Abstract: A method for removing organic materials from a wet process phosphoric acid obtained by treating an uncalcined phosphate rock with sulfuric acid. The wet process phosphoric acid is contacted with a reducing material having a standard single electrode potential of at most 1.42 V and then further contacted with active carbon.

Abstract: Ethyleneamines are efficiently recovered from an aqueous solution thereof by extracting them from the aqueous solution into an organic phase with an extractant selected from carbonyl group-containing organic solvents, benzyl alcohol, carboxylic acids and salts thereof, alkylphosphoric acids and salts thereof, and mixed solvents containing at least one of these extractants. The ethyleneamines in the organic phase is recovered preferably from the organic phase to the aqueous phase by incorporating an acid therein, followed by phase separation.

Abstract: A method for solvent extraction of phosphoric acid comprises counter-currently contacting an impure phosphoric acid solution containing at least 45 wt. % of P.sub.2 O.sub.5 with a partially water-miscible solvent in the presence of sulfuric acid, and which is characterized in that(a) as said solvent, a solvent in which from 3 to 10 wt. % of water is soluble, is used, and(b) sulfuric acid is added to a place where the H.sub.3 PO.sub.4 concentration in the aqueous phase is at most 3 mol./l so as to bring the relation between the free sulfuric acid concentration (Y (mol/l)) and the H.sub.3 PO.sub.4 concentration (X (mol/l)) in the aqueous phase of the same place to satisfy the formula5.0-0.83X.gtoreq.Y.gtoreq.2.5-0.83Xwithin the range of the H.sub.3 PO.sub.4 concentration in the aqueous phase being from 0.5 to 3 mol/l.

Abstract: A stable calcium hypochlorite composition and a method for the preparation thereof. The composition has a calcium hypochlorite anhydride and/or a calcium hypochlorite dihydrate used as main constituent and comprises at least 60 wt % of calcium hypochlorite; at least 5 wt % of calcium hydroxide; at least 4 wt % of water content; and 5 wt % or less of than that calcium chloride. The composition is stable and decomposes only in a less degree at a high temperature and during storage over a long period.

Abstract: A wet process phosphoric acid obtained by an solvent extraction method with n-butanol and/or isobutanol comprises(a) feeding a wet process phosphoric acid having a concentration of P.sub.2 O.sub.5 of higher than 35 wt. % into an extraction battery;(b) adding sulfuric acid into a stage in fifth or higher stage from the step of discharging an extracted solution and in second or higher stage from the step of discharging raffinate in the extraction battery at a gram equivalent ratio given by subtracting the amount of sulfuric acid in the wet process phosphoric acid fed into the extraction battery from 1.2 to 2.0 times of the sum of total cation impurities in the wet process phosphoric acid fed into the extraction battery and total components of sodium, potassium and magnesium added to the purification battery;(c) discharging said extracted solution having a concentration of H.sub.3 PO.sub.4 of 130 to 180 g.

Abstract: Wet process phosphoric acid prepared by treating phosphate rock with sulfuric acid is purified by extracting said wet process phosphoric acid with an organic solvent containing an equilibrium concentration of phosphoric acid in a first extraction section such that substantial extraction of phosphoric acid from said wet process phosphoric acid is prevented while the organic impurities in said wet process phosphoric acid are substantially extracted and under conditions which prohibit significant extraction of iron impurities into said solvent extractant, extracting the extracted wet process phosphoric acid of reduced organic impurity content with an organic solvent in a second extraction section, returning a portion of the solvent from the second extraction section to the solvent extraction phase of the first section, removing the organic impurities from the solvent phase which is obtained from the first extraction section, and returning at least a portion of the solvent from which the organic impurities have b

Abstract: A method of purifying extracted phosphoric acid containing substantially no metallic impurities which comprises:(a) adjusting the phosphoric acid concentration to from 20 to 65 wt.% as P.sub.2 O.sub.5,(b) adjusting the Si/F atomic ratio in said extracted phosphoric acid to less than 0.2; and(c) contacting said extracted phosphoric acid with silica gel at a temperature of 20.degree.-100.degree. C. to remove the dissolved silica from said extracted phosphoric acid; and(d) recovering extracted phosphoric acid having a reduced silica content.

Abstract: Wet process phosphoric acid prepared by treating phosphate rock with sulfuric acid and separating calcium sulfate, is purified to obtain a purified phosphoric acid by (a) an acid extracting section contacting the wet process phosphoric acid and a phosphoric acid solution containing impurities obtained in the scrubbing section with an organic solvent in the presence of the hydrochloric acid required for extracting a substantial amount of the phosphoric acid component; (b) a scrubbing section contacting the extract obtained in the acid extracting section with aqueous phosphoric acid or water while maintaining the chloride ion concentration in the aqueous phase in the range of 20 to 40 g/liter as Cl; (c) an acid stripping section contacting the purified extract obtained in the scrubbing section with water and (d) an adsorbing section contacting the extracted phosphoric acid obtained in the acid stripping section with an anion-exchange resin.

Abstract: A process for removing sulfate ions from extracted phosphoric acid which is substantially free of metallic ion impurities and which has been prepared by extracting wet process phosphoric acid with an organic solvent which comprises:A. adjusting the extracted phosphoric acid concentration to a concentration greater than 70%;B. adding an amount of a barium compound which is less than the stoichiometric equivalent amount of barium relative to the amount of dissolved sulfate ion to form barium sulfate crystals; andC. separating said barium sulfate from the resulting slurry at a temperature less than 80.degree. C and recovering purified, extracted phosphoric acid;Wherein the amount of barium compound added is such that said purified extracted phosphoric acid contains at least 5 ppm of sulfate ions.

Abstract: A process for removing organic material from extracted phosphoric acid comprises contacting extracted phosphoric acid with a chlorate and hydrochloric acid at a temperature higher than 100.degree. C while maintaining the concentration of the extracted phosphoric acid at a value higher than 90 wt% as H.sub.3 PO.sub.4. Hydrochloric acid may also be included with the chlorate.

Abstract: A process for removing sulfate ions from extracted phosphoric acid which is substantially free of metallic ion contaminants, which comprises adding less than the stoichiometric equivalent of a barium compound relative to the amount of dissolved sulfate ion to said extracted phosphoric acid to form barium sulfate crystals, adding active carbon to the resulting slurry, separating the solid components from the slurry and recovering purified phosphoric acid.