Abstract: Apparatus for the separation of a solid salt by-product from the product gaseous hypohalogenated acid of a reactor is disclosed which is effective to separate particles ranging in size from about 0.5 to about 50 microns. The reactor mixes an aqueous alkali metal hydroxide and a gaseous halogen to produce the hypohalogenated acid product and solid salt by-product which are discharged from the reactor into the separation apparatus.

Abstract: A process for controlling the concentration of aluminum in the brine of a membrane chlor-alkali cell is disclosed wherein the brine has its calcium carbonate settler solids digested in the calcium chloride flow stream by the addition of an inorganic mineral acid to bring the pH to about 2.0 to about 3.0 to solubilize the aluminum in the brine. The brine has the pH adjusted upwardly to reprecipitate the aluminum onto carrier particles and then removes the reprecipitated aluminum and carrier particles from the brine by filtration or centrifugation.

Abstract: A process for purifying an alkali metal halide brine containing aluminum as an impurity which comprises adjusting the pH of the alkali metal halide brine to the range of from about 8.5 to about 9.5 and contacting the alkali metal halide brine with an ion exchange resin having a phosphonic acid group.Using the novel process of the present invention, high purity alkali metal halide brines may be produced for use in electrolytic membrane cells which have concentrations of aluminum reduced to a level which will not cause damage to a cation exchange membrane or affect the membranes ability to transport cations or water molecules.

Abstract: Disclosed is a method of determining which membrane in a multiple unit filter press membrane electrolytic cell is structurally damaged after cell operating conditions and monitorings indicate the problem exists.