The invention provides a method for 
smelting and separating 
uranium, 
thorium and 
rare earth from residual 
slag of processed 
monazite. The residual 
slag of processed 
monazite is used as the 
raw material. The method comprises the following steps of performing 
hydrochloric acid complete dissolving, performing dissolving liquid aging, performing liquid-
solid separation, extracting 
uranium by an amineextraction agent and performing extracting and enriching, extracting 
thorium from an acidic 
phosphorus-containing extraction agent and performing 
wastewater treatment. A 
raffinate phase obtained afterthorium extraction is returned to a 
monazite hydrochloric acid optimum solubilizing procedure to recover a 
rare earth chloride mixture, after extraction and separation, a single 
uranium product and athorium product are obtained through 
precipitation, and the 
recovery rate of resources such as uranium, 
thorium and 
rare earth is greater than 95%; and most of process water in the production processis directly returned to a 
system for cyclic utilization, a small amount of 
wastewater is recycled back to the 
system after comprehensive treatment, and zero drainage of the 
wastewater is realized. Bythe adoption of the technical scheme, the flow is simple and flexible, and large-scale production is achieved easily; the chemical 
material consumption is low, valuable resources such as rare earth,uranium and thorium can be efficiently recovered, and the 
resource recovery rate is increased; and the comprehensive treatment and environmental-friendly, efficient and clean production of the monazite resources are guaranteed.