大厂老尾矿综合回收关键技术研究

【作者】 王雅静；

【导师】 张宗华；

【作者基本信息】 昆明理工大学 ， 矿物加工工程， 2008， 博士

【摘要】 本课题来源于国家十五重点科技攻关项目“铜、铅、锌、锡尾矿开发利用产业化关键技术研究”（编号2003 BA612A-18），该专题目的是综合回收尾矿中的有价成分。广西大厂的锡石-多金属硫化矿石属于典型的复杂难选硫化矿，目前，大厂多金属硫化矿产生的尾矿已堆积近三千万吨，内含丰富的锡、铅、锌、锑金属及硫、砷。由于受当时技术水平和生产条件的限制，回收的金属技术指标较低。很多金属特别是细粒级金属在尾矿中损失严重，尾矿中还有许多有用矿物没有得到回收。这些尾矿的流失既造成资源的浪费，又构成了污染大厂矿山外部环境的隐患。随着大厂资源日益贫化，大规模生产不断进行，在开采原生矿的同时，对尾矿进行二次开发利用，综合回收其中的多种有价元素，可产生极为可观的经济效益和社会效益，具有重要意义和价值。本研究针对大厂矿区多金属硫化矿尾矿的综合回收，详尽考察了脆硫锑铅矿、铁闪锌矿、黄铁矿和毒砂的浮选性能，通过吸附量测定、ξ电位测定及红外光谱分析检测矿物表面成分，探讨了四种矿物浮选分离机理，在对大厂老尾矿进行工艺矿物学研究的基础上，应用了新型高效设备，进行了小型试验及连选试验。提出了适合该矿区尾矿综合回收有价元素的高效、经济的工艺流程。取得以下成果：（1）预选抛尾技术：利用跳汰、离子型螺旋溜槽进行分级预选抛尾，可抛弃产率49．57％的尾矿，大大减轻了矿泥和碳质物的有害影响，降低了能耗和不必要的磨碎，提高入选品位，铅、锑、锌、锡、硫、砷品位分别由0．22％、0．15％、3．27％、0．57％、5．70％和0．87％提高到0．33％、0．237％、4．971％、0．878％、8．944％和1．474％。（2）铅锑的分选技术：预选抛尾后，大厂尾矿中的铅锑入选品位提高到含Pb0．33％，Sb0．237％。用ZnSO₄、NaCN和Na₂S₂O₃为组合抑制剂，用HN-1和YC-1作组合捕收剂，一次浮选富集得到含Pb7．47％、Sb4．96％的铅锑粗精矿；在用浮选进行精选很难提高指标的情况下，采用新型高效重选设备“离子波形摇床”，即通过“浮-重”联合工艺成功实现了大厂尾矿中的铅锑的有效分选，该技术是实现尾矿综合回收取得成功的关键之一。（3）锌硫砷分离技术：由于硫、砷的可浮性都比较好，所以锌与硫砷间的分离及硫砷分离都是选矿难题。该项目中，要浮锌抑硫砷，选用了高效组合抑制剂CS-2+腐植酸钠选择性抑制硫砷，实现了锌与硫砷的分离；硫砷分离时，根据硫砷被氧化剂强化氧化的难易程度不同，再采用K₂Cr₂O₇强制抑制砷浮选硫，可得到品位为36．17％，回收率为52．00％的合格硫精矿。但活化选砷时，选硫尾矿中残留的部分硫也会随着砷被活化进入砷的浮选精矿中，这样再用浮选法精选砷，难度很大。利用矿物间的密度差异，本研究采用“离子波形摇床”进行精选，即采用“浮-重”联合工艺，可获得品位为35．32％，回收率为55．97％砷精矿。（4）微细粒矿回收技术：该项目的研究过程中，采用了我们自行研制的特别适合细粒级矿物分选的新型设备---离子波型摇床。该设备床面上刷了我们研制的专用涂料，是在重力、磁力、电力、机械力诸多力作用的复合力场作用下利用矿物的电性、磁力及比重的不同进行流膜选矿，分选效果优于普通摇床，特别是细粒、微细粒的分选效果更佳，在“浮-重”联合流程中，铅锑粗精矿、砷粗精矿的精选、浮选最终尾矿选锡，都属于细粒、微细粒的重选，采用离子波型摇床均取得了很好的分选效果。（5）ZnSO₄+NaCN+Na₂S₂O₃是铁闪锌矿的优良组合抑制剂。组合抑制剂ZnSO₄+NaCN+Na₂S₂O₃的作用机理主要是在矿物表面形成亲水性膜或胶粒和溶解矿物表面捕收剂疏水膜等作用同时发生，相互补充达到强化抑制的效果。（6）YC-1的捕收能力大于HN-1，而HN-1的选择性优于YC-1，YC-1+HN-1是脆硫锑铅矿的良好捕收剂。二者组合使用的机理应为产生共吸附，增加捕收剂在矿物表面的吸附层密度。矿物表面的不同区域具有不同的活性，活性不同的HN-1和YC-1进行组合使用时，其中活性小的HN-1可吸附在活性大的矿物表面区，而活性比较小的矿物表面，适于活性大的YC-1固着，其结果为捕收剂的吸附量增加，使矿物表面吸附的药剂更加均匀。红外光谱显示，组合捕收剂HN-1+YC-1在脆硫锑铅矿表面的主要吸附产物是Pb（DTC）₂、Pb（DTP）₂、（DTC）₂和（DTP）₂。其中，Pb（DTC）₂和Pb（DTP）₂为金属四元环螯合物。生成的螯合物稳定且疏水性强，化学吸附在矿物表面，引起矿物的可浮性提高。（DTC）₂和（DTP）₂均为吸附过程中产生的捕收剂复分子，具有良好的疏水性，以分子间作用力物理吸附在矿物表面造成矿物疏水。（7）氧化剂CS-2、腐植酸钠可作为黄铁矿和毒砂的良好抑制剂，二者在不同组合形式下，可以实现选择性抑制黄铁矿和毒砂的目的。从浮选试验结果、吸附量及电位测定可以看出，CS-2存在下，ξ电位对于带电负性的黄药捕收剂并不起重要作用，硫化矿受抑制，其主要原因并不是由于CS-2与黄药产生竞争而使黄药在矿物表面吸附量减少，而可能是矿物表面因氧化形成了亲水性的氧化膜。腐钠可络合排除黄铁矿和毒砂表面的活性离子，不仅降低捕收剂的吸附，还可掩盖已吸附捕收剂的疏水性，达到抑制矿物的目的。从黄铁矿和毒砂的红外光谱知，经CS-2和腐钠作用后，二者表面均产生氧化物，但所得氧化产物有所不同。且毒砂被氧化的程度远比黄铁矿深。毒砂表面主要以FeAsO₄为主；而黄铁矿更接近于FeS₂O₃，随着氧化反应的进行，黄铁矿可被继续氧化生成FeSO₄。整个研究中，不仅采用了离子波形摇床新设备，还提出了预选抛尾工艺、“浮-重”结合选别铅锑、浮锌抑硫砷、“浮-重”结合除砷工艺、离子波形摇床回收锡石等新工艺，成功实现了对大厂老尾矿中有价矿物的回收。浮选过程中，通过研究不同的浮选药剂对矿物可浮性影响及作用机理，合理组合并使用浮选药剂，有效解决了目的矿物浮选难、指标低的问题，是该项目取得成功的关键。另外，本研究的降砷工艺，通过降低尾矿中的砷含量使之满足后续利用“二次”尾矿制造水泥的要求。更多还原

【Abstract】 The research was derived from the nation’s "tenth five" science and technology tackling key subject----the key industrial technologies’ research on development and utilization of copper, lead, zinc, tin from tailings （2003 BA612A-18）, the aim of the special subject is to recover valued components comprehensively in tailings.Cassiterite-polymetallic sulfide ores of Dachang in Guang Xi, including zinc, sulfur arsenic, lead and antimony, are typical complex refractory sulfide ores. At present, the tailings produced from polymetallic sulfide ores have accumulated about 30 million tons, containing rich tin, lead, zinc, antimony and sulfur, arsenic. Because of the limit of technical level and the condition of production, technical index of recycling metals was lower. A lot of metals, especially fine metals, lossed seriously in tailings. There were many useful minerals not being recovered. The loss of these tailings caused both a waste of resources and the hidden danger of polluting external environment of mines in Dachang. With increasing depleted resources and the ongoing large-scale production in Dachang, when the exploitation of the original ores was carried on, the secondary development and utilization of tailings and comprehensive recovery of a variety of valuable elements can generate very substantial economic and social benefits, be of great significance and value.This study aiming at recycling minerals comprehensively from polymetallic sulfide ores’ tailings, a detailed study was made about the flotation performance of jamesonite, iron sphalerite, arsenopyrite and pyrite. Through adsorption determination,ξpotential of mineral and spectra analysis for testing the surface composition, the flotation separation mechanisms of four minerals were explored. On the basis of mineralogy study in the old tailings, a new type of efficient equipment was applied, a small-scale pilot test and continuous separation test were made. Efficient and economic process suitable for the comprehensive recovery of valuable elements in the tailings was proposed and the following results were achieved:（1） Pre-throwing tailings’ technology: Using jig and ionic spiral chute in Pre-throwing tailings, 49.57% of the tailings can discarded, it greatly reduced the harmful effects of the sludge and carbon quality, while reduced energy consumption and unnecessary grinding. At the same time, it enhanced selected grade. The grade of lead, antimony, zinc, tin, sulfur and arsenic increased from 0.22%, 0.15%, 3.27%, 0.57%, 5.70% to 0.87%, 0.33%, 0.237%, 4.971%, 0.878%, 8.944% and 1.474%.（2） Separation technology of lead and antimony: After pre-throwing tailings, ZnSO₄, NaCN and Na₂S₂O₃ were used as combined inhibitors, HN-1 and YC-1 were used as combined collector. The lead-antimony crude concentrate of Pb7.47% and Sb4.96% by flotation can be enriched. But it was very difficult to raise the index by flotation further, so the new efficient equipment "Ion Waveform shaker" was used. That is, through the "flotation-weight" joint, the effective separation of lead-antimony minerals in Dachang’s tailings was realized successfully. This technology is the key of success in comprehensive recovery from tailings.（3） separation technology between zinc, sulfur and arsenic: As sulfur, arsenic can be floated better, the separation between zinc, arsenic and sulfur was mineral processing problems. In the project, it is necessary to depress sulfur and arsenic in order to float zinc. To depress sulfur and arsenic selectively, using combined inhibitors CS-2 and sodium humate efficiently can realize separation of zinc with sulfur and arsenic, and separation of sulfur and arsenic. According to the difference of oxidation degrees between sulfur and arsenic, it can strengthen further inhibition on arsenic by K₂Cr₂O₇ to float sulfur. Qualified sulphur concentrate was attained with the grade of 36.17% and the recovery of 52.00%. However, when activing and electing arsenic, residual sulphur in the tailings will be activated with arsenic into the flotation concentrate. Thus it was very difficult to separate arsenic by flotation still. According to the specific gravity difference in minerals, "Ion waveform shaker " was used to cleaning arsenic in this study. That the combined technology of flotation and gravity separation was attained arsenic concentrate with grade of 35.32% and recovery of 55.97%.（4） Fine-grained mineral recovery technology: During the study course of the project, we used a self-developed particularly suitable for separation of fine-grained minerals equipment - a new type of Ion waveform shaker. The surface of the equipment had been brushed a special coating that we developed. The flow film processing occurred, according to different electric, magnetic and weight of minerals under the composite field of gravity, magnetic, electrical, mechanical force and so on. Separation results were better than ordinary shaker, particularly fine-grained, micro-fine particles. In flotation and gravity separation process, the cleaning of rough concentrate of lead and antimony, the cleaning of arsenic rough concentrate and the election of tin from the ultimate flotation tailings all belonged to fine, fine-grained particles’ re-election. Good separation effects were achieved by ion-wave shaker.（5） ZnSO₄+NaCN+Na₂S₂O₃ were the fine combined depressants of marmatite. The mechanism of combined depressants, ZnSO₄+NaCN+Na₂S₂O₃,was mainly the formation of hydrophilic membrane or particles on mineral surface and dissolution of hydrophobic collector’s membrane on minerals surface, these functions complemented each other to enhance the inhibitory effect.（6）The collecting capacity of YC-1 was greater than HN-1 , and the selectivity of HN-1 was superior to YC-1. YC-1 + HN-1 were the good collectors of jamesonite. The mechanism of combined collectors was coadsorption, increasing density of collector’s adsorption layer on mineral surface. The surface of the minerals in different regions had different activity. When combining and using HN-1 with YC-1, HN-1 with small activity can adsorb on the high active surface of minerals, however the mineral surface with low activity was relatively suitable for fixation of YC-1 with high activity. The results were the collector’s adsorption capacity increased. The Pharmacies adsorbed on mineral surface were more homogeneously distributed. IR spectra showed that the main adsorption products of combination collectors HN-1 + YC-1 on jamesonite surface were: Pb（DTC）₂, Pb（DTP）₂, （DTC）₂ and （DTP）₂. Pb（DTC）₂ and Pb（DTP）₂ were Four-ring metal chelates. The chelates were stable and highly hydrophobic, they can adsorb on the surface of minerals by chemical adsorption and can improve minerals floating. （DTC）₂ and （DTP）₂ are collector’s bimolecular generated in the process of adsorption, they had good drainage too, and they can adsorb on the surface of minerals with physical adsorption by intermolecular force so that causing mineral hydrophobic.（7）oxidant CS-2 and sodium humate can be as good depressors of arsenopyrite and pyrite, they can achieve selective inhibition of pyrite and arsenopyrite in different combinations and dosage forms. As the flotation test results and the adsorption capacity of potential as can be seen, CS-2 can oxide pyrite and arsenopyrite, so that they have a hydrophilic surface of the oxide film. Sodium Humate can complex and eliminate active ions on the surface of arsenopyrite and pyrite. It not only reduced the collector adsorption, but also covered the hydrophobic collector absorbed, thus it attained the purpose of depressing mineral. With the presence of inhibitors,ξpotential did not play an important role for the xanthate collector charged negative. The main reason that sulphide ore was depressed was not competition between oxidants and xanthate, was rather not xanthate’s adsorption capacity reduction on the mineral surface. That may be due to oxidation on surface and the formation of a hydrophilic oxide film. From the infrared spectra of pyrite and arsenopyrite we know, when CS-2 and sodium humate existed, there were oxides both on the two mines’ surface. But the oxidation products were different. The oxidation degree of arsenopyrite was more deep than pyrite. The oxidation product on arsenopyrite surface was mainly FeAsO₄ and that of pyrite was mainly more closer FeS₂O₃.With the oxidation reaction, pyrite can be oxided and generated to FeSO₄ further.During the whole study, not only the new equipment ion-wave shaker was used but also pre-throwing tailings technology was raised. flotation and gravity separation combined technology separating lead and antimony, technology of depressing sulfur and arsenic to float zinc, gravity separation combined technology to exclude arsenic and recovering cassiterite by Ion Waveform shaker were raised and got successful recovery of the valuable minerals from the old tailings in Dachang. By studying the impact and mechanism of different flotation reagents for minerals, rational combination and use of flotation pharmacy can be as an effective solution method to solute the problem of mineral that is difficult to float and be low index. This was the key to get success in the project. In addition, the technology study of lowing down arsenic could reduce the quantity of arsenic in tailings so as to meet requirements of the following use for manufacturing cement.更多还原