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本文简要概述含金物料(如原矿、精矿)氰化浸出中氧的作用。由于大部分金是以自然状态(Au°)存在,因此,金在氰化物浸出剂中溶解时的氧化至关重要。在高pH值下进行的氰化反应加入空气或氧气等弱氧化剂有利于自然金(Au°)的氧化。预先向待浸矿浆中充入空气或氧气除了促进金的氧化外,还可以减弱可溶性硫化物、砷化物、碲化物对金的氰化浸出的不利影响(即预充气工艺)。如果因金存在于硫化物、硅酸盐、碲化物等矿物中造成金的浸出困难,可以用氧化焙烧或加压氧化浸出的方法使金得到溶解。最近的文献资料表明,H_2O_2、NaO_2、CaO_2或O_3提供的活性氧可以使金在氰化过程中的氧化—氰化明显加快,并可在极短的时间内获得较高的浸出率。
This article briefly summarizes the role of oxygen in cyanide leaching of gold-bearing materials such as ore and concentrate. Since most of the gold is present in its natural state (Au °), the oxidation of gold when dissolved in a cyanide leaching agent is of crucial importance. The cyanidation reaction at high pH adds weak oxidizing agents such as air or oxygen to favor the oxidation of natural Au (Au). Pre-impregnation of air or oxygen into the slurry to be leached in addition to promoting the oxidation of gold, but also can reduce the adverse effects of soluble sulfide, arsenide, telluride cyanide leaching of gold (ie pre-aeration process). If gold is present in minerals such as sulfides, silicates, tellurides and the like, it is difficult to leach the gold, and gold can be dissolved by oxidation roasting or pressure oxidation leaching. Recent literature shows that reactive oxygen species provided by H 2 O 2, NaO 2, CaO 2 or O 3 can accelerate oxidation-cyanidation of gold during cyanation and obtain higher leaching rates in a very short period of time.