Tantalum and hafnium belong to strategic metals and are widely used in the field of national defense industry. Tantalum hafnium resource in our country, although have some reserves, limited by factors such as grade, production cost and mining technology, the annual domestic tantalum hafnium far cannot meet the demand of domestic smelting, as a strategic reserve, metal tantalum hafnium imports are vulnerable to the international situation, the high temperature alloy waste contains considerable valuable metallic elements, if these valuable metallic elements can be recycled for the use and application of strategic metals have very important significance, such as the patent CN103834815A released a including tantalum rich tungsten tantalum in tungsten slag separation method, Tantalum by sodium carbonate, sodium hydroxide and its contain rich after tungsten slag mix roasting and water immersion process to separate tungsten tantalum, separation effect is better, in addition, the conventional acid leaching processing and roasting - separation of the water treatment process of high temperature alloy scrap can be nickel, cobalt, tungsten, molybdenum and other metal recycling valuable metals, still have a certain amount of tantalum in the rest of the alloy slag and hafnium, most of these tantalum hafnium alloy slag down-cycled, caused the waste of resources and environmental pollution, if can recycle the tantalum hafnium, not only can make up for the external dependence of tantalum hafnium resource in our country, to protect China's strategic needs, And can provide more tantalum and hafnium reserves for our country. According to published reports, the separation of tantalum and hafnium from high-temperature alloy is carried out under hydrofluoric acid system. Hydrofluoric acid has strong volatility and toxicity, which has a great impact on environmental damage. In addition, China has increasingly strict requirements on industrial environmental protection.
Its characteristics lie in, including the following steps: step 1, mix sodium carbonate and tantalum hafnium alloy slag evenly to get roasting raw materials; The mass ratio of the tantalum and hafnium alloy slag and sodium carbonate is 1:(0.6 ~ 1); Step 2: the calcined raw materials mentioned in step 1 were calcined at a temperature of 1000℃ ~ 1200℃ and in an oxygen atmosphere for 1.5h ~ 3.5h to obtain the calcined products. After the calcined products were cooled, they were placed in concentrated sulfuric acid and heated to 50℃ ~ 70℃ under agitation for 1h ~ 2h to obtain the solid-liquid mixture. Step three, add deionized water to the solid-liquid mixture in step two, mix evenly and filter, get filtrate and filter residue, and achieve tantalum and hafnium separation.
