Process for making a solid compound by precipitation, suspensions of solid in liquids and solids obtained by the process and their use as additives

A process for making a solid compound by precipitation, using a reactor comprised of a tank defining a mixing chamber having an inner wall which is generally symmetrical about a central axis, of an agitator comprising a cylindrical central portion extending in said mixing chamber along said axis and at least one blade having a twisted orientation on said central portion, of a series of first baffles extending along the inner wall generally parallel to said axis and of a series of second baffles extending along the inner wall generally transverse to said axis;

• and comprising the steps of
• (A) introducing a first fluid material containing a first reactant and a second fluid material containing a second reactant into said reactor in order to obtain a mixed fluid, rotating the agitator, disrupting the mixed fluid flow generally circumferentially in said mixing chamber with first baffles and disrupting the mixed fluid flow generally axially in said mixing chamber with second baffles, in order to cause the first reactant to react with the second reactant to form a solid compound by precipitation in the mixed fluid;
• (B) withdrawing the mixed fluid containing the precipitated solid obtained in step (A) from the reactor, and;
• (C) optionally separating the precipitated solid compound from at least one fraction of the mixed fluid.