微生物捕收剂浮选微细粒黄铜矿过程中的界面调控机制研究

The efficient recovery of micro-particles of useful minerals is a technical problem belongs to mineral processing domain. Microbial technology is applied in micro-particle flocculation and adsorption of heavy metals in wastewater, provide a new idea for the recovery of micro-grained minerals. In this project, the micro-grained chalcopyrite is taken as the research object. The microbial collector, with high charge capacity and strong hydrophobicity and special effect on the flotation of fine grained chalcopyrite, was screened out by using the unique interfacial properties of the microorganisms. The sorption characteristics of microbial collectors onto micro-grained chalcopyrite interfaces were investigated to reveal the adsorption mechanism. The flotation behavior of fine-grained chalcopyrite, the interaction among mineral particles and the hydrophobic flocculation behavior under the system of microbial collector induction were systematically investigated. And the mechanism of aggregation and dispersion of micro-grained chalcopyrite under the microbial collector flotation system and the formation of hydrophobic aggregates were clearly identified. The surface hydrophobicity and electric potential of the chalcopyrite particles were improved through the surface groups of the microbial collector. Then adjust surface properties of the microorganisms and the conditions of the pulp slurry to form the selective adsorption microorganisms for the chalcopyrite. It can strengthen the flotation process of chalcopyrite hydrophobic floc, form a new technology prototype of microbial collector to enhance the fine-grained chalcopyrite flotation. Thus, the high efficiency recovery of micro-grained chalcopyrite is realized, which provides a reference for the efficient utilization of micro-grained mineral resources.

微细粒有用矿物高效回收是矿物加工领域亟待解决的技术难题，微生物技术在微细粒絮凝和吸附废水中重金属离子等领域的应用，为此类资源的回收提供了新思路。本项目以矿浆中微细粒黄铜矿为研究对象，利用微生物独特的界面性质，筛选出荷电量高和疏水性强、对微细粒黄铜矿浮选具有特效的微生物捕收剂；研究微生物捕收剂与微细粒级黄铜矿的界面吸附特征，揭示微生物捕收剂在黄铜矿表面的吸附机理；系统考察在微生物捕收剂诱导体系下细粒黄铜矿的浮选行为、矿物颗粒间相互作用和疏水絮团行为，明晰微细粒级黄铜矿在微生物捕收剂浮选体系中聚集/分散行为和形成疏水聚团的机理；通过微生物捕收剂表面基团改变黄铜矿颗粒表面的疏水性和电位，调控微生物表面性能和矿浆环境形成黄铜矿选择性吸附微生物捕收剂的条件，强化黄铜矿疏水絮团浮选过程，形成微生物捕收剂强化微细粒级黄铜矿浮选的新技术原型，实现微细粒级黄铜矿高效回收，为微细粒矿产资源的高效利用提供借鉴。

微细粒有用矿物高效回收是矿物加工领域亟待解决的技术难题，微生物技术在微细粒絮凝和吸附废水中重金属离子等领域的应用，为此类资源的回收提供了新思路。本项目以微细粒黄铜矿为研究对象，进行了不同粒级的黄铜矿制备、界面性质及浮选行为；微生物捕收剂的分离、培养、筛选及鉴定；微生物对黄铜矿、辉钼矿浮选分离的影响；微生物与微细粒级黄铜矿的界面吸附特征等方面的研究。筛选了从德兴铜矿某采矿土壤、坑道水以及赣州某地土壤中共分离出得到84株细菌，利用“培养-离心-分散再离心-冷冻干燥-制粉”方法将细菌制成抑制剂对黄铜矿等硫化矿物进行浮选，筛选出1株对辉钼矿有明显抑制作用的细菌，结合细菌形态特征分析和16S rDNA序列测定鉴定结果为热带芽孢杆菌（Bacillus tropicus）。在单矿物浮选试验中，发现过量的热带芽孢杆菌会抑制黄铜矿、方铅矿、闪锌矿和辉钼矿的上浮，且回收率均低于40%，而热带芽孢杆菌抑制剂用量在10mg/L，pH值=9.0时，最终得到黄铜矿的回收率为74.10%，辉钼矿的回收率为20.47%。通过测试黄铜矿、辉钼矿与热带芽孢杆菌作用前后的接触角、 Zeta电位，发现热带芽孢杆菌对黄铜矿、辉钼矿的表面性质均有较大改变；在热带芽孢杆菌作用后的辉钼矿DSC曲线出现了新的放热峰表明其对辉钼矿烧失曲线的改变；扫描电镜下的辉钼矿表面在与热带芽孢杆菌作用后附着了不规则碎片、芽孢等物质，在EDS能谱图下，附着的碎片中C元素含量增加从33.87%上升到64.69%；在红外光谱的检测下，热带芽孢杆菌作用后的辉钼矿表面出现了热带芽孢杆菌细胞中携带的蛋白质、糖类大分子才有的-OH吸收峰（3559.56cm-1），双键（-C=C-和-N=N=）伸缩振动吸收峰（1628.58cm-1）， -NO2吸收峰（1527.16cm-1）。本项目的研究结果可为形成微细粒级黄铜矿浮选新技术提供理论基础，为微生物作为矿物浮选药剂实现开发环保绿色药剂提供了研究方法，对微细粒级矿物的浮选和高效回收具有重要的理论价值和实际指导意义。