Reuse of Refractory Metals such as Tungsten, Molybdenum and Niobium

Refractory metals such as tungsten, tantalum, niobium, tantalum and molybdenum are extremely important applications in high-tech fields such as atomic energy, aerospace, electronic information and medical diagnosis and treatment involving national security and national economy. Represented by tungsten, China has outstanding resource advantages in this metal, accounting for more than 60% of the world's total tungsten ore reserves. In the past decade, the output of tungsten-related products has accounted for 80% to 90% of the global total output. Most of the tungsten resources consumed by the world's tungsten industry come from China, causing a significant drop in the storage of such high-quality strategic resources in China. Based on this, the application of refractory metals and the utilization of secondary resources have been highly valued.

According to the Science and Technology Daily, the project team consisting of the Beijing Institute of Technology, the 718th Research Institute of China Shipbuilding Industry Corporation, the China Institute of Atomic Energy and the Kunming University of Science and Technology, is manufacturing a complete set of high-end products for refractory metals based on secondary resource utilization. And applied research has made a major breakthrough.

Tan Chengwen, a professor at the Beijing Institute of Technology, is the project leader. Through the application of basic research and industrialization, the project team has opened up the entire chain industrialization technology from recycling waste to electronic grade WF6 gas and ultra-high purity tungsten parts. WF6 high-efficiency fluorination preparation and purification, high-purity tungsten target, tungsten heating body, shaped tungsten ruthenium by atmospheric pressure chemical vapor deposition, based on tail gas utilization of high-purity ultra-fine tungsten powder plasma chemical method, by-product HF Key technologies such as F2/NF3 and H2 electrolysis and its application in the preparation and reduction of WF6.

After about 10 years of hard work, the project team developed high-purity products such as high-purity WF6, ultra-high-purity tungsten target, high-purity tungsten parts for ion implanters, high-performance tungsten heating bodies, and high-purity shaped tungsten bismuth. Among them, the purity of high-purity WF6 is 99.999%, which meets the high purity requirements of special gases in the semiconductor industry. It is widely used in domestic and foreign well-known semiconductor companies such as Intel, Toshiba, TSMC, and SMIC. The domestic market share is 80%. The market share is nearly 25%. In just 3 years, the annual output value of a single product is over 100 million yuan, and the profit rate is more than 20%. As technology continues to improve, the use of products in related companies has increased significantly, breaking foreign monopolies. Ultra-high-purity tungsten target, high-purity tungsten parts for ion implanters, tungsten heating bodies, and shaped tungsten ruthenium have a purity of 99.999999%.

Up to now, the high-purity tungsten parts used in ion implanters have been tested by end users, which is about 1/3 higher than the service life of similar products supplied by Austrian Plancy; the evaluation of high-performance tungsten heating bodies in the core components of a major project in the nuclear industry. It has been applied to ensure the reliable implementation of high-temperature long-term evaluation experiments; the application of high-purity hetero-tungsten in the crystal industry, such as the Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, will greatly improve the crystal growth quality and greatly reduce the growth of crystals. Cost; ultra-high purity tungsten target is being tested by Applied Materials, the most representative semiconductor equipment company in the world; the development of a new structure tungsten divertor module for nuclear fusion developed jointly with the Institute of Physics and Chemistry of the Chinese Academy of Sciences is progressing smoothly. Continuous funding from the Ministry of Science and Technology. It is understood that various products show excellent market prospects and will greatly enhance the international competitiveness of China's semiconductor and other high-tech fields. Related technologies are also being promoted and applied to other refractory metals other than tungsten, such as ruthenium, osmium and iridium.

Tan Chengwen said that the project uses the synthesis and decomposition reaction of WF6 to realize the full and high-end utilization of the strategic refractory metal secondary resources such as tungsten through a complete cycle process, forming a special electronic gas WF6, ultra-high purity tungsten parts and High-tech products such as high-purity tungsten powder, which are used in many fields such as semiconductor, atomic energy, aerospace, and medical diagnosis and treatment. Moreover, the whole process has no harmful emissions and is environmentally friendly, which overcomes the environmental problems in the process of secondary resource utilization in the past.