Process and apparatus for recovering alcoholic phosphoric acid solutions from acid phosphates

摘要

Alcoholic phosphoric acid solutions are produced from acid phosphates or phosphate mixtures in the presence of water and a strong mineral acid by extraction with water. To this end, an aqueous phosphate solution or suspension is contacted countercurrently and thereby mixed with a mixture of at least one alcohol having from 3 to 8 carbon atoms and a strong mineral acid, the alcohol or alcohol mixture and the phosphate solution or suspension being used in a ratio by volume of 2:1 to 20:1, and the mineral acid being used in the quantity just necessary to transform the phosphates approximately quantitatively to phosphoric acid. The alcohol or alcohol mixture, mineral acid and phosphate solution or suspension contain the quantity of water necessary to ensure the formation of a mixture consisting of an alcoholic phase and a separate flowable salt phase, which is separated from the alcoholic phase.