新型无氰浸出剂处理难浸金矿工艺与机理研究

发布时间：2019-05-27 12:34

【摘要】：氰化法浸金由于应用成熟、浸出简便,指标稳定等原因,一直为金矿浸出使用最多手段。然而,氰化法耗时久,具有剧毒性,对环境与操作员工造成了极大损伤。毒性低、效率高、便宜经济的非氰浸金手段一直都在被探索研究。本论文针对某高硫、砷难处理金矿,采用新型非氰浸出剂进行了浸金试验研究。试样工艺矿物学研究发现,其硫、铁元素占总量比为9.206%、12.694%,金品位为98.34g/t。矿石含砷,达2.7%。矿物组成简单,金属矿物主要为黄铁矿、金红石、毒砂,以及微量黄铜矿与闪锌矿、金矿物。脉石矿物主要为石英与长石,还有少量绢云母与绿泥石。金以不规则细脉或片状镶嵌在黄铁矿中,或以浸染状和毒砂致密共生,包裹在其中。矿样粒度较粗,-74μm仅占42.51%。金矿物与黄铁矿、毒砂集合紧密,属于高砷难处理硫化金矿。在探索试验基础上确定采用高温焙烧-酸性浸金方案。经过试验优化,最终确定的工艺参数为:原矿在750℃下焙烧2h,然后磨矿使得磨矿细度-0.037 mm含量占80.92%,采用浸出剂HJ-1用量0.8mol/L,氧化剂用量0.05mol/L,液固比4:1,浸出时间为3h,pH为2,搅拌转速600rad/min,在常温下进行浸出,最终获得金浸出率94.09%。热力学研究发现,在该浸出剂HJ-1的浸金系统中,Au主要以正三价被氧化,反应为复合离子Au(SCN)_4~-,在浸出反应过程中,溶液中不存在Au(SCN)_4~-及Au~+。且在HJ-1浸出系统中,SCN~-氧化分解不可避免。使用氧化剂氧化金矿时,也会氧化SCN~-,将SCN~-氧化为SO_4~(2-)、CN-以及H+。所以选择的氧化剂电极电势不应太高,应小于0.94-0.079pH-0.0074 logSCN~-/[SO_4~(2-)][OCN]~-。且对于使用Fe~(3+)作为氧化剂的HJ-1浸金体系,浸金溶液pH应该保持3以下。动力学研究发现,在浸出剂用量0.5~0.8mol/L,浸出温度15~45℃,氧化剂浓度0.02~0.05mol/L,浸出时间15~60 min的条件下,依据浸金数据可计算的表观活化能Ea为45.7kJ/mol,HJ-1反应级数为1.1,硫酸铁反应级数为0.5。由此可判断其浸金反应速率受化学反应模型控制。因此,使用该浸出剂处理该矿样的反应速率方程为:1-(1-η)~(1/3)=11.64e~(-45700/RT)?[HJ-1]~(1.1)?[Fe_2(SO_4)_3]~(0.5)。
[Abstract]:Cyanide leaching of gold has been the most widely used method for gold leaching because of its mature application, simple leaching and stable index. However, cyanide method takes a long time and is highly toxic, causing great damage to the environment and operators. Non-cyanide gold leaching methods, which are low toxicity, high efficiency and cheap economy, have been explored and studied all the time. In this paper, a new type of non-cyanide leaching agent was used to study the gold leaching of a refractory gold deposit with high sulfur and arsenic. It was found that the ratio of sulfur to iron was 9.206%, 12.694% and the grade of gold was 98.34 g 路t ~ (- 1), the ratio of sulfur to iron was 9.206%, 12.694%, and the grade of gold was 98.34 g / t. The ore contains 2.7% arsenic. The mineral composition is simple, the metal minerals are pyrite, rutile, arsenopyrite, as well as trace chalcopyrite and sphalerite, gold minerals. Gangue minerals are mainly quartz and feldspar, as well as a small amount of sericite and chlorite. Gold is inlaid in pyrite in irregular veinlets or flakes, or dense symbiosis in disseminated and arsenopyrite. The grain size of the ore sample is coarse, and the grain size of-74 渭 m is only 42.51%. Gold minerals and pyrite, arsenopyrite collection is close, belonging to high arsenic refractory sulphide gold deposits. On the basis of exploration and test, the scheme of high temperature roasting and acid leaching of gold was determined. After experimental optimization, the final technological parameters are as follows: the raw ore is calcined at 750 鈩，

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