论文部分内容阅读
用氰化物处理了一种易处理金矿石。这种矿石含０．４％、以黄铜矿形式存在的铜。预浸出过程中，可溶性硫化物的氧化动力学不是处理时间长短的准确指标。只在使用氧气、硝酸铅和高浓度游离氰化物这样的特殊条件下，才能使金有效浸出。尽管在不降低提取率的情况下，氰化物的消耗不能降低到１．８５ｋｇ／ｔ以下，但如果添加硝酸铅则会得到较高的金提取率。不加硝酸铅时，金回收率低于９０％，而加硝酸铅，金回收率则达９８％。加入氧气，金回收率提高１．５％。当硝酸铅添加量高于３００ｇ／ｔ时，金提取率则不再增加。因此，在氰化的不同阶段，可以用氧化还原电位值作为硝酸铅添加量的控制参数来表示体系的状态。增加硝酸铅浓度会抑制黄铜矿的溶解，但使用这种方法不能充分有效地降低氰化物用量。溶液中的高浓度铜要求ＮａＣＮ浓度为７００ｍｇ／Ｌ。当平均ＮａＣＮ浓度低于６４０ｍｇ／Ｌ时，金回收率明显下降。也发现，在氰化开始时，可直接加硝酸铅，以获得与预浸过程中添加硝酸铅时相同的特性。
A cyanide-treated gold ore was treated. This ore contains 0.4% of copper in the form of chalcopyrite. During the pre-leaching process, the kinetics of the oxidation of soluble sulphides are not accurate indicators of the length of treatment. Only in the use of oxygen, lead nitrate and high concentration of free cyanide such special conditions, the gold can effectively leaching. Although cyanide consumption can not be reduced below 1.85 kg / t without lowering the extraction rate, higher gold extraction yields are obtained with the addition of lead nitrate. Without lead nitrate, the gold recovery rate is less than 90%, while adding lead nitrate, the gold recovery rate reached 98%. With oxygen, gold recovery increased by 1.5%. When the amount of lead nitrate is higher than 300g / t, the gold extraction rate will not increase. Therefore, in different stages of cyanidation, redox potential value can be used as the control parameter of the amount of lead nitrate to indicate the state of the system. Increasing the concentration of lead nitrate inhibits the dissolution of chalcopyrite, but the use of this method does not adequately and effectively reduce the amount of cyanide used. High concentrations of copper in the solution require a NaCN concentration of 700 mg / L. When the average NaCN concentration is lower than 640mg / L, the gold recovery rate is obviously decreased. It has also been found that at the beginning of cyanidation, lead nitrate can be added directly to obtain the same characteristics as when the lead nitrate was added during the prepreg.