Abstract: The invention relates to a process for producing simultaneously food-grade and fodder-grade phosphoric acid by crystallizing phosphoric acid hemihydrate, H3PO4×0.5H2O, from a prepurified feed acid, which is purified and crystallized with the help of the following steps, a) after the step of froth-flotation of phosphate concentrate, the concentrate is directed to a strongly magnetic separation step in order to decrease the Mg ion amount, b) the phosphate concentrate is leached in a mixture of sulfuric acid and phosphoric acid according to the wet process, the precipitated SO4 and As ions are removed, and a silicon source is added in order to adjust the F/Si molar ratio to <6, c) the phosphoric acid is concentrated, the solids precipitate is removed, and the F ions are evaporated, d) the feed acid obtained from step c, having a concentration of >58% P2O5, solids concentration of <0.05%, Mg ion concentration of <1.

Abstract: The invention relates to a process for the separation of phosphate minerals from a phosphate ore, especially from a phosphate-carbonate ore, by using in the flotation as the reagent selective for phosphate mineral a compound having the general formula I, or a salt or amide ##STR1## of the same, in which formula X is --CH--CH--, ##STR2## Y is ##STR3## n is a number 0-40, in which case, when n is greater than 1, groups ##STR4## may be the same or different, m is 0 or 1, B is --NRR.sup.2 or, when m and n are 0, ##STR5## R is H, R.sup.3 or ##STR6## and R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5, which may be the same or different, each stand for an aromatic, araliphatic or straight-chain or branched aliphatic hydrocarbon which contains 1-30 carbon atoms and which is possibly substituted by an oxygen or nitrogen function, with the exception of sulfosuccinic acid monolkyl amide according to Formula I. The invention also relates to such a reagent.

Abstract: A process for the separation of phosphate minerals from a phosphate-carbonate ore, by flotation, wherein a phenol polymer such as a resol or a novolak, which improves the yield and selectivity of the phosphate minerals with respect to the carbonate minerals, is used in addition to a collector agent in the flotation.

Abstract: A process for the separation of phosphate minerals from a phosphate-carbonate ore, by flotation, wherein a phenol polymer such as a resol or a novolak, which improves the yield and selectivity of the phosphate minerals with respect to the carbonate minerals, is used in addition to a collector agent in the flotation.