METHOD FOR PRODUCING GRANULATED SORBENTS AND INSTALLATION FOR CARRYING OUT THE METHOD

摘要

The invention relates to a method for producing granulated sorbents, and to an installation for carrying out the method. The aim of the invention is to obtain the chloride form of the double hydroxide of aluminium and lithium as LiCL2AI/OH)3 nH2O (DHAL-CL) in a waste-free solid phase of aluminium hydroxide and lithium salts in a mixer, with subsequent continuous activation of crystalline DHAL-CI in a centrifugal mill activator in order to obtain a defectuous material structure. The product obtained is mixed with chlorinated polyvinyl chloride as a binding agent and with liquid methylene chloride. The granulation is carried out by extruding the paste produced and refining the same in the granulator. The methylene chloride produced is collected by an organic liquid absorbent having a high boiling point. The methylene chloride steam is guided out of the material flow in the carrier gas flow in the manner of an ideal displacement in the counter-current of the contact phases. The methylene chloride recuperation is carried out in two steps according to the thermal method, during the heating of the absorbent used. The inventive method is characterised by essentially reduced environmental impact in relation to prior art, due to the closed material circuits used. The granulated sorbent is especially suitable for the selective extraction of lithium from chloride salt lye of any mineralisation, with an extraction degree of 95 %.