铜锌硫化矿浮选中的流体包裹体效应及调控机制

Cu-Zn sulphide mainly originates from skarn deposit, hydrothermal deposit and hydrothermal filling metasomatic type deposit, and these deposits have a large number of fluid inclusions. The fluid inclusions have abundant heavy metal components, such as copper, lead and zinc, etc. During the process of grinding, the release of fluid inclusions components and its interaction-adsorption on the mineral surface may be a new important inherent factor resulting in the difficulty in the separation of Cu-Zn sulphides from some ore deposits. Therefore, the Cu-Zn sulphide and its closely intergrown gangue minerals from a typical deposit were chosen as the research objects in present study. The infrared microscopic imaging and SEM-EDS were employed for investigating the petrography of fluid inclusions. Using a unique technique of fast impact ball mill including ultrasonic washing-centrifugalization and inductively coupled plasma source mass spectrometer (ICP-MS), the components of group fluid inclusions together with their concentration were extracted and analyzed. The concentration of the component of the heavy metals released from inclusions and their adsorption and migration on various mineral surfaces were highly concerned. Furthermore, the existence of “fluid inclusion effect” together with its effect on the flotation separation of Cu-Zn sulfides was confirmed and assessed in this study. At last, the released components in pulp were effective controlled by using a modified chitosan（DTC-CTS）, and the interaction of mineral surface with heavy metals component and DTC-CTS was investigated by density functional theory (DFT) calculation. Through this DFT calculation, it reveals the micro-mechanism of the inclusion component influence on Cu-Zn separation and also its control mechanism.

铜锌硫化矿多产于矽卡岩型、热液型、热液充填交代型的矿床中，而这类型矿床属于富含流体包裹体的矿床，这些包裹体中含有丰富的铜、铅、锌等重金属组分。磨矿过程中，矿物包裹体组分的释放和表面交互吸附，可能是导致某些铜锌硫化矿浮选分离困难的一个重要内在新致因。为此，本研究以典型矿床中的铜锌硫化矿及其脉石矿物为研究对象，采用红外显微成像和SEM-EDS分析对包裹体的岩相学进行研究；采用快速冲击球磨-超声洗涤离心分离技术和电感耦合等离子体质谱仪（ICP-MS）对群体包裹体组分进行提取与浓度分析。重点考察包裹体释放的重金属组分的含量及其在矿物表面交互吸附迁移行为，证实铜锌硫化矿浮选中存在流体包裹体效应并对其影响进行评估。最后，采用改性壳聚糖（DTC-CTS）对包裹体组分进行多元协同调控，并通过DFT计算对矿物表面与重金属组分及DTC-CTS作用进行研究，揭示包裹体组分影响铜锌分离及其调控的微观机制。

铜锌硫化矿是重要的有色金属矿产资源，在国民经济中具有重要作用和地位。铜锌浮选分离是矿物加工领域公认的难题。浮选矿浆溶液中大量存在的难免重金属组分对硫化锌矿物的天然活化是导致铜锌分离困难的一个重因素。目前，关于这些重金属组分的来源，普遍认为来源于矿物表面氧化溶解、磨矿介质、浮选用水等。然而，深入的基因矿物学研究表明，这些重金属组分还可能来源于矿物流体包裹体组分的释放，铜锌硫化矿浮选中的流体包裹体效应可能是导致其浮选分离困难的一个重要内在新致因。.为此，本项目以典型矿床中的铜锌硫化矿及其脉石矿物为研究对象，对铜锌硫化矿中流体包裹体的岩相学、包裹体的组分液的提取与浓度、包裹体组分在矿物表面交互吸附和浮选影响、铜锌分离浮选中流体包裹体组分的调控方法及作用机制等问题开展了深入研究，取得重要结果：1）铜锌硫化矿和共伴生脉石矿物中含有丰富的气液两相包裹体，铜锌硫化矿释放的金属离子量为Ca2+> Mg2+> Zn2+> Cu2+> Pb2+,其中对浮选具有活化效应的Cu2+的释放量在10-6～10-7mol/L的数量级，Cl-和SO42-的量较为稳定，在10-6mol/L～10-4mol/L；自然pH条件下，硫化矿流体包裹体组分释放对矿浆溶液中重金属离子来源占优势地位；2）矿物对包裹体组分液中的Cu、Pb、Zn重金属组分具有较强的吸附活性，自然pH和碱性条件下矿物对铜组分的吸附量大小为：闪锌矿≈石英+方解石＞＞黄铜矿，包裹体组分的表面吸附致使铜锌浮选分离困难；3）提出了 “矿浆溶液化学调控和矿物表面亲水性/活化位点调控”相结合的裹体组分调控方法，研发了绿色高分子有机药剂改性壳聚糖和小分子有机螯合药剂二甲基二硫代氨基甲酸钠复配药剂，可以对流体包裹体活化组分进行有效调控，实现了铜锌高效分离、铜精矿中含锌仅4%左右；4）改性壳聚糖实现铜锌分离的机制一是占据矿物表面活化位点并使之亲水，二是阻碍后续闪锌矿表面捕收剂的吸附。.本项目对揭示金属硫化矿浮选分离困难的内在新致因具有重要的科学意义，对复杂多金属硫化矿的浮选分离具有指导作用。