Recent Advances in the Utilization of Tungsten Residue: A Mini Review of China

Abstract

As a metal of strategic value, tungsten plays an important part in civil and military applications. Currently, China is the biggest tungsten producer all over the world, and the metallic smelting technologies for tungsten are well established. However, the harmless recovery and treatment procedures for tungsten residue remain rather underdeveloped. The treatment of tungsten residue generally includes the recovery of valuable metals (e.g., scandium, tantalum, and niobium) and the solidification of toxic elements (e.g., arsenic, lead, and chromium), which may control the transfer of these elements and metals. If treated improperly, the resource of tungsten residue may be wasted, and potential environmental risks could arise. Therefore, the safe disposition of tungsten residue has become the limit factor and an urgent problem to be solved for the sustainable development of tungsten-related industries. In this regard, we reviewed the industrial background of tungsten and the composition and toxicity characteristics of tungsten residue. In addition, particular attention was paid to the harmless utilization processes and technologies for tungsten residue, which were then systematically compared in terms of the applicable situations as well as their advantages and shortcomings. Finally, the development trend for the harmless utilization of tungsten residue was discussed, and some proposals for further studies were provided.

Simultaneously Recovery of Thorium and Tungsten through Hybrid Electrolysis–Nanofiltration Processes

“…Utilization of tungsten residue [1] Tungsten resources and potential extraction [3] Recovery of W(VI) from wolframite ore using new synthetic Schiff-based derivative [17] Extraction of sodium tungstate from tungsten ore [18] Progress in sustainable recycling and circular economy of tungsten carbide [19] Tungsten resources and potential extraction from mine waste [20] Thorium Recovery and transport of thorium (IV) through polymer inclusion membrane [9] Process for the separation of U(VI), Th(IV) from rare earth elements by using ionic liquid Cyphos IL 104. [11] Thorium removal, recovery, and recycling [12] Polymeric materials for rare earth element recovery [13] Highly efficient adsorbent to remove thorium ions [15] Impacts of uranium-and thorium-based fuel cycles with different recycle options [16] The interest in thorium is argued both because it is a material with huge potential for energy generation, including nuclear energy [31][32][33][34][35][36][37][38][39][40], but also because, although it is radioactive, it is the object of some domestic applications that capitalize on the resistance to high temperatures of thorium dioxide (lamps, shields, crucibles, and welding electrodes) [41] or its special refractive index (lenses, glasses, and high-resolution optoelectronic apparatus) [12].…”

“…The performances proven by membrane separation processes in various ecological and greening technologies constitute important arguments for their involvement in the recovery and recycling of various urban wastes, especially those that generate toxic products [ 1 , 2 , 3 , 4 ]. Thus, in order to develop a technology for the separation and valorization of some metallic elements from specific urban waste, baromembrane processes can be applied, when the elements are in a colloidal (nanometric) or suspension (micrometric) state, or processes with electric and/or concentration gradient, if the metals are found in the forms of ions [ 5 , 6 , 7 , 8 ].…”

“…Moreover, tungsten has been the focus of process engineers for its recovery from various residues through electrolytic processes and acid or basic solubilization processes [ 26 , 27 , 28 , 29 , 30 ]. On the other hand, thorium has been the focus of researchers in the field of membranes for concentration, separation or purification, especially when it comes from ores in which uranium or rare earths can also be found [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ] ( Table 1 ).…”