陕西某含碳金矿氧化焙烧——提金试验研究  

Experimental Study on Oxidation Roasting-gold Extraction of a Carbon-bearing Gold Ore in Shaanxi Province

作　　者：郭守德 靳建平[1] 李艳军[1] GUO Shoude;JIN Jianping;LI Yanjun(School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110819

出　　处：《金属矿山》2025年第1期126-132,共7页Metal Mine

基　　金：国家自然科学基金面上项目(编号:5207041099)。

摘　　要：陕西某含碳金矿石金品位为3.29 g/t、碳含量为4.12%,自然金主要以显微金、细粒金形式被石英、褐铁矿等载金矿物包裹,包裹金占比达71.73%;矿石中石墨碳含量为0.94%、有机碳含量为1.30%,其余碳以碳酸盐形式存在。为了解决金的包裹和碳质物在浸金时的“劫金”现象,课题组开展了矿石悬浮氧化焙烧—浸金工艺研究,并进行了悬浮氧化焙烧对浸金效果改善的机理分析。结果表明,在给矿粒度-0.074 mm70%、氧气浓度20%、焙烧温度650℃、焙烧时间90 min条件下的脱碳率达98.23%;在液固比1.5∶1 m L/g、“金蝉”用量10 kg/t、浸出温度25℃、浸出时间12 h、搅拌转速300 r/min条件下的金浸出率达88.72%。悬浮氧化焙烧的积极意义在于:焙烧使白云母发生了脱羟基反应,白云石及方解石发生分解反应生成了氧化钙,硫化物发生了氧化裂解反应,其余碳质被氧化生成了二氧化碳而逃逸;焙烧使大量的包裹金变成了裸露-半裸露自然金。简而言之,矿石的悬浮氧化焙烧既使自然金充分暴露,又有效消除了“劫金”因素,因而有助于后续金的浸出。The carbon-bearing gold ore in Shaanxi has gold grade of 3.29 g/t,and carbon content of 4.12%.The natural gold is mainly in the form of microscopic gold and fine-grained gold wrapped by gold-carrying minerals such as quartz,limonite,etc.,and the proportion of the wrapped gold reaches 71.73%.The content of graphitic carbon in the ore is 0.94%,the content of organic carbon is 1.30%,and the rest of the carbon exists in the form of carbonate.In order to solve the problem of"gold robbing"phenomenon of gold parcels and carbonaceous material in the leaching of gold,the research group carried out the research on the process of ore suspension oxidation roasting-gold leaching,and carried out the mechanism analysis of the improvement of gold leaching effect by suspension oxidation roasting.The results showed that the decarburization rate reaches 98.23%under the conditions of feeding size of-0.074 mm accounting for 70%,oxygen concentration of 20%,roasting temperature of 650℃,and roasting time of 90 min.Under the conditions of a liquid-solid ratio of 1.5∶1 mL/g,an amount of"Jinchan"leaching agent of 10 kg/t,leaching temperature of 25℃,leaching time of 12 h,and stirring speed of 300 r/min,the gold leaching rate reaches 88.72%.The positive significance of suspension oxidation roasting lies in the following:roasting causes the dehydroxylation reaction of muscovite,the decomposition reaction of dolomite and calcite produces calcium oxide,the oxidative cracking reaction of sulfide occurs,and the rest of the carbon is oxidized to produce carbon dioxide and escape.Roasting makes a large number of wrapped gold into bare-semi-naked natural gold.In short,the suspension oxidation roasting of the ore not only fully exposes the natural gold,but also effectively eliminates the′gold robbery′factor,thus contributing to the subsequent leaching of gold.

关 键 词：含碳金矿石 微细粒包裹金 氧化焙烧 浸金 

分 类 号：TD923[矿业工程—选矿]