Abstract: The method and apparatus mixes two immiscible liquids A and O to form a dispersion and then pre-separates the dispersion into two fractions (A+o) and (O+a) in a spout. These two fractions are fed separately into a decanter with two separate compartments which continue to maintain the two fractions as separate. Within the two separate compartments the two fractions are further separated into two flows, A, O, a, and o, such that four flows exit the decanter.

Abstract: A process for the removal of substantially chromium free sulfate from aqueous alkali metal solutions containing chromate and sulfate which includes mixing the solutions while having a pH of between about 2.5 and 4.5 with a calcium-containing material for a time and at a temperature sufficient to form a gypsum precipitate and separating that precipitate from the solutions; as well as a process for the production of alkali metal chlorate by electrolysis of alkali metal chloride including the removal of chromium free sulfate.

Abstract: The present invention relates to a continuous process for the manufacture of potassium chlorate by coupling with a plant for the production of sodium chlorate by electrolysis, the said plant comprising a source of NaCl solution, (1), a loop for purification of the said solution (2--2', 3), an electrolysis device (4), a storage tank (5), if appropriate, and a crystallizer (6) in which the crystallization and the separation of NaClO.sub.3 crystals are preferably carried out, wherein circulating liquid is removed downstream of the said electrolysis device (4), a concentrated solution of potassium chloride is added to said liquid, precipitation (11) of the potassium chlorate is caused by any known means, the said potassium chlorate is separated off and the mother liquor from crystallization of the said potassium chlorate is recycled into the said purification loop (2--2', 3) of the sodium chlorate production plant.

Abstract: Mixer-settler apparatus of the reverse liquid flow type having at least one assembly which includes one or more mixers in series, each being fitted with stirrers and pumps, at least one settling tank in which liquids separate, and at least one submerged chute extending into the settling tank from a pump to convey the mixture of liquids from the pumps to the settling tank. The chute is constructed of enlarged dimensions which extend over a major portion of the width of the tank to facilitate a pre-settling action within the chute, and the chute extends a substantial distance into the settling tank to allow extended pre-settling time.

Abstract: The invention relates to a process and a solvent for extraction of the chromates present in an aqueous solution. According to the invention, the aqueous phase is brought into contact with an organic phase comprising 2 to 10% by volume of a solvent selected from the group of tertiary or quaternary amines and 15 to 40% of a solvent selected from the group of esters of phosphoric acid in a diluent based on petroleum hydrocarbons. The invention is applicable to the production of concentrated solutions of chromates easily recyclable from an extraction of the chromates contained in an industrial solution.

Abstract: In the illustrative embodiments of the invention disclosed, an installation for mixing and separating two non-miscible liquids includes, inter alia, an improved pump structure for raising the liquid dispersion from the mixing tank to the inlet level to the decanting tank, a low flat chute for conveying the dispersion from the mixing tank to the remote end of the decanting tank, height-controlling means for controlling the level of the interphase within the decanting tank, and provision for recycling the lighter liquid phase to the mixing tank.