With only 23 years of mining guarantees remaining, it supplies 80% of global tungsten demand and lacks the right to speak in international competition... This is the status quo of China's dominant mineral resources, metal tungsten. For a long time, China's tungsten resources ranked first in the world due to reserves, production and exports, and were called “three firsts†by people in the industry. However, after years of exploitation, China has faced a serious tungsten resource crisis, not only in quantity but also in quality. Recently, at the 430th Xiangshan Science Conference Symposium on the topic of “Efficient Extraction and Recycling of Rare Earth Resources Based on Tungstenâ€, Qiu Xianyang, Executive Chairman of the Conference and Dean of Guangzhou Nonferrous Metals Research Institute, pointed out: “How to efficiently extract and The development of tungsten resources and the application value of tungsten resources have become the top priority for China to move from a tungsten resource country to a tungsten resource power." The resource crisis highlights that Dayu County in Jiangxi Province is the earliest county in China to discover black tungsten ore. It has been hailed as "China." The birthplace of the tungsten industry, but it was listed on the list of “the third batch of resource-exhausted cities in the country†announced at the end of 2011. The change of Dayu County is a microcosm of China's tungsten resource crisis. According to statistics, from 2003 to 2011, China's tungsten ore reserves decreased from 4.2 million tons to 1.9 million tons, a decrease of 54.8%. According to the production capacity of China's tungsten resources in 2010, the current mining guarantee period for tungsten base reserves is only 23 years. What is even more worrying is that the quality of tungsten resources is also quite serious. Qiu Xianyang told the Journal of the Chinese Academy of Sciences: "With the annual exploitation of tungsten resources, the grade of tungsten mines has been decreasing year by year." Mineralogy, metal tungsten forms tungstates in the process of mineralization, of which black tungsten Mines (tungsten manganese ore) and scheelite (calcium tungstate) have the most industrial value. The composition of the black tungsten ore is relatively simple and easy to select. The scheelite has less rich ore, complex components and lower grade. For a long time, this low-grade complex tungsten raw material, although accounting for 70% of the national tungsten resource reserves, is still difficult to obtain the favor of the black tungsten mine. For this reason, most of the previous consumption in China was black tungsten ore. However, the current reality is that “the black tungsten resources are getting closer and closer, and the situation dominated by scheelite has been formed.†Sun Chuanqi, an academician of the Chinese Academy of Engineering and a researcher at the Beijing Research Institute of Mining and Metallurgy, said bluntly. Metallurgical problems need to be solved in low-grade tungsten ore, often containing impurities such as molybdenum, phosphorus, arsenic, silicon, etc., which increases the difficulty of metallurgical extraction. At present, the decomposition technology of tungsten and high content impurities is not mature. The existing extraction method, ion exchange method and precipitation method not only consume a large amount of chemical reagents, but also cause environmental pollution. The addition of excess auxiliary materials will also bring difficulties to the subsequent processes. "China's tungsten wet smelting level is the world's leading position. Industrial use of sodium hydroxide to decompose scheelite and widely promoted." Zhao Zhongwei, a professor at the School of Metallurgical Science and Engineering, Central South University, told the Journal of the Chinese Academy of Sciences: "In the past, this was Foreign countries believe that it is impossible to carry out. However, even if the amount of alkali is increased by 4 to 6 times, the separation of low-grade tungsten ore still fails to achieve good results. According to statistics, the tungsten content in China's tungsten smelting waste residue is as high as 2.5%, and the annual loss of tungsten concentrate is as high as 3,550 tons, which is equivalent to the output of a large tungsten ore. The increase in the amount of alkali will lead to a high processing cost, and the consumption of auxiliary materials and heat and kinetic energy will increase substantially. Zhao Zhongwei believes that the existing technology is mainly produced with low-grade tungsten ore as raw material, and economic metallurgy cannot be realized because the cost is too high. At the same time, the tungsten metallurgical environment is seriously polluted. The latest data shows that the annual discharge of tungsten smelting wastewater in China amounts to 16 million tons, and all the indicators of wastewater far exceed the national standards. The domestic tungsten smelting enterprises are unable to achieve zero discharge of wastewater. “The extraction process emits a high concentration of sodium sulfate wastewater, and the ion exchange process emits a large amount of low-concentration salty wastewater,†Qiu Xianyang said. The high-end products lacked the academician of the Chinese Academy of Engineering and professor of Beijing University of Technology, left Tie Teng pointed out: "Tungsten is an irreplaceable 'strategic metal' in modern defense, and its industrial products should also be the focus of the entire industry." In recent years, China's tungsten products preparation Great progress has been made, with production accounting for more than 40% of the world, ranking first in the world. However, in terms of performance, domestic tungsten products are mainly dominated by medium and low grades. “Preparation technology and equipment level of high-precision, large-size, complex tungsten products and functionally graded alloys are quite different from those in foreign countries. The properties such as product density, hardness and fracture toughness cannot meet the requirements of modern industrial and defense industries for tungsten products. "Qiu Xianyang said. Cemented carbide products are a major tungsten product. At present, there are more than 600 cemented carbide enterprises in China, and the proportion of high value-added products such as high-precision cutting tools, molds and engineering machinery parts is extremely low. This is because the purity, particle size and uniformity control of domestic tungsten products have not been effectively solved, and the construction of technical quality standards of enterprises has lagged behind. According to the survey, most enterprises have less investment in science and technology, and R&D investment is less than 1% of sales revenue, which directly affects the breakthrough of original high-end products. At the same time, the tungsten content of waste cemented carbide is about 40% to 95%, and the utilization rate of waste cemented carbide in the United States has accounted for 35% to 40% of its total tungsten content. It is estimated that the utilization rate of secondary tungsten resources in China is only about 24%. Increasing the secondary resource recovery rate of tungsten products is expected to achieve sustainable development of tungsten resources, energy and the environment. In this regard, Qiu Xianyang pointed out that the dissociation of tungsten and the purification and conversion of tungsten compounds are the key technologies to be broken in this process. In addition, the participating experts agreed that the active development of mine recycling clean production technology, the separation of tungsten minerals and associated elements and the material properties of a new generation of tungsten-based alloys can solve the current mining, smelting and manufacturing of low-grade tungsten resources. The problem is to achieve green and efficient development of tungsten resources, thus promoting the rise of the entire tungsten industry.
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