微细浸染型金矿非氰浸出试验研究

发布时间：2019-02-15 18:10

【摘要】：微细浸染型金矿作为一种难处理金矿,是我国的主要黄金资源之一。加强对微细浸染型金矿的开发和利用,具有十分重要的意义。论文以贵州某微细浸染型金矿为研究对象,在矿石性质研究基础上,开展非氰浸出试验研究。通过非氰方法研究、预处理方法研究和预处理-非氰浸出优化试验研究确定合适的工艺流程和较佳的试验条件,采用不同测试手段对原矿、预处理样和浸渣进行对比分析,并从溶液化学反应和热力学角度对预处理和浸金体系进行机理探讨。通过多元素、矿物组成、金的化学物相、扫描电镜和粒度组成分析研究矿石性质,表明矿石中金是主要有用元素,品位为3.46 g/t,银、铜、铅、锌、锑和砷含量低,含有一定量有机碳。矿石主要由石英、方解石、黄铁矿和粘土矿物组成。金呈分散分布,单体解离和连生金、硫化物、硅酸盐和碳酸盐包裹金分布率分别为22.96、34.24、23.73和19.07%。金分布不均匀,主要分布在较粗粒级和细粒级中。说明很难通过单一方法提高金回收率,各包裹体中金的暴露是有效浸金的关键。根据矿石性质研究结果,选择JQ、硫代硫酸盐、硫氰酸盐以及SZS四种非氰试剂在常温常压下进行直接浸金探索试验研究,综合考虑选择SZS为浸金药剂,SZS直接浸金率最高为60.53%。在浸出方法研究的基础上,选择常规焙烧、强氧化预处理、强碱性预处理和M-1+M-3预处理四种方法进行原矿预处理试验研究,综合考虑选择M-1+M-3预处理方法。通过M-1+M-3预处理-SZS浸出工艺的优化试验研究得出较佳的工艺为常温常压预处理后不脱药直接常温常压浸出,较佳条件为:预处理过程M-1和M-3用量分别为50和105 kg/t,充气量为1.8 m3/h,液固比为2:1,常温搅拌24 h,浸出过程SZS浓度4.4%,催化剂Cu2+和NH3·H2O浓度分别为0.06 mol/L和1 mol/L,稳定剂Na2SO3浓度为0.15 mol/L,矿浆液固比为3:1,pH为11,常温搅拌浸出4 h。混合浸出剂稳定性较好,保质期为10天左右,在此条件下金浸出率在84%~86%。采用XRD、XRF、物相分析、扫描电镜、Raman和XPS等手段对原矿、预处理样和浸渣进行对比分析,得出经过预处理和浸出后,矿物表面O、Si、Ca、Fe和S元素的化学环境发生了变化。预处理后Si、S含量降低,预处理作用使部分SiO2发生溶蚀,黄铁矿被氧化成Fe2O3和SO42-,预处理后硅酸盐、黄铁矿中金分布率降低,单体解离金和连生金、碳酸盐中金分布率增大,说明经过预处理,大部分硫化物和硅酸盐中金被暴露或解离成游离金,但新生成的碳酸盐又重新包裹了金。通过预处理过程化学反应吉布斯自由能?G和Eh-pH图的分析,表明溶液中存在氧化剂,反应时间足够长时,大多数黄铁矿最终会被氧化成Fe2O3和SO42-;溶液的pH环境和离子强度显著影响着石英的溶解,较高pH条件有利于石英的溶解,SiO2的溶解受溶液中物质扩散影响小,主要受化学反应的限制。从溶液化学反应和热力学角度对SZS-铜-氨体系进行了机理探讨,表明SO32-有助于S2O32-的稳定,但也会加速Sx2-反应生成S2O32-。溶液中pH值、Cu(NH3)42+和SO32-浓度直接和间接地影响着浸金效果。
[Abstract]:The fine-disseminated gold deposit is one of the main gold resources in China as a kind of hard-to-treat gold mine. It is of great significance to strengthen the development and utilization of the micro-disseminated gold deposit. In this paper, a study on non-cyanide leaching is carried out on the basis of the study of the ore properties of a fine disseminated gold deposit in Guizhou. Through the study on the non-cyanide process, the pretreatment method and the pretreatment-non-cyanide leaching optimization test, the appropriate process flow and the better test conditions are determined, and the raw ore, the pretreatment sample and the leaching residue are compared and analyzed by different test methods. The mechanism of pretreatment and gold-leaching system is discussed from the chemical reaction and the thermodynamic angle of the solution. The properties of the ore were studied by multi-element, mineral composition, chemical phase of gold, scanning electron microscope and particle size composition. It is indicated that gold in the ore is the main useful element. The grade is 3.46 g/ t, and the content of silver, copper, lead, zinc, antimony and arsenic is low and contains a certain amount of organic carbon. The ore is mainly composed of quartz, calcite, pyrite and clay minerals. The distribution rate of gold, sulfide, silicate and carbonate was 22. 96, 34. 24, 23. 73 and 19. 07%, respectively. The distribution of gold is not uniform, and is mainly distributed in the coarse and fine-grained grades. It is difficult to improve the recovery rate of gold by a single method, and the exposure of gold in each package is the key to the effective gold leaching. Based on the results of the study on the properties of the ore, four non-cyanide reagents, such as JQ, thiosulphate, thiocyanate and SZS, were selected for direct gold leaching in normal temperature and normal pressure. On the basis of the research of the leaching method, four methods, such as conventional roasting, strong oxidation pretreatment, strong alkaline pretreatment and M-1 + M-3 pretreatment, are selected to carry out the pretreatment test of the raw ore, and the M-1 + M-3 pretreatment method is comprehensively considered. The optimum process of the pretreatment with M-1 + M-3 pretreatment-SZS leaching process is as follows: the pretreatment process M-1 and M-3 are respectively 50 and 105 kg/ t, the aeration amount is 1. 8m3/ h, the liquid-solid ratio is 2: 1, The concentration of Cu 2 + and NH3 路 H2O at room temperature is 4. 4%, the concentration of the catalyst Cu2 + and NH3 路 H2O is 0.06mol/ L and 1mol/ L, the concentration of the stabilizer Na2SO3 is 0. 15mol/ L, the solid ratio of the ore slurry is 3: 1, the pH is 11, and the leaching is carried out at normal temperature for 4 h. The stability of the mixed leaching agent is good, and the shelf life is about 10 days. Under this condition, the leaching rate of gold is 84% ~ 86%. The chemical environment of O, Si, Ca, Fe and S elements in the mineral surface was changed by means of XRD, XRF, phase analysis, scanning electron microscope, Raman and XPS. The chemical environment of O, Si, Ca, Fe and S elements in the mineral surface was changed after pretreatment and leaching. after the pretreatment, the content of Si and S is reduced, the pre-treatment effect causes the partial SiO2 to be eroded, the pyrite is oxidized into Fe2O3 and SO42-, the gold distribution rate of the pre-treated silicate and the pyrite is reduced, the gold distribution rate of the monomer is increased, and the description is subjected to pretreatment, Most of the sulfides and silicates are exposed or dissociated into free gold, but the newly formed carbonate is re-wrapped with gold. Free energy of Gibbs free reaction through pretreatment process? The analysis of G and Eh-pH maps shows that when the oxidizing agent is present in the solution and the reaction time is long enough, most of the pyrite is finally oxidized to Fe2O3 and SO42-; the pH environment and the ionic strength of the solution greatly influence the dissolution of the quartz, and the higher pH condition is beneficial to the dissolution of the quartz, The dissolution of SiO2 is affected by the diffusion of the substance in the solution, which is mainly limited by the chemical reaction. The mechanism of SZS-Cu-ammonia system is discussed from the chemical reaction and the thermodynamic angle of the solution, which shows that SO32-can help the stability of S2O32-, but also accelerate the Sx2-reaction to generate the S2O32-. The pH value, Cu (NH3) 42 + and SO32-concentration in the solution directly and indirectly affect the gold leaching effect.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD953

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