Owing to the disadvantages of difficult recovery,and high cost for acidic leaching calcination of Th at high temperature and low recovery rate for that at low temperatures,the new process of sulfuric acid leaching of low grade rare earth concentrate by microwave heating at low temperature was studied. Temperature rise properties were firstly investigated,and the effects of roasting temperature,the rate of acid to ore,roasting time of rare earth concentrate treated with microwave heating and sulfuric acid on...