state (Au °), so gold oxidation is extremely important for the dissolution of gold in the cyanide leach solution. Cyanation at high pH favors the oxidation of Au with weak oxidants such as air or oxygen. In addition, as long as air or oxygen is introduced into the leached slurry in advance (ie, the pre-air process), the harmful effects of dissolved sulfides, arsenates and antimonates on cyanidation can also be mitigated. If gold is difficult to handle because it is trapped in compounds such as sulfides, silicates, tellurides, etc., gold can be released by calcination in the presence of oxygen or by leaching at oxygen pressure. Recent literature data show that reactive oxygen species provided by H 2 O 2, Na 2 O 2, CaO 2 or O 3 during cyanidation can greatly accelerate the gold oxidation process and produce a high gold recovery over a much shorter leaching time. The information presented in this paper leads to the conclusion that oxygen plays an extremely important role in the dissolution of cyanide leaching.