Abstract: Method of crystallizing from aqueous solution an inorganic solute, whose solubility in water varies relatively litter with temperature such that crystallizing by adjustment of temperature results in low yield, such method comprising contacting a concentrated aqueous solution of the solute with a hydrophilic organic solvent at a temperature T.sub.1, T.sub.1 and the organic solvent being selected such that at T.sub.1 a water-rich phase is formed in which the ratio of solute to water is less than the ratio found in the incoming aqueous solution, resulting in formation of crystals of solute. The resulting wet, organic-rich phase is separated and dried by contact with a concentrated aqueous solution of the solute at T.sub.2. T.sub.2 differs from T.sub.1, preferably being less than T.sub.1 if the solute dissolves exothermically in water and preferably being greater than T.sub.1 if the solute dissolves endo- thermically in water. The resulting dried organic phase is recycled to the crystallizing zone.

Abstract: Method of treating an aqueous solution of a non-volatile inorganic solute to produce a more concentrated solution or to crystallize solid solute from the solution. The solution is contacted at a higher temperature T.sub.1 with a suitable organic liquid to extract water and form an organic phase (organic liquid contacting water). The organic phase, separated, cooled and contacted at a lower temperature T.sub.2 with a drying medium to dry the organic liquid which is then re-used to treat a further quantity of aqueous solution. The drying medium may be a portion of the concentrated aqueous solution resulting from the first step, or it may be a concentrated aqueous solution or a slurry from an outside source, or it may be a combination of two such drying media.

Abstract: Method of concentrating aqueous solutions of non-volatile, ionic solutes by extracting water from the solution by means of a polar organic liquid (or a solution of a polar organic liquid and a non-polar organic liquid) at an elevated temperature and cooling the organic liquid to separate a water phase, the extractant and the temperatures being chosen such that water has a relatively high solubility in the extractant at the higher temperature and a relatively low solubility at the lower temperature; the extractant being also chosen to meet certain other criteria such as inertness toward the solution and equipment. Advantage is taken of the diminished activity coefficient of water in polar organic liquids at elevated temperatures and in the case of certain solutions, advantage is also taken of the increased activity coefficient of water in aqueous ionic solution at elevated temperatures.

Abstract: An electrostatic precipitator which operates on the principle of mutual repulsion of charged particles to a grounded wall. The solid particle laden gas stream enters a collecting section where additional particles in the form of droplets, normally water, are injected in the form of a fine spray into the solid particle laden gas stream. The solid particles and the additional particles are electrostatically charged either by conventional corona or by injecting the droplets from a charged nozzle and as the charged particles pass through the grounded section of the precipitator, a fraction of the water particles and solids are forced to the grounded wall by electric fields created by the space charge. Precipitated solid particles are entrained in the coalesced water which runs down the walls and is drained from the precipitator. Several stages of precipitation may be used or alternatively, methods such as continuously injecting additional particles into the collector along its length.