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常温下,使用几种氧化剂(次氯酸盐、碘、H_2O_2)来促进金在碘电解质溶液中的溶解。由溶金过程的两个半电池反应绘制而成的伊文斯图可以看出:对于碘化物提金系统来说,H_2O_2并不是一种合适的氧化剂。金在I_2-I~-混合溶液中的溶解速度决定于I_2、I~-的浓度及溶液的pH值。当〔KI〕=0.1M时,pH值为2.7到11.5的范围内,I_2/I~-的最佳摩尔浓度比为0.35～0.4之间。在此最佳条件下,金的溶解速度可以达到最大值17mg/cm~2·h。如果加入少量的次氯酸盐(<0.025M),金的溶解比加碘时更快。在OCl~--I~-的混合溶液中金的溶解强烈地决定于溶液的pH值,在pH=2.7、〔KI〕=0.02～0.1M时,最佳的OCl~-/I~-的摩尔浓度比为0.25。而使用同浓度的氰化法,金的溶解速度在1.3(pH=12.5)和3.5(pH=8.5)mg/cm~2·h之间。
At room temperature, several oxidants (hypochlorite, iodine, H 2 O 2) are used to promote the dissolution of gold in the iodine electrolyte solution. Evans Figure drawn from the two half-cell reactions of the gold dissolution process shows that H 2 O 2 is not a suitable oxidant for the iodide gold extraction system. The dissolution rate of gold in I_2-I ~ - mixed solution depends on the concentration of I_2, I ~ - and the pH of the solution. When [KI] = 0.1M, the optimum molar ratio of I_2 / I ~ - was between 0.35 and 0.4 in the range of 2.7 to 11.5. Under the optimal conditions, the dissolution rate of gold can reach the maximum 17mg / cm ~ 2 · h. If a small amount of hypochlorite (<0.025M) is added, the dissolution of gold is faster than when iodine is added. The dissolution of gold in the mixed solution of OCl ~ - I ~ - is strongly determined by the pH of the solution. The best OCl ~ - / I ~ - at pH = 2.7 and [KI] = 0.02 ~ 0.1M The molar ratio is 0.25. With the same concentration of cyanidation, the dissolution rate of gold was between 1.3 (pH = 12.5) and 3.5 (pH = 8.5) mg / cm ~ 2 · h.