氯化铵-氯化焙烧红土镍矿工艺及其热力学计算

Thermodynamics and chloridizing roasting conditions of laterite through ammonium chloride

通过对使用氯化铵焙烧法处理云南元江地区红土镍矿的相关化学反应进行热力学计算,并在此基础上研究氯化铵与红土镍矿质量比、焙烧温度、焙烧时间等工艺条件对红土镍矿氯化焙烧效果的影响。研究结果表明:随着焙烧温度的提高,镍、钴、锰的铁酸盐的氯化程度降低;而镍、钴、锰的硅酸盐和蛇纹石的氯化程度受焙烧温度的影响很小;镍、钴、锰、铁的氧化物除二氧化锰外,氯化程度均随焙烧温度提高而降低;当焙烧温度为673 K、焙烧时间为15 min、氯化铵与矿料质量比为0.8-1.0时,镍、钴、锰、铁、镁在常温下用水浸出5 min的浸出率分别为80%,60%,99%,58%和19%。

On the basis of thermodynamics with NH4Cl as chloridizing agent,the chloridizing roasting conditions of laterite obtained from Yunan Province including the mass ratio of NH4Cl/ore,roasting temperature and roasting time were researched.The results show that the chloride degree of ferrite of nickel,cobalt and manganese descends gradually with the increase of roasting temperature,the chloride degree of silicate of nickel,cobalt and manganese and serpentine are not influenced nearly by roasting temperature,and the chloride degree of oxide of nickel,cobalt,manganese and iron decreases with the increase of temperature besides manganese dioxide.The optimal conditions are as follows： roasting temperature is 673 K,roasting time is 15 min,the mass ratio of NH4Cl to ore is 0.8-1.0,the dissolution yields of nickel,cobalt,manganese,iron and magnesium using water as leaching reagent in 5 min at room temperature are 80%,60%,99%,58% and 19%,respectively.