Abstract: In-situ solution mining method of an ore bed, particularly containing trona, which comprises exposing to a solvent an ore region inside a borehole drilled in the ore, and dissolving a desired solute within the exposed region to provide a liquor and create a voided ‘undercut’, such undercutting making the ore susceptible to gravitational loading and crushing. Unexposed ore falls into the undercut by gravity without breaking the ore roof resulting in exposure of fresh ore to the solvent and in preventing solvent exposure to contaminating material near the roof. The desired solute is eventually dissolved away in the entire bed from its floor up to its roof. Solvent injection may be delivered through a conduit positioned inside the borehole, and may be moved by retracting or perforating the conduit. The method may employ an advancing undercut initiated up-dip and traveling down-dip, or a retreating undercut initiated down-dip and traveling up-dip.

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: Process for producing sodium bicarbonate for purifying flue gases, according to which an aqueous solution containing sodium sulfate is subjected to electrodialysis to produce a sodium hydroxide solution and a sodium bisulfate solution, the sodium hydroxide solution being carbonated in order to obtain sodium bicarbonate.

Abstract: Process for the joint production of sodium carbonate and sodium bicarbonate out of trona, comprising introducing and dissolving crushed trona ore is introduced and dissolved in a leaching tank containing a solution comprising sodium carbonate and sodium bicarbonate, saturated in sodium bicarbonate, in order to produce solid particles suspended in a production solution comprising sodium carbonate, the solid particles containing insoluble impurities and at least 65% in weight of sodium bicarbonate; separating the solid particles from the production solution containing sodium carbonate; drying and valorizing the separated solid particles; taking at least part of the production solution containing sodium carbonate out of the leaching tank in order to constitute a produced solution which is valorized; and introducing water in the leaching tank.

Abstract: In-situ solution mining method of an ore bed, particularly containing trona, which comprises exposing to a solvent an ore region inside a borehole drilled in the ore, and dissolving a desired solute within the exposed region to provide a liquor and create a voided ‘undercut’, such undercutting making the ore susceptible to gravitational loading and crushing. Unexposed ore falls into the undercut by gravity without breaking the ore roof resulting in exposure of fresh ore to the solvent and in preventing solvent exposure to contaminating material near the roof. The desired solute is eventually dissolved away in the entire bed from its floor up to its roof. Solvent injection may be delivered through a conduit positioned inside the borehole, and may be moved by retracting or perforating the conduit. The method may employ an advancing undercut initiated up-dip and traveling down-dip, or a retreating undercut initiated down-dip and traveling up-dip.

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: Process for producing sodium bicarbonate for purifying flue gases, according to which an aqueous solution containing sodium sulfate is subjected to electrodialysis to produce a sodium hydroxide solution and a sodium bisulfate solution, the sodium hydroxide solution being carbonated in order to obtain sodium bicarbonate.

Abstract: In a process to produce sodium carbonate, a first production solution comprising sodium carbonate is introduced into less basic compartments of an electrodialyser comprising alternating less basic and more basic adjacent compartments separated from each other by cationic membranes, the more basic compartments being delimited by anionic faces of bipolar membranes on one side and by the cationic membranes on the other side; a second production solution comprising sodium carbonate is introduced into the more basic compartments of the electrodialyser; a solution comprising sodium hydroxide is produced into the more basic compartments by combination of sodium ions flux sodium ions crossing the cationic membrane and hydroxyl ions flux crossing the anionic face of the bipolar membranes, and is then extracted from the electrodialyser to be used as a reaction solution; and the reaction solution is reacted with sodium bicarbonate in order to form a produced solution comprising sodium carbonate.

Abstract: In a process to produce sodium carbonate and/or sodium bicarbonate from an ore mineral comprising sodium bicarbonate, a production solution comprising sodium carbonate is introduced into less basic compartments of an electrodialyser comprising alternating less basic and more basic adjacent compartments separated from each other by cationic membranes, the more basic compartments being delimited by anionic faces of bipolar membranes on one side and by the cationic membranes on the other side; a solution comprising sodium hydroxide is produced into the more basic compartments by combination of sodium ions flux crossing the cationic membrane and hydroxyl ions flux crossing the anionic face of the bipolar membranes, and is then extracted from the electrodialyser to be used as a reaction solution; the reaction solution is put into contact with the mineral ore to form a solution comprising sodium carbonate; and the solution comprising sodium carbonate is divided into a part used as the production solution and a rema

Abstract: Process for the joint production of sodium carbonate and sodium bicarbonate crystals, according to which: 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; 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

Abstract: Process for the joint production of sodium carbonate and sodium bicarbonate out of sesquicarbonate, in which the sesquicarbonate is dissolved in water, in order to form a feed water solution comprising both sodium carbonate and sodium bicarbonate, in which at least part of the feed water solution is introduced into all the compartments of an electrodialyser and in which a sodium bicarbonate enriched solution and a sodium carbonate enriched solution are extracted from the compartments.

Abstract: The electrolyser comprises vertical electrodes (8, 9) and a stack of vertical frames (1, 2) made of a flexible material, deployed freely over the periphery of the electrodes and elastically deformed by compression one against another between two end flanges (3, 4).The invention applies to membrane electrolysers for the electrolysis of aqueous sodium chloride solutions.

Abstract: Electrolysis cell incorporating, in an enclosure, electrodes (17) each of which passes, in a leaktight manner, through an individual opening (16) in a wall (4) of the enclosure and each of which is surrounded by an individual bag-shaped tubular separator (20) engaged in a leaktight manner in the abovementioned opening in the wall.