Changchun Gold Research Institute successfully solved international hardship in copper-molybdenum separation in Wushan
Wushan project short for Wunugetushan copper molybdenum project in Inner Mongolia Mining Co., Ltd., China National Gold Group Corporation, is the representative project Group Company made for the Big Base construction in the 12th five-year plan.
Wushan is the fourth largest associated copper and molybdenum deposit in China, which is a typical large scale low grade porphyrite type copper-molybdenum deposit. Due to that, effective recovery of molybdenum in the ore is the foundation to economically utilize the resources before molybdenum is separated from mixed concentrates.
As is known, copper-molybdenum separation has been an international headache while the separation complexity in Wushan is even harder. There are many problems to be solved and new production methods to be needed.
Restraints brought by copper-molybdenum separation are becoming more and more evident with the production scale of Wushan expands. Molybdenum in ores can not be made full use of if the separation problems are not properly dealt with, and this will severely deteriorate economic benefits of the enterprise and even decide whether the mine can survive or not.
Consequently, the copper-molybdenum separation is concerned with life and death issue of Wushan project.
Difficulties displayed in copper-molybdenum separation are as follows:
Firstly, copper minerals in ores mostly are secondary copper minerals of which the contents sometimes are as high as 75%. Affected by the incontrollable secondary copper minerals, copper-depressing and molybdenum flotation process is of little effect to production. During the commissioning of the project, excessive content of copper in molybdenum concentrates is the main reason why research on copper-molybdenum separation has not made progress.
Secondly, satisfactory copper-molybdenum separation processes overseas mainly use pure water and do not recycle it after separation. Yet Wushan mine has short water supply forcing the production to reclaim used water. The recycled water supplied by Manzhouli City is only adequate for life in the mining area and is not enough for production.
And thirdly, as copper and molybdenum do not get along, the grade of copper increases while that of molybdenum decreases, vice verse. With the mining depth deepens, the grade of copper will gradually decline. The easily separated high copper and low molybdenum content resources are becoming scarce. But because of the high molybdenum and low copper content resources can not avoid being mined and the problems of copper-molybdenum separation are not totally resolved, the resources have to be transported outside the mining area and stacked up, bringing unspeakable difficulty to the production.
Aiming at the solution of the hard situation, Changchun Gold Research Institute is commissioned by the Group Company to undertake the copper-molybdenum separation project. Changchun Gold Research Institute collected samples in Wushan mine and organized four research teams including one process mineralogical team, two process development teams and one flotation water recycling team.
Up till September in 2011, each team pleasingly had completed indoor work and reached a definite process design and technical route.
In November, 2011, a research team directed by vice dean of Changchun Gold Research Institute was assigned to field working in Wushan. Integrated into the in-situ conditions, the team took part in the commissioning, draw out plans and further optimization program of the process with the staff on field.
During the period from October to December, 2012, copper-molybdenum separation in Wushan was conducted exactly as the institute proposed and it took only 41 days to complete the optimization, 4 days ahead of the previous plan.
Commissioning was commenced on December 6 and proved to be successful. On December 9, molybdenum concentrates in good quality were produced and a stable grade of 50% was achieved.
Through optimization made after December 31, the average recovery rate reaches 82%. The rate mostly ranges from 80%—88%, with the highest of 94.50%.
When the copper-molybdenum separation production project is completed, Wushan mine can save about 150 million yuan annually.