Superalloy is the key material for manufacturing hot end parts of aerospace engine, which is mainly composed of nickel, chromium, cobalt, molybdenum, aluminum, titanium, tantalum, niobium, tungsten, ruthenium, zirconium, hafnium, platinum and iridium. It is also the core material for large power equipment, such as industrial gas turbine and high-temperature gas-cooled nuclear reactor. High temperature alloy scrap containing tungsten, tantalum and hafnium mainly comes from :(1) riser, chip and car chip generated in the preparation of high temperature alloy; (2) waste from casting and forging of high-temperature alloy components and parts; (3) high-temperature alloy components and parts reaching the service life. With the rapid development of China's aerospace, aviation, gas turbine, atomic energy and other fields, the demand for superalloy is increasing, and the waste generated is also very large, which is in urgent need of comprehensive utilization of recycling. The utilization rate of superalloy in foreign countries is more than 70%, and most of the wastes in China are stored or degraded, resulting in huge waste of resources and economic losses.
The process of treating superalloy waste is wet process. Wet process is the high temperature alloy waste acid leaching and alkali leaching after pretreatment, make a recycling valuable metals in the form of ions into the solution, and using chemical precipitation, electrolytic deposition, organic solvent extraction, the displacement method, ion exchange method in the separation of one or more of the following ways to isolate rare metal elements of chemical method.
The concentration from the high temperature alloy waste tungsten, tantalum, hafnium research rarely, almost all reported enrichment recycling method is "atomized powder - leaching technology", this method is atomized powder high requirements for equipment, high energy consumption, high cost, and the activity of alloy powder is greatly increased after milling, cause in the leaching tungsten, tantalum, hafnium dispersed disadvantages such as easily. Therefore, the key to recover tungsten, tantalum and hafnium from high-temperature alloy scrap is how to make the tungsten, tantalum and hafnium in the high-temperature alloy scrap be enriched and not dispersed effectively, and separate them from other metals such as nickel, cobalt, chromium and aluminum.
