Roasting process of sulfuric acid of rare-earth ore

The invention discloses a roasting process of sulfuric acid of rare-earth ore, comprising the steps of using rare-earth raw ore and rare-earth concentrate as raw materials, adding sulfuric acid according to acid-to-concentrate ratio, evenly mixing, roasting the rare-earth raw ore and rare-earth concentrate added with acid in a high-temperature chamber furnace, adding water into roasted ore at room temperature, then leaching and filtering to obtain once-leaching solution and once-leaching slag filter cake; using industrial magnesia to neutralize the once-leaching solution, adding water into the once-leaching slag filter cake for twice leaching, filtering the neutralized once-leaching solution to obtain neutralized solution and neutralized slag filter cake, carrying out acid dissolving on the neutralization slag filter cake and filtering, mixing the filtered solution after entering the water leaching solution to obtain the water leaching solution product, filtering the once-leaching slag filter cake after twice