选冶联合回收石煤中伴生战略金属钒镍钼的研究进展

Research Progress on Recovery of Associated Strategic Metals Vanadium,Nickel and Molybdenum from Stone Coal by Combined Process of Beneficiation and Metallurgy

针对石煤中钒镍钼综合利用率低,战略金属镍、钼优质矿产资源匮乏的问题,综述了石煤中钒、镍、钼的赋存状态及选冶联合回收研究现状,归纳总结了碳质石煤、钙质石煤、碳质钙质石煤、硅质石煤等不同特点石煤的选冶联合提钒工艺,讨论了不同特点石煤采用的焙烧、浮选、浸出、脱泥、磁选、重选等联合提钒方法,介绍了从部分石煤中富集有回收价值镍、钼的焙烧-浸出及浮选-浸出方法。指出了当前的回收工艺还存在石煤中镍、钼的工艺矿物学研究不够完善、含钒矿物与脉石分离困难、浮选回收钒云母品位低等问题。展望了后续应重视石煤中微细粒矿物分散絮凝行为研究,设计高效的脱泥和脱碳设备,研制新型的钒、镍、钼浮选药剂及浸出剂,优化选冶联合工艺流程,以降低生产成本、绿色低碳发展为标准,最终实现选冶流程在石煤工业上的广泛应用。

Nickel,molybdenum and vanadium are important strategic metal resources in China,which are widely used in metallurgy,electronics,steel,aerospace and other industries.With the large consumption of high-quality nickel molybdenum vanadium resources,the development of traditional vanadium nickel molybdenum resources is more and more difficult,how to use non-traditional nickel molybdenum vanadium resources has become an urgent problem.In view of the lack of high-quality mineral resources of strategic metals such as vanadium,nickel and molybdenum,and the low comprehensive utilization rate of vanadium,nickel and molybdenum in stone coal,this paper summarized the occurrence state of vanadium,nickel and molybdenum associated with stone coal and the research status of combined beneficiation and metallurgy.The combined vanadium extraction process of carbonaceous stone coal,calcareous stone coal,carbonaceous calcareous stone coal and siliceous stone coal was summarized.For carbonaceous stone coal,it was necessary to remove carbon by roasting or flotation,and then extract vanadium by flotation-leaching,in order to reduce the influence of carbonaceous materials in stone coal on the leaching process.Calcareous stone coal contained many calcites.Under the traditional high-temperature roasting conditions,CaO decomposed from calcite reacts with vanadium-containing oxides to form calcium vanadate,which made vanadium wrapped and affects the leaching effect.Moreover,calcite was also a acid-consuming mineral,so it was necessary to remove some calcites before enriching vanadium.The combined process of beneficiation and metallurgy of carbonaceous calcareous stone coal needed to be combined with the above two stone coal treatment methods.The process flow was roasting decarburization-reverse flotation calcite-positive flotation mica.Generally,in order to reduce the influence of slime contained in roasted ore on flotation,desliming would be carried out before flotation.In addition,shaking table separation could be used according to the physical properties of vanadium mica and gangue minerals in stone coal,and the process flow was roasting decarbonization-gravity separation.The main vanadium-bearing minerals in siliceous stone coal were mica and fine-grained clay and iron oxide minerals.The recovery of fine-grained minerals could be carried out by scrubbing desliming and screening.The process was roasting decarburization-scrubbing desliming-flotation,wet screening-mixed acid ripening.For a small part of vanadium in iron oxide magnetic minerals,magnetic separation could be used for recovery.From the above different processes,it could be seen that due to the differences in the types of stone coal in various regions,the target minerals were closely combined with gangue,which made the mineral processing and smelting processes of stone coal diverse,and there was no unified method,which was also one of the reasons why there was no large-scale industrial application.In a small number of regions,the associated nickel and molybdenum elements in stone coal had high recovery value,which could be used as mineral resources for separate mining.Due to the large differences in stone coal in different regions,stone coal with low nickel and molybdenum grade could also be enriched as by-product in the recovery of vanadium at the same time,so as to improve the utilization rate of stone coal.The process mineralogy research showed that nickel and molybdenum in stone coal mostly existed in the form of sulfide.This paper introduced the existing recovery methods of nickel and molybdenum from stone coal,including roasting-leaching and flotation-leaching.For stone coal with high nickel and molybdenum grade,the leaching rates of nickel and molybdenum by traditional roasting-leaching process were high,but there were problems such as high smelting cost.For stone coal with low grade of nickel and molybdenum,flotation-leaching process was used to improve the grade of nickel and molybdenum by pre-concentration and reduce the amount of ore treatment,but the industrial application was less.At present,there were few studies on the recovery of nickel,molybdenum and other associated elements from stone coal.The key reason was that the occurrence state of associated elements in stone coal was relatively complex,and the process mineralogy research on nickel and molybdenum was not thorough enough.Moreover,the grade of nickel and molybdenum in most mining areas was low,and the recovery value was not high.Finally,it was proposed that in order to achieve efficient separation and enrichment of vanadium,nickel and molybdenum in stone coal,the following problems still existed:(1)The process mineralogy research of nickel and molybdenum in stone coal was still imperfect.(2)It was difficult to separate valuable minerals from gangue minerals in stone coal,and the grade of vanadium mica recovered by flotation was low.It was pointed out that the development trend of the combined process of beneficiation and metallurgy were as follow:(1)To research on new desliming equipment and decarburization equipment;(2)To develop new flotation reagents,gangue inhibitors and green leaching aids;(3)To optimize the process of combined recovery of vanadium,nickel and molybdenum,and take reduce production costs,green and low carbon development as the standard,finally realize the wide application of the process in the stone coal industry.