| abstract |
The essential feature of the process according to the invention lies in that solid crystalline matters, respectively precipitates are gained from the solution by means of chemical reactions, in such a manner, that at least one of the components, the ions, forming the precipitate being slightly soluble in the liquid medium or inducing respectively promoting the chemical reaction between the compounds being present in the solution, is introduced into the system bound to the ion-exchange material, while this material serving as an ion-exchange auxiliary phase, is brought into contact with the solution containing the other component(s) forming the precipitate, or the ion-exchange materials containing individually the components forming the precipitate are brought together in a liquid medium and by the partial recirculation and/or by bringing repeatedly into contact with the ion-exchange auxiliary phase and the solution, the grain size of the precipitate can be increased, simultaneously filtrability may also be improved. The essence of the equipment being suitable for the realization of the process according to the invention lies in, that within the apparatus-body spaces are formed by means of partitions lying perpendicularly to the material stream, in the bottom there are the apertures interconnecting said spaces, while in the upper third of the partitions studs -protruding into the confining space and being connected to gas - or air distributing organs - are arranged; in the bottom of the single spaces means for distributing the gas or air are to be found; further on, the equipment is provided with an aerolift with a passage opening leading to the last space of the apparatus; the apparatus is futhermore provided with studs for the discharge of the material and outlets for the gas and air. The advantage of the invention lies in, that precipitates with an increased grain size, tending to a spontaneous flocculation may be obtained, simultaneously the purity of the precipitates formed is far higher, than that of the precipitates having been gained in course of usual processes. |