Abstract: In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

Abstract: The invention relates to a method and to an arrangement for removing gaseous elementary mercury from a stream of gas and to an arrangement for carrying out the method. The arrangement comprises a first washing tower (2) for receiving a stream of gas, a second washing tower (6) for receiving a stream of once processed gas (5) from the first washing tower (2), and a third washing tower (9) for receiving a stream of twice processed gas (23) from the second washing tower (6) and configured for discharging a stream of cleaned gas (12).

Abstract: Disclosed is a boron recovering device including: an aeration-type water-channel reactor including a water channel; at least one aeration unit disposed in the water channel and aerating a boron-containing solution by passing it through the water channel to deposit boron in the form of borax; and a precipitation bath precipitating the deposited borax in the boron-containing solution having passed through the aeration-type water-channel reactor and separating a filtrate by overflowing, a boron recovering device, a method of recovering boron, and a boron recovering system.

Abstract: Process for the joint production of sodium carbonate and sodium bicarbonate crystals, according to which: a solid powder derived from sodium sesquicarbonate, having a mean particle diameter comprised between 0.1 and 10 mm is dissolved in water; the resulting water solution is introduced into a crystallizer, wherein a first water suspension comprising sodium carbonate crystals is produced; the first water suspension is subjected to a separation, in order to produce crystals comprising sodium carbonate on the one hand, which are valorized, and a mother liquor on the other hand; and a part of the mother liquor is taken out of the crystallizer and put into contact in, a gas liquid contactor, with a gas comprising carbon dioxide, in order to produce a second water suspension comprising sodium bicarbonate crystals, which are separated and valorized. A reagent powder comprising sodium bicarbonate crystals made by such process.

Abstract: The present invention provides a method and apparatus for removing mercury from gases such as those discharged from roasters and other heat producing systems. In embodiments the method comprises reacting the mercury with dissolved molecular chlorine, and may also comprise reacting the mercury with mercuric chloride to yield mercurous chloride. The mercurous chloride may be removed by precipitation. There are also disclosed apparatuses for implementing the method.

Abstract: A process for producing sodium bicarbonate from a sodium carbonate bearing stream (A) comprising sodium carbonate and an alkaline metal salt impurity at a concentration Ci(A), comprising: a) mixing the stream (A) with part of a stream (B), b) bicarbonating the resulting mixed stream with a gas comprising CO2 to produce an aqueous suspension comprising sodium bicarbonate crystals (F), c) separating the sodium bicarbonate crystals (F) from the aqueous liquor (G), d) partly debicarbonating at least part of (G) and removing part of the water of (G) to obtain the stream (B) with the salt impurity at a concentration Cf(B), e) recycling part of the stream (B) to step a) so that the ratio of the concentrations Cf(B)/Ci(A) of the impurity is at least: 1.4, and f) removing the remainder (I) of the stream (B) or the remainder (J) of the liquor (G) to be further processed.

Abstract: A process for producing sodium bicarbonate from a sodium carbonate bearing stream (A) comprising at least 2% sodium chloride and/or sodium sulfate by weight, a part of such stream (A) being generated by a sodium carbonate crystallizer, comprising: a) mixing the stream (A) with part of a stream (B) to produce a stream (C); b) bicarbonating the stream (C) with a gas (D) comprising CO2 to produce an aqueous suspension (E) containing crystals (F) comprising sodium bicarbonate crystals; c) separating the aqueous suspension (E) to obtain crystals (F) comprising sodium bicarbonate crystals and an aqueous mother liquor (G); d) partly debicarbonating such liquor (G) and removing part of the water to obtain the stream (B) and an optional gas (H); e) recycling at least part of the stream (B) to step a); and f) removing the remainder of the stream (B) or part of the aqueous mother liquor (G) to be further processed.

Abstract: A process for producing sodium bicarbonate from a sodium carbonate bearing stream (A) comprising sodium carbonate and an alkaline metal salt impurity at a concentration Ci(A), comprising: a) mixing the stream (A) with part of a stream (B), b) bicarbonating the resulting mixed stream with a gas comprising CO2 to produce an aqueous suspension comprising sodium bicarbonate crystals (F), c) separating the sodium bicarbonate crystals (F) from the aqueous liquor (G), d) partly debicarbonating at least part of (G) and removing part of the water of (G) to obtain the stream (B) with the salt impurity at a concentration Cf(B), e) recycling part of the stream (B) to step a) so that the ratio of the concentrations Cf(B)/Ci(A) of the impurity is at least: 1.4, and f) removing the remainder (I) of the stream (B) or the remainder (J) of the liquor (G) to be further processed.

Abstract: A method for producing sodium carbonate monohydrate, according to which an aqueous sodium chloride solution (5) is electrolyzed in a membrane-type cell (1) from which an aqueous sodium hydroxide solution (9) is collected, and carbonated by direct contact with carbon dioxide (15) to form a slurry of crystals of a sodium carbonate monohydrate (16), and the slurry or its mother liquor is evaporated (3) to collect sodium carbonate monohydrate (18).

Abstract: The present invention involves a system and method of making ferric chloride with reduced amounts of hydrochloric acid for water treatment. The method comprises preparing a reactant batch comprising ferric oxide and hydrochloric acid at a predetermined molar ratio. The method further includes mixing the reactant batch with an impeller rotating between about 60 and 150 revolutions per minute. The method further includes maintaining the reactant batch at a temperature between about 70° Fahrenheit and 180° Fahrenheit. The method forms a reaction product including ferric chloride and a reduced amount of hydrochloric acid.

Abstract: Method for producing sodium carbonate, according to which an aqueous sodium chloride solution (5) is electrolyzed in a membrane-type cell (1) from which an aqueous sodium hydroxide solution (9) is collected, and carbonated by direct contact with carbon dioxide (15) to form a slurry of crystals of a sodium carbonate (16), and the slurry or its mother liquor is evaporated (3) to collect sodium carbonate (18).

Abstract: An aqueous solution of sodium chloride is electrolyzed in a cell (1) with an ion permselective membrane to produce, on the one hand, chlorine (16) which is converted in a chlorine production unit (6) and, on the other, an aqueous sodium hydroxide solution (19), which is carbonated using a flue gas (13) from an electricity and steam cogeneration unit (5), and the resulting carbonated solution (18) is evaporated to produce sodium carbonate crystals (21).

Abstract: The invention relates to a process for the production, by fluid-bed spray granulation, of granular sodium percarbonate having a low TAM value. According to the invention, in the fluid-bed spray granulation, an Mg compound in a quantity of 50 to 2,000 ppm, in particular 100 to 1,000 ppm, or/and a complexing agent from among the hydroxycarboxylic acids, aminocarboxylic acids, aminophosphonic acids and phosphonocarboxylic acids, hydroxyphosphonic acids and their alkali metal salts, ammonium salts or Mg salts, in a quantity of 50 to 2,000 ppm, in particular 200 to 1,000 ppm, are added as stabilisers to the soda solution and/or H2O2 solution. Preferably a combination of an Mg compound in a quantity of 100 to 1,000 ppm Mg2+ and waterglass in a quantity of 0.1 to 1 wt. %, in particular 0.1 to 0.5 wt. %, is used, and in this case granules having a TAM value of about or below 6 ?W/g and simultaneously a short dissolving time, are obtainable.

Abstract: A process for destroying alkali metal and alkaline earth metal-containing wastes, such as sodium, by feeding such waste into a molten bath containing a molten salt such as sodium carbonate, or a mixture of salts having a lower melting point, such as a mixture of sodium carbonate and an alkali metal halide, e.g. sodium chloride, or mixtures of alkali metal chlorides, feeding a mixture of carbon dioxide and oxygen into the molten salt bath and reacting the alkali metal or alkaline earth metal such as sodium in the waste with the carbon dioxide and oxygen to form alkali metal carbonate, e.g. sodium carbonate, in the molten salt bath.

Abstract: The present invention relates to a method and process for recovering solid sodium bicarbonate, from the effluent, of the cathode compartment of a diaphragm cell that contains sodium hydroxide and sodium chloride. The effluent is treated with carbon dioxide and ammonia to essentially convert the sodium hydroxide to sodium bicarbonate. Thereafter, the effluent is treated to decompose the ammonium chloride to evolve and recycle ammonia without the formation of pollutants, the treated effluent, free of NH.sub.3, CO.sub.2 and alkali, is resaturated and sent to the anode compartment of the diaphragm cell. In preferred embodiments, all of the steps are interconnected and the materials produced are recycled, such that the only products produced are chlorine, hydrogen and sodium bicarbonate, without waste products in a continuous process.

Abstract: Production of sodium bicarbonate from natural soda deposits that may occur as natural brines or solid soda salts is disclosed. The alkalinity in these natural soda deposits consists of carbonates and bicarbonates. The carbonates are converted to bicarbonates by reacting sodium carbonate with ammonium bicarbonate which acts as a carbon dioxide carrier until all the sodium carbonate is exhausted. The solubility of the sodium bicarbonate is lowered by the presence of non-alkaline sodium salts, e.g., sodium chloride. The regeneration of the cyclic reagent (NH.sub.3) is done using the sodium bicarbonate formed by the double decomposition of sodium chloride and ammonium bicarbonate giving a final soda free brine exempt of contaminants foreign to its original components.

Abstract: The present invention adds carbonates or chlorides of alkaline earth metals to the radioactive wastes containing sodium sulfate and subjects sulfate group in the radioactive wastes to reduction treatment, thereby converts the sulfate group into sulfides of alkaline earth metals which are chemically stable substances while suppressing SOx generation, and solidifies the radioactive wastes stably for an extended period of time by applying to the converted radioactive wastes solidifying treatment.

Abstract: Process for separating sulphate from a contaminating chromium component contained in an aqueous liquor by the crystallization of a sulphate compound. The sulphate may be separated substantially free of chromium component by adjustment of the pH to the range of from about 2.0 to about 6.5, followed by cooling of the liquor to precipitate the sulphate compound from solution which sulphate is subsequently removed. The process provides an effective method for the separation of sulphate from dichromate, and is particularly useful in the production of chlorate.

Abstract: Process for the production of a water-insoluble nitrogeneous organic base, from an aqueous solution of alkali metal bicarbonate and the base hydrochloride, according to which the solution (11) is treated with a complement of the base hydrochloride (12), and the resultant liquid (18) is treated with a basic agent (30) capable of decomposing the hydrochloride. The invention is applied to the regeneration of the amine in the process for the manufacture of sodium bicarbonate by the amines method.

Abstract: This invention is related to a process for the secondary obtention of sodium carbonate from a waste liquor (known as FLP waste liquor) containing principally sodium chloride, ammonium bicarbonate, ammonium chloride and carbon dioxide, which is obtained in the filtering section within the solvay process for the primary obtention of sodium carbonate, by adding a compound or a mixture of compounds sodium ions to the FLP waste liquor in the presence of carbon dioxide, in order to precipitate sodium bicarbonate therefrom, and treating the precipitation and sodium bicarbonate to obtain the secondary production of sodium carbonate.

Abstract: A method is disclosed of producing a liquid agent for improving the quality of contaminated water, particularly water in pools, natural bodies of water and waste waters, characterized by introducing with agitation comminuted rock-salt clay or a mixture thereof with rock-salt deads into an aqueous solution or suspension of an inorganic base, stirring the resultant mixture for 2 to 5 (preferably 3) hours, thereupon adjusting the pH of the resultant solution to a value of between 7.5 and 10.5 (and preferably between 9.5 and 10.5) by means of the addition of acid or alkali, and removing undissolved portions from the solution.

Abstract: A process for the production of sodium carbonate wherein sodium bicarbonate is recovered from a brine containing sodium carbonate by carbonation of the brine under controlled conditions. The sodium bicarbonate is crystallized from the carbonated brine in a multi-stage carbonating, cooling and crystallization process after which it is filtered to produce wet cake. The wet cake is subjected to predrying to provide a predried wet cake of a specified free moisture content and mixed with recycle light ash to provide a dryer feed of specified moisture content to alleviate problems of product fouling or plugging of the dryer. The light ash from the dryer then is bleached and subjected to recrystallization, screening, centrifuging and drying to provide a dried sodium carbonate possessing, after evaporation of the water of hydration and free moisture, less than 0.10 percent moisture and chemical and physical properties meeting commercial dense ash specifications.

Abstract: A method for enhancing recovery of sodium carbonate from sodium carbonate solutions which contain sodium chloride. Anhydrous sodium carbonate is recovered in good yields from aqueous sodium carbonate solutions containing sodium chloride by evaporative crystallization at superatmospheric pressure and at a temperature of at least about 120.degree. C.

Abstract: Production of sodium bicarbonate by the Solvay-soda method, employing a volatile aliphatic amine instead of ammonia, is combined with the oxychlorination of olefins in liquid phase by using the amine hydrochloride side-product of the soda plant as chlorine source in the oxidative regeneration of the spent chlorinating liquid. The chlorinating liquid contains iodine and copper chloride or iron chloride and on regenerating the spent liquid the amine is recovered in the vapor phase and recycled to the soda plant.

Abstract: An aqueous hypochlorous acid production process is disclosed wherein the precipitate formed upon carbonating electrolytic cathode cell liquor is contacted in a fluidized bed with a mixture of gaseous chlorine and water vapor and the exit gas from the fluidized bed is absorbed in water.

Abstract: A method for the recovery of ammonia from liquor from the filters of ammonia-soda plants, which contains free ammonia and ammonium chloride. In this method the liquor is heated to release the free ammonia, and the remaining liquor is then treated successively in a prelimer with lime in an amount insufficient to decompose the whole part of the ammonium chloride and in a still with steam and an alkali metal hydroxide in an amount sufficient to decompose the remaining part of ammonium chloride.

Abstract: Process and apparatus for producing bicarbonates by converting sodium hydroxide to sodium carbonate and reacting the sodium carbonate with carbon dioxide in a gas-liquid exchange and solid discharge zone and then in a gas-liquid exchange and solid discharge zone with cooling means, with possible recirculation, whereby bicarbonate is formed and precipitated in the first zone and bicarbonate formation is completed and precipitated in the second zone.

Abstract: An improved process for the treatment of precipitator catch wherein the catch is slurried with water, sufficient carbon dioxide is added to convert the sodium carbonate present to sodium bicarbonate, and sodium chloride is separated from the sodium sulfate and sodium bicarbonate.

Abstract: An improved process for the treatment of precipitator catch wherein the catch is slurried with water, sufficient carbon dioxide is added to convert the sodium carbonate present to sodium bicarbonate, and sodium chloride is separated from the sodium sulfate and sodium bicarbonate.

Abstract: A method for collecting a solid product from a liquid phase or liquid phase-gaseous phase feed stock. A solid forming zone is provided for accommodating the liquid phase or liquid phase-gaseous phase feed stock having a density greater than that of a liquid to be fed. A precipitation zone is provided at its lower portion with a feed port for feeding the liquid and a discharge port for taking out the solid product and communicating with the solid forming zone at its upper portion. The precipitation zone is provided therein with stirring means by which the solid product and liquid are contacted with each other countercurrently. The solid product is washed with the liquid and the density relation between the liquid phase and the liquid is reversed as the latter moves upwardly in the precipitation zone. Solid oxamide may be produced from cyanogen.