Leaching the co-precipitated thorium from light rare earth double sulfate and preparation of high-grade thorium concentrate

Abstract EN

During selective precipitation of light rare earth elements from concentrated sulfuric acid monazite sulfate leach solutions, substantial amount of thorium was co-precipitated.

the current study deals with leaching most of this co-precipitated thorium under various conditions of pH, solution / solid precipitate ratio, agitation time, and leaching temperature.

additionally, the preparation of high-grade thorium concentrate suitable for further purification steps was involved from the produced leach liquors.

this is conducted through some thorium selective precipitation methods such as precipitation at controlled pH value and hydrolysis.

the optimized conditions reveal that leach water of pH = 1.0, the ratio to light rare earth double sulfate solid precipitate is 20.0 and agitation for 6.0 h at 80oC dissolve more than 79% of Th with only minimum of light rare earth elements as 2.8%.

However, the initial prepared thorium concentrate contains about 45% Th, the final concentrate contains more than 70% thorium which seems to be suitable to conduct further purification steps.