难选金矿微波预处理边磨边浸非氰化试验研究

摘要

某难选金矿石化学成分分析结果显示，金品位为3.51×10-6，SiO2含量高达71.88%，有害元素为碳和硫。其中，有机碳含量高达2.51%，严重阻碍了后续浸出过程的进行。 XRD 和金物相分析可知，矿石中主要矿物为石英、方解石及硫化矿，硫化矿以黄铁矿为主。金主要以微细粒浸染或包裹于石英、硅酸盐、硫化矿及碳酸盐矿物中。针对该难选金矿石的性质，采用非氰化药剂 TL 直接浸出时，浸出率较低。采用了微波预处理边磨边浸非氰化工艺，研究了微波焙烧时间、微波焙烧温度、浸出剂 TL 的用量、液固比及磨浸时间对金浸出率的影响。试验结果表明，在微波焙烧温度为650℃、微波焙烧时间为45 min 的条件下，当非氰化浸出剂用量为6 kg/t、液固比为4∶1、磨浸时间为6 h 时，可获得71.64%的金浸出率。%The analysis results of ore chemical composition at a certain refractory gold demonstrated that the gold grade was around 3.51 ×10-6,content of SiO2 was as high as 71.88% ,harmful element was mainly with the presentation of organic carbon and sulfur.In addition,the content of organic of carbon even reached up to 2.51%, which hampered the following leaching procedure seriously.After analyzing the XRD and phase of gold,it was found that the ore main minerals were primary composed with quartz,calcite and sulfide ore,while sulfide ore was given priority to with pyrite.According to the characters of refractory gold ore,when employing the cyanide reagent TL to leaching directly,low leaching rate can be obtained.Therefore,we used microwave method for pretreatment with grinding and leaching simultaneously without cyaniding,and paid attention to the microwave roasting time,microwave roasting temperature,the amount of leaching agent TL,liquid-solid ratio,and the impact of mill leaching time on the gold leaching rate.The results showed under the conditions that microwave roasting temperature at 650 ℃,and microwave baking time of 45 min,the gold leaching rate of 71.64% was achieved when a non-cyanide leaching dosage was 6 kg/t,liquid to solid ratio was about 4∶1,and grinding time was 6 h.