Central South University successfully developed high-molybdenum low-grade scheelite alkaline extraction high-efficiency clean metallurgy technology

Recently, the China Nonferrous Metal Industry Association in Beijing organized a special achievement will be assessed, headed by the academician Qiu Fan given the results of the evaluation of the expert group, Central South University and Luo Yang Luan River Molybdenum Co., Ltd. (referred to as "Luo Molybdenum Group") The “High-molybdenum low-grade scheelite alkaline extraction high-efficiency clean metallurgy process and engineering demonstration” project completed by the cooperation was evaluated. The experts at the meeting agreed that the project has strong technological innovation, high comprehensive utilization of resources, low emissions of three wastes, high technology maturity, advanced technical and economic indicators, and significant economic and social benefits. It has reached international level in high molybdenum low grade scheelite treatment technology. Leading level.

Professor Zhang Guiqing from the Metallurgical Separation Science and Engineering Laboratory of the School of Metallurgy and Environment of our school cooperated with Luomo Group to provide large reserves of white tungsten in Luomo Group, low tungsten grade (WO3<30%) and symbiotic molybdenum (Mo2~3%). With the high content of phosphorus (P2O5>20%), high extraction cost of existing tungsten metallurgy technology, large wastewater discharge and low comprehensive utilization rate of resources, the first closed circuit of “sodal high pressure leaching-alkaline extraction-tungsten-molybdenum separation” was developed. Circulating process, efficient extraction of tungsten and molybdenum from low-grade scheelite to produce ammonium paratungstate (APT) and ammonium molybdate, achieving closed loop of water, alkali and ammonia, efficient and low-cost separation of tungsten and molybdenum, and tungsten and symbiotic elemental molybdenum The high value of phosphorus is comprehensively utilized. Tungsten is produced in the national standard zero-grade APT product, more than 80% of the molybdenum is produced in the form of high-value national standard zero-grade ammonium molybdate (the traditional method is low-value molybdenum slag), and phosphorus is enriched in the saleable phosphate rock. Leaching in the slag. The new process basically achieves zero discharge of waste slag and waste water. The wastewater produced by ton APT is less than 5m3, which is 80~95% lower than that of traditional method, the yield of tungsten is increased by more than 3%, and the economic benefit of ton APT is more than 9,000 yuan. Based on this technology, the first phase of the high-molybdenum low-grade scheelite comprehensive utilization demonstration project with an annual output of 10,000 tons of APT (annual output of 5,000 tons of APT) was completed and put into operation in March 2016. In October of that year, the production line was fully stable and up to standard. Production, successfully achieved large-scale industrial applications of new processes.

In addition to the industrial application of Luolu Molybdenum Tungsten Co., Ltd., the complete core technology developed by the project includes three core key technologies: “Quaternary ammonium salt alkaline tungsten extraction technology” and “Special resin continuous ion exchange deep molybdenum removal technology”. And "co-extraction depth removal tungsten technology", also as an independent unit technology in the domestic 11 other tungsten and molybdenum smelting enterprises have been promoted and applied, economic and social benefits are significant.

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