Potassium chloride sulphate removal

In a 500 ml. three-necked flask, equipped with a thermometer, a sealed Hershberg stirrer and a reflux condenser, place 32-5 g. of phosphoric oxide and add 115-5 g. (67-5 ml.) of 85 per cent, orthophosphoric acid (1). When the stirred mixture has cooled to room temperature, introduce 166 g. of potassium iodide and 22-5 g. of redistilled 1 4-butanediol (b.p. 228-230° or 133-135°/18 mm.). Heat the mixture with stirring at 100-120° for 4 hours. Cool the stirred mixture to room temperature and add 75 ml. of water and 125 ml. of ether. Separate the ethereal layer, decolourise it by shaking with 25 ml. of 10 per cent, sodium thiosulphate solution, wash with 100 ml. of cold, saturated sodium chloride solution, and dry with anhydrous magnesium sulphate. Remove the ether by flash distillation (Section 11,13 compare Fig. II, 13, 4) on a steam bath and distil the residue from a Claisen flask with fractionating side arm under diminished pressure. Collect the 1 4-diiodobutane at 110°/6 mm. the yield is 65 g. 

The experimental details for mono-M-propylanillne are as follows. Reflux a mixture of 230 g. of aniline and 123 g. of n-propyl bromide for 8-10 hours. Allow to cool, render the mixture alkafine, and add a solution of 150 g. of zinc chloride in 150 g. of water. Cool the mixture and stir after 12 hours, filter at the pump and drain well. Extract the thick paste several times with boiling light petroleum, b.p. 60-80° (it is best to use a Soxhlet apparatus), wash the combined extracts successively with water and dilute ammonia solution, and then dry over anhydrous potassium carbonate or anhydrous magnesium sulphate. Remove the solvent on a water bath, and distil the residue from a Claisen flask with fractionating side arm (well lagged). Collect the n-propyl-aniline at 218-220° the yield is 80 g. Treat the pasty solid zincichloride with an excess of. sodium hydroxide solution and steam distil 130 g. of pure aniline are recovered. 

SRS skids have been proposed for a number of different types of sulphate removal operations, including sodium sulphate from sodium bromide solutions, sodium chlorate solutions and potassium sulphate from potassium chloride solutions. All of these different separations have been tested on a commercial spiral-wound membrane and the results have been good. 

The kelp is crushed into lumps—say, one to two inches diameter—and extracted with water in rectangular iron vats with false bottoms, heated by steam. The liquid of sp. gr. 1 200 to l-255 is decanted into open iron boiling pans where it is evaporated down to a sp. gr. of 1 325 the salts—mainly potassium sulphate (50-60 per cent.) mixed with sodium sulphate and chloride—which separate by crystallization during the evaporation are removed. The hot liquid is run into cooling vats where crystals of potassium chloride separate. The liquid is again boiled down, and crystals consisting mainly of sodium chloride with 8 to 10 per cent, of sodium carbonate—and called kelp salt-—separate from... 

Esters. The most common impurities are the corresponding acid and hydroxy compound (i.e. alcohol or phenol), and water. A liquid ester from a carboxylic acid is washed with 2N sodium carbonate or sodium hydroxide to remove acid material, then shaken with calcium chloride to remove ethyl or methyl alcohols (if it is a methyl or ethyl ester). It is dried with potassium carbonate or magnesium sulphate, and distilled. Fractional distillation then removes residual traces of hydroxy compounds. This method does not apply to esters of inorganic acids (e.g. dimethyl sulphate) which are more readily hydrolysed in aqueous solution when heat is generated in the neutralisation of the excess acid. In such cases, several fractional distillations, preferably under vacuum, are usually sufficient. 

Salting Out. — A very valuable method to induce substances dissolved in water to separate out is known as salting out. Many substances soluble in pure water are insoluble or difficultly soluble in an aqueous solution of certain salts if, therefore, sodium chloride, potassium chloride, potash, calcium chloride, ammonium chloride, Glauber s salt, sodium acetate, ammonium sulphate, or other salt is added to the solution, this is dissolved, and the substance previously in solution separates out. By this method many compounds like alcohol, acetone, etc., which are so easily soluble in water that they cannot be removed from it by extraction with ether, can be separated out with ease. The method of procedure is this One of the above-mentioned salts, usually solid potash, is added to the solution until no more will dissolve. The substance... 

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