复杂金精矿-NaOH-O_(2)系热力学分析及应用

Thermodynamic Analysis and Application of Complex Gold Concentrate-NaOH-O_(2) System

从热力学理论出发,模拟计算了碱矿比、富氧浓度、残氧率、焙烧温度等因素对某含多金属复杂金精矿金、银、铜提取的影响,并通过独立反应的热力学平衡关系确定物质之间的含量关系,从而确定了复杂金精矿氢氧化钠焙烧的反应机制。结果表明,焙烧最优条件为:碱矿比10%、富氧浓度25%、残氧率5%、焙烧温度630℃。通过正交试验对热力学条件进行验证,在最优条件下焙烧3h,焙砂进行硫酸浸出—氰化工序,在此条件下,金、银、铜的提取率分别为95.92%、84.24%、92.57%。

Based on thermodynamic theory,effects of alkali-ore ratio,oxygen concentration,residual oxygen rate,and roasting temperature on extraction of gold,silver,and copper from a complex gold concentrate containing multiple metals were simulated and calculated.Content relationship between substances through thermodynamic equilibrium relationship of independent reactions was determined.Reaction mechanism of sodium hydroxide roasting in complex gold ore was determined.The results show that the optimum roasting conditions include alkali-to-ore ratio of 10%,oxygen concentration of 25%,residual oxygen rate of 5%,and calcination temperature of 630℃.Thermodynamic conditions are verified by orthogonal experiment.Complex gold concentrate is roasted for 3 hunder the optimum conditions followed by sulfuric acid leaching-cyanide process.Under these conditions,extraction rates of gold,silver and copper are 95.92%,84.24%and 92.57%,respectively.