Abstract: A process for reducing arsenic levels in a solution containing sulfuric acid, water, and arsenic acid by adding copper or a copper-containing compound to the solution to form dissolved copper arsenate, adding alkali solution to precipitate the copper arsenate and to neutralize arsenic and sulfuric acid. The copper arsenate is separated, and the remaining solution is treated with a ferric compound and an alkali in order to form ferric arsenate to remove residual arsenate. The ferric arsenate is separated and the remaining solution contains less than about 0.79 ppm arsenic. The ferric compound is added so that the ratio of iron to arsenic is about 8:1 to about 10:1 and alkali is added during this step to adjust the pH to from about 5 to about 7.

Abstract: Sodium carbonate having a high bulk density and pseudo-cubic crystal structure is prepared from impure trona purge liquors from the crystallizers containing high concentration of organics, silica and sulfate by a sequence of steps involving (1) treatment of the liquors with MgO; (2) separation of the treated liquor from the insoluble reaction products; (3) addition of Ca and Mg compounds to the liquor; (4) evaporating the solution to obtain sodium carbonate monohydrate crystals; (5) separating the crystals from the mother liquor; and (6) heating the crystals at temperature of about 150.degree.-200.degree. C. to convert to dense ash.

Abstract: This invention relates to a process for conditioning the surfaces of natural and synthetic plastic materials for electroless plating of a metal coating thereon by exposing such materials to an atmosphere comprising an effective amount of ozone and thereafter contacting said exposed materials with an effective amount of a conditioning solvent, such as an aqueous solution of sodium, potassium or lithium hydroxide.

Abstract: This invention relates to a process for conditioning the surfaces of natural and synthetic plastic materials for electroless plating of a metal coating thereon by exposing such materials to an atmosphere comprising an effective amount of ozone and thereafter contacting said exposed materials with an effective amount of a conditioning solvent, such as an aqueous solution of sodium, potassium or lithium hydroxide.

Abstract: A process for the production of low organic, low silica, anhydrous sodium carbonate comprising (a) calcining raw trona ore to produce crude sodium carbonate containing soluble and insoluble impurities, (b) admixing said crude sodium carbonate with a substantially saturated sodium carbonate solution to produce sodium carbonate monohydrate crystals containing insolubles and an impure sodium carbonate solution; (c) separating these monohydrate crystals and impurities; (d) dissolving the monohydrate crystals to produce a substantially saturated sodium carbonate solution and insolubles; (e) separating said solution from the insolubles; (f) evaporative crystallization of the separated saturated sodium carbonate solution to produce pure sodium carbonate monohydrate crystals; (g) optionally, subjecting the crystals recovered in step (f) to steps (d-f) once, but no more than once; (h) heating said monohydrate crystals to obtain low organic, low silica, anhydrous sodium carbonate product particles; and (i) optionally,

Abstract: A method for production of absorptive particles of Wegscheider's Salt (Na.sub.2 CO.sub.3.3NaHCO.sub.3) having low bulk density and acceptable flow properties, by reaction of anhydrous sodium carbonate particles with water and carbon dioxide is disclosed. Particles of anhydrous sodium carbonate having a bulk density less than about 750 g/l are contacted with water up to 1.55 times the stoichiometric amount of water required for the formation of sodium carbonate monohydrate. Carbon dioxide is added in two stages; in the first, the reaction zone is maintained at ambient temperatures, the second, the reaction zone is preheated and the reaction temperature is maintained at between about 90.degree. and 105.degree. C. until at least about 50 weight percent Wegscheider's Salt is produced. Water is added to the carbon dioxide in the second stage if less than about 1.20 times the stoichiometric amount of water is added to the particles of anhydrous sodium carbonate in the first stage and when about 1.20 to 1.

Abstract: A method for dissolving calcined trona containing calcareous impurities, to obtain an aqueous sodium carbonate solution having low calcium content involves contacting calcined trona in countercurrent flow, desirably under specific temperature conditions, with dilute sodium carbonate solution. Sodium carbonate solutions thus obtained have reduced tendency to form calcium deposits in processing equipment.

Abstract: Conversion of sodium sesquicarbonate particles to particles of lower bulk density, as low as 180 grams per liter, with high absorption property capable of absorbing as much as 40 percent of wetting agent and with good resistance to breakage and attrition and with mild alkalinity of less than 9.9 pH to a pH approaching 9.4 without loss of particulate identity, by passing the particles through a reaction zone at a temperature of 70.degree. to 105.degree. C. and introducing a gas mixture containing 15-85 percent CO.sub.2 and 15-80 percent water vapor and maintaining the gas mixture in contact with the particles until the particles contain at least 10 percent Wegscheider's Salt and continuing the reaction to produce particles containing 20 to in excess of 95 percent Wegscheider's Salt with a water content of less than 12 percent, said particles being characterized by being in needle-form which in turn are composed of randomly oriented Wegscheider's Salt micro needles.

Abstract: Soda values from the crystallizer mother liquor purge in the process of making sodium carbonate from trona are recovered by (1) mixing the purge with treating agent of magnesium oxide, aluminum oxide, bauxite, certain fine particle size calcined trona, insoluble impurities obtained in the trona-soda ash process, or mixtures thereof, (2) evaporating the resulting mixture to dryness and calcining it to insolubilize soluble silicates and to reduce contamination with carbonaceous impurities, and (3) leaching the calcined mixture with water or aqueous sodium carbonate solution.

Abstract: In the process for making sodium carbonate from trona, the soluble silicate content of crystallizer mother liquor from which sodium carbonate precursor crystals are obtained by evaporative crystallization is reduced by digesting the mother liquor at elevated temperature in the presence of certain activated insolubles, followed by separating the insolubles from the digested mother liquor. These activated insolubles are obtained by calcining crushed trona, dissolving the calcined trona in an aqueous medium to obtain a solution of sodium carbonate containing insolubles, separating the insolubles and activating them by calcination at elevated temperature.

Abstract: In the process for making sodium carbonate from trona, the soluble silicate content of crystallizer mother liquor from which sodium carbonate precursor crystals are obtained by evaporative crystallization is reduced by the method which comprises:1. digesting said mother liquor at elevated temperature for time sufficient to reduce soluble silicates, in the presence as treating agent of insolubles which have been obtained by (a) calcination of crushed trona, (b) segregation of a fine particle size fraction from the calcined trona, (c) dissolution of said fine particle size fraction in an aqueous medium to obtain a solution comprising sodium carbonate and insolubles, followed by (d) separating insolubles, and2. separating the insolubles from the digested mother liquor, and recycling the mother liquor to the process.

Abstract: In the process of making sodium carbonate from trona involving the steps of crushing the trona, calcining the crushed trona, dissolving the calcined trona to obtain a solution comprising sodium carbonate and insoluble impurities contaminated by soluble silicates and soluble carbonaceous matter, contamination of the sodium carbonate solution with soluble carbonaceous matter is reduced by the improvement which comprises calcining the crushed trona at temperature of 300.degree. C. to 600.degree. C. in the presence of magnesium oxide. When the trona is calcined in the presence of magnesium oxide at temperature of 350.degree. to 600.degree. C., then the sodium carbonate solution is low in both soluble carbonaceous matter as well as insoluble silicates.

Abstract: In the process of making sodium carbonate from trona by the method involving crushing the trona, calcining it and dissolving it in an aqueous medium for purification by crystallization, soluble silicate contamination of the crystallization liquor is reduced by an improvement which involves: (a) segregating the calcined trona into a coarse and a fine fraction; (b) separately dissolving the coarse and fine fractions to obtain aqueous solutions of sodium carbonate, sodium silicates and insoluble impurities; (c) optionally adding to the solution of the fine fraction insoluble impurities which have been separated from a solution of such fine fraction in a previous operation; followed by (d) digesting the solution of the fine fraction containing added insolubles at elevated temperature to insolubilize soluble silicates and separating the digested solution from insoluble impurities.

Abstract: In the process of making sodium carbonate from trona involving the steps of crushing the trona, calcining the crushed trona, dissolving the calcined trona to obtain a solution comprising sodium carbonate and insoluble impurities contaminated by soluble silicates and soluble carbonaceous matter, contamination of the sodium carbonate solution with soluble silicates is reduced by the improvement which comprises calcining the crushed trona at temperature of 200.degree. C. to 600.degree. C. in the presence of an additive selected from the group consisting of aluminum oxide and bauxite. When the trona is calcined in the presence of aluminum oxide or bauxite at temperatures of 350.degree. to 600.degree. C., then the sodium carbonate solution is low in both soluble silicate as well as carbonaceous matter.

Abstract: Soda values from the crystallizer mother liquor purge in the process of making sodium carbonate from trona are recovered by (1) mixing the purge with treating agent of magnesium oxide, aluminum oxide, bauxite, certain fine particle size calcined trona, insoluble impurities obtained in the trona-soda ash process, or mixtures thereof, (2) evaporating the resulting mixture to dryness and calcining it to insolubilize soluble silicates and to reduce contamination with carbonaceous impurities, and (3) leaching the calcined mixture with water or aqueous sodium carbonate solution.

Abstract: Low bulk density products containing at least 10% Wegscheider's Salt, by weight, in needlelike form are produced from sodium bicarbonate by heating in the presence of a slow inert gas stream an aqueous feed mixture comprising, by weight, at least about 50% sodium bicarbonate and about 15 to 30% Wegscheider's Salt.

Abstract: Low bulk density products containing at least 10% Wegscheider's Salt (Na.sub.2 CO.sub.3.3NaHCO.sub.3), by weight, in needlelike form are produced from sodium bicarbonate by heating in two distinct steps an aqueous feed mixture comprising by weight at least about 50% sodium bicarbonate and about 3 to 25% Wegscheider's Salt.