The resource utilization of tungsten alloy waste is prone to produce tungsten-containing alkaline residue,and the tungsten content in this part of tungsten-containing alkaline residue is high.In this paper,a compound salt(Na2CO3-Na2SO4)melting process was developed for the efficient separation of tungsten.The effects of the addition amount of Na2CO3 and Na2SO4,the melting temperature of the compound salt,the melting time as well as the water leaching liquid-solid ratio and the water leaching temperature on the recovery of tungsten were investigated.The results show that the optimal conditions of separating tungsten from alkali molten slag are n(W)∶n(Na2CO3)∶n(Na2SO4)=1∶1.25∶0.54,the melting temperature of the compound salt is 800℃,the melting time is 3 h,the water leaching liquid-solid ratio is 2.5,the water leaching temperature is 75℃,and 99.93%of the tungsten metal in the tungsten-bearing alkali residue can be optimally separated out.Meanwhile,the reaction mechanism of compound salt melting was discussed in this paper based on XRD analysis and thermodynamic analysis.The construction of compound salt system helps to reduce the eutectic point of the system save energy consumption,and also helps to promote the full contact between alkali-soluble slag and reaction medium to improve the reaction efficiency.
tungsten alloy scrapalkali leach residue containing tungstencompound salt meltingthermodynamics
NETL
NSTL
万方数据
