Hydrometallic Alkali Decomposition Technology for Scheelite Smelting

Tungsten in scheelite often fuses with molybdenum, copper, and other elements, making separation difficult. Molybdenum, in particular, shares similar chemical properties with tungsten, leading to even more problems and challenges in separation.

Wet alkaline decomposition technology in scheelite smelting can be analyzed from two main aspects: sodium hydroxide leaching and sodium carbonate pressure cooking. Sodium hydroxide leaching is more suitable for smelting mixed concentrates of scheelite and wolframite. Under suitable temperature conditions, sodium hydroxide solution is introduced to react with the tungsten ore, producing sodium tungstate to complete the smelting process. Sodium carbonate pressure cooking, on the other hand, is more commonly used in scheelite smelting. This technology requires relatively high temperature and pressure control in practice. It necessitates precise temperature and pressure control to allow sodium carbonate to react with the scheelite and produce soluble sodium tungstate. The key considerations for this technology in practical application include the following:

In the process of implementing scheelite smelting, relevant personnel need to strengthen the control of alkali concentration and liquid-solid ratio to better ensure the reaction effect. Secondly, in the application of wet alkaline decomposition technology, temperature and pressure parameters require special attention and control. These parameters need to be adjusted appropriately based on the specific technical application requirements, key points, and the volume of scheelite to be processed. Thirdly, equipment corrosion may occur during scheelite smelting, affecting equipment lifespan and increasing operating costs and pressure for related enterprises. To better avoid such problems, multi-stage countercurrent leaching can be used to increase the tungsten leaching rate. Furthermore, introducing titanium materials or titanium-lined equipment can reduce corrosion and its impact on the equipment.

Wet alkaline decomposition technology consumes relatively little energy in practical applications, and the cost is relatively low in processing low-grade ores, showing significant advantages. However, its limitations are also quite apparent. First, the practical application of this technology involves high-voltage equipment, requiring relatively significant resource investment in equipment purchase, operation, and maintenance. Second, wet alkaline decomposition technology easily generates alkaline wastewater with relatively high alkali concentrations, making treatment difficult and potentially causing environmental pollution. Finally, the process flow involved in wet alkaline decomposition technology is relatively complex, requiring the configuration of solution purification and evaporation crystallization systems to better ensure its application benefits.