某浮选金精矿微波低温预处理助浸试验

为了揭示微波低温预处理对硫化物包裹的微细粒分散金的助浸效果，以福建双旗山浮选金精矿为原料，以微波低温预处理为核心手段，研究了不同助浸条件对金浸出的影响。结果表明，在微波功率为3 kW、预处理时间为6 min（对应的预处理温度为300 ℃左右），焙渣磨矿细度为-0.038 mm占80%，氰化钠用量为3 kg/t、浸出时间为8 h情况下，金浸出率达到96.49%，高于相应条件下马弗炉低温预处理时金浸出率4.17个百分点；与强氧化剂助浸相比，因为微波低温预处理改变的是矿石的微观结构，而强氧化剂改善的只是浸出过程中溶解氧的浓度，因而微波低温预处理的浸出率要高约2个百分点；微波低温预处理助浸与其他助浸方式比较，可以提高金浸出率、缩短浸出时间。

Experiment of Microwave Low-temperature Pretreatment Aid-leaching on a Gold Concentrate from Flotation

In order to illustrate the aid leaching effect of microwave low temperature pretreatment on fine scattered gold wrapped by sulfide，the effects of various aid-leaching conditions on gold leaching efficiency was researched with gold concentrate of flotation from Shuangqishan，Fujian，as raw materials，and the microwave low temperature pretreatment as the key method.The results showed that with the microwave pretreatment power of 3 kW，the time of microwave pretreatment for 6 min(the corresponding pretreatment temperature is nearly 300 ℃)，particle size of roasting slag of 80% passing 0.038 mm，dosage of sodium cyanide of 3 kg/t，leaching for 8 h，gold leaching rate reached 96.49%，and 4.17 percentage points higher than that with related conditions roasted in muffle furnace.Compared with strong oxidants aid-leaching，the leaching rate pretreated by microwave low temperature is 2 percentage points higher，since the microwave low temperature pretreatment changes the structure of ore，while the strong oxidants only ameliorate the concentration of dissolved oxygen in leaching process.Compared with other aid-leaching methods，the microwave low temperature pretreatment can increase gold leaching rate，shorten length of leaching time.