Reactor for separation of sodium chloride and potassium chloride from polymineral sources and method thereof

A method of separation of sodium chloride and potassium chloride from a polymineral source containing sodium and potassium chlorides, comprising the following steps:

• (i) feeding a pre-ground polymineral source into an upper zone of a vertical three-zone reactor filled with a sodium chloride and potassium chloride saturated solution, wherein a temperature between −2.5° C. and −20° C. is maintained in the upper zone of the vertical three-zone reactor,
• (ii) recrystallizing sodium chloride to form sodium chloride dihydrate crystals and separating the formed sodium chloride dihydrate crystals from potassium chloride crystals by flotation to produce a froth containing the potassium chloride crystals, wherein the sodium chloride dihydrate crystals fall down to a middle zone of said vertical three-zone reactor,
• (iii) multistage sizing of the sodium chloride dihydrate crystals by an upward flow of a liquid phase and simultaneous multistage countercurrent washing of the sodium chloride dihydrate crystals falling down to the middle zone by the upward flow of the liquid phase, wherein the upward flow velocity is equal to a flotation velocity of sodium chloride dihydrate crystals whose hydrodynamic diameter is greater than a maximum hydrodynamic diameter of particles of the polymineral source by not less than 20 microns;
• thus, after the simultaneous multistage countercurrent washing, allowing the sodium chloride dihydrate crystals to enter a lower zone of the vertical three-zone reactor, provided that the hydrodynamic diameter of the sodium chloride dihydrate crystals entering the lower zone of said vertical three-zone reactor exceeds the maximum hydrodynamic diameter of the particles of the polymineral source by at least 20 microns,
• (iv) recrystallizing, after the simultaneous multistage countercurrent washing, the sodium chloride dihydrate crystals into anhydrous sodium chloride in the lower zone of the vertical three-zone reactor filled with a sodium chloride saturated solution, in which lower zone a temperature between 0.5° C. and 15° C. is maintained to produce a suspension of anhydrous sodium chloride.