难处理钨矿物资源高效利用物理化学

The problems associate with traditional alkaline process for treating low-grade complex scheelite concentrate lies mainly in low leaching efficiency, large quantity of wastes release and difficult in comprehensive utilization. Here, a new coordinative hydrometallurgical system is put forward for efficient extraction, using H2SO4-H3PO4 mixed acid solution.. It is expected to develop the physical chemistry theory for the novel hydrometallurgical process and provide theoretical support for technical revolution of tungsten metallurgy and efficient utilization of complex resource. The main problem to be researched are: 1) the decomposition mechanism of calcium minerals contained in refractory tungsten ores and the control approach for morphology of calcium sulfate product, 2) the crystallization equilibrium of tungsten in the H2SO4-H3PO4-H2O system and the effect of Ca, Mg, Al and Fe, 3) the interaction behavior of W/Mo ion-association complex and, the mechanism of its effect on the separation of W and Mo in the acidic solution, 4) the separation and transformation behavior of component in the process of preparing ammonium paratungstate from phosphotungstic heteropoly acid and 5) the crystalline phase chemistry of Ca and other impurities in the process of H3PO4 distributary.. The advantages of acidic extraction system based on new theory are as follows: 1) suitable for complex refractory ores, moderate leaching conditions, high leaching efficiency; 2) easy separation of W & Mo since they behaves more differently in high acidity solution; 3) phosphate associated in concentrate turn to be beneficial for leach and, can be utilized comprehensively as H3PO4 byproduct; 4) recycling of waste water, no waste release; 5) gypsum is the main residue of sulfuric leaching and can be used as building materials and 6) cheap reagent.

针对品位低复杂白钨资源用传统碱法处理时存在的浸出率低、三废排放量大、综合利用难等问题，提出了硫磷混合酸协同高效提取的冶金新体系。通过研究：1）难处理钨矿中各种含钙矿物的分解机理与硫酸钙的形态形貌控制途径；2）硫酸—磷酸—水溶液体系中钨的析出平衡以及钙、镁、铝、铁等的影响规律；3）酸性条件下钨/钼缔合物离子的相互作用行为以及对钨钼的高效分离的影响机制；4）由磷钨杂多酸制备仲钨酸铵过程中的组分分离与转化行为；5）副产磷酸过程中钙等杂质的结晶相化学等问题，构筑复杂难处理白钨矿资源的冶金物理化学新理论，为钨湿法冶金技术革命和资源的高效利用提供理论支撑。预期基于新理论的酸性提取体系的优点：适合复杂难处理矿，浸出条件温和、浸出率高；伴生元素钼与钨的性质差异最大，容易分离；伴生磷可利用促进浸出，并可开路作为磷酸综合利用；浸出液循环使用，过程可望无废水；硫酸浸出渣主要为石膏，可作为建筑材料；试剂廉价。

本项目打破了传统钨碱法冶金的思路，设计了硫磷混合酸协同高效提取钨的新体系。研究了新体系下钨冶金的物理化学，具体如下：1）研究了难处理钨矿中各种含钙矿物的分解机理，提出了硫酸钙的形态形貌控制手段；2）研究了硫酸—磷酸—水溶液体系中钨的析出平衡以及钙、镁、铝、铁等的影响规律，形成了冷却结晶提取磷钨酸，母液循环浸出的新技术；3）研究了酸性溶液中钨/钼的相互作用行为以及对钨钼的高效分离的影响机制；4）研究了磷钨杂多酸晶体氨溶转化后钨磷分离机理及钨酸铵结晶的调控机制，优化了磷酸铵镁法深度净化磷的技术参数；5）研究了硫磷混酸体系中钙的脱除行为，提出了加入晶种/冷却结晶脱除钙的技术；6）研究了硫磷混酸体系中钨钼离子随溶液酸度结构演变差异性变化规律，为钨钼深度分离提供了技术思路。其成果构筑了复杂难处理白钨矿资源的冶金物理化学新理论，为钨湿法冶金技术革命和资源的高效利用提供理论支撑。新的钨冶炼体系适合复杂难处理矿，浸出条件温和、浸出率高；伴生元素钼与钨的性质差异最大，容易分离；伴生磷可利用促进浸出，并可开路作为磷酸综合利用；浸出液循环使用，无废水排放；硫酸浸出渣主要为石膏，可作为建筑材料；试剂廉价。