As an important strategic metal, tungsten is highly valued for its wide application in high-temperature alloys, electronic devices, lighting and military industries. China has abundant tungsten resources, but with years of mining, high-quality tungsten ore resources have gradually decreased, and the utilization of low-grade and complex tungsten ores has become the key to the development of the industry.
A low-grade mixed tungsten ore contains 0.15% WO3 (tungsten trioxide). The ratio of scheelite to wolframite in the original ore is about 1:1, the mineral embedding particle size is fine, there are more than 40 types of minerals, and impurity minerals have a huge impact on tungsten beneficiation. Through detailed process mineralogy research and beneficiation tests, a process flow of "desulfurization-tungsten mixed flotation-shaking table concentration" was explored. The innovative beneficiation technology and process optimization provide new ideas for tungsten ore development.
The process of "desulfurization-tungsten mixed flotation-shaking table selection" is adopted to realize the comprehensive recovery of tungsten resources. The specific process is as follows:
(1)Desulfurization
In order to remove sulfides in the ore and reduce the impact of sulfide ore on subsequent tungsten flotation. Copper sulfate is used as an activator and butyl xanthate is used as a collector for desulfurization. The final desulfurization rate reaches 95.18%, and the tungsten loss is only 5.15%.
(2)Tungsten mixed flotation
In order to achieve the simultaneous flotation recovery of scheelite and wolframite. Lead nitrate is used as an activator and high-efficiency hydroxamic acid collector GY109 is used as a collector during flotation. Finally, a tungsten flotation concentrate with a WO3 grade of 11.55% and a recovery rate of 85.47% was obtained.
(3)Shaking table selection
In order to further enrich the tungsten flotation concentrate and improve the grade of tungsten. Use a shaking table to select the tungsten flotation concentrate.
Results: A WO3 concentrate with a grade of 50.24% and a recovery rate of 55.87% was obtained, as well as a shaker middling with a grade of 11.43% and a recovery rate of 9.14%, and a shaker tailing with a grade of 3.73% and a recovery rate of 20.46%.
(4)Treatment of tungsten flotation concentrate
Shaking table concentrate: high grade, can be sold directly as a product.
Shaking table middling: relatively coarse particle size, can be returned to the shaking table operation for further selection.
Shaking table tailing: relatively low grade, can be returned as a rich middling to the tungsten flotation coarse concentrate for selection.
(5)Optimization of the grinding process
Sodium carbonate is added in advance during the grinding process to adjust the pulp to reduce the impact of the sulfide ore oxidation process on the pulp environment, improve the flotation activity of tungsten minerals, and thus increase the flotation recovery rate of tungsten.
(6)Optimization of reagent system
By adjusting the dosage of lead nitrate and hydroxamic acid collector GY109, the collection effect of tungsten minerals is optimized and the flotation efficiency of tungsten is improved.
The design of the entire mineral processing process takes into account the characteristics of the original ore, including the ratio of scheelite to wolframite, the particle size of mineral embedding, and the interference of impurity minerals. Through this process, the effective recovery and comprehensive utilization of tungsten resources in low-grade mixed tungsten ores are achieved.
Tungsten mixed flotation obtained tungsten flotation concentrate with a WO3 grade of 11.55% and a recovery rate of 85.47%.
Shaking table concentration obtained a shaking table concentrate with a WO3 grade of 50.24% and a recovery rate of 55.87%, as well as a shaking table middling with a grade of 11.43% and a recovery rate of 9.14%, and a shaking table tailing with a grade of 3.73% and a recovery rate of 20.46%.
This low-grade tungsten ore project has achieved comprehensive recovery of tungsten resources from low-grade mixed tungsten ore through the "desulfurization-tungsten mixed flotation-shaking table concentration" process. The grade and recovery rate of tungsten flotation concentrate have reached a high level. The shaking table middling and tailings contain a high content of WO3, which can be returned for further sorting to ensure maximum tungsten utilization.
