Method for the preparation of lactic acid and calcium sulphate and calcium sulphate dehydrate.

摘要

Method for the preparation of lactic acid and calcium sulphate and calcium sulphate dehydrate.The invention relates to a method for the preparation of lactic acid and calcium sulphate.In which (a) an aqueous solution containing lactate is interacted with sulfuric acid at a temperature that is essentially larger than the transition temperature dehydrate calcium sulfate / semi- hydrated calcium sulphate (case ~ 4 ~.2H ~ 2 ~ / case ~ 4 ~ - 0,5h ~ 2 ~ the), to form a mixture which contains semi hydrated calcium sulfate and lactic acid.(b) the mixture of step (a) is subjected to at least one step of Recrystallization at a temperature that is lower than the transition temperature dehydrate calcium sulfate without /I - hydrated calcium sulphate dehydrate to form a precipitate of calcium sulfate and an aqueous solution of lactic acid.And (c) the precipitate of dehydrate calcium sulfate is separated from the aqueous solution of lactic acid.