Abstract: In a process for purifying raw brine containing dissolved strontium, calcium and magnesium impurities wherein the raw brine is treated by contacting the brine with sodium carbonate for precipitation of strontium and calcium carbonate, contacting the brine containing the strontium and calcium carbonate solids with sodium hydroxide for precipitation of magnesium hydroxide, and removing strontium carbonate, calcium carbonate and magnesium hydroxide solids from the sodium chloride brine, the improvement which comprises passing at least a portion of said removed solids to the zone wherein the raw brine is contacted with sodium carbonate.

Abstract: A method of producing finely-divided phosphor grade calcium carbonate having a calcite crystalline structure and a very low sodium content. The calcium carbonate is produced from calcium chloride having a high sodium impurity content, such as calcium chloride which is a by-product of the Solvay process for producing soda ash.

Abstract: A stable, homogeneous, and flowable soil neutralizing slurry of particulate material such as calcium carbonate or dolomitic lime as provided using a suspending agent and a dispersant. A polyanionic dispersant is used in limited quantities to increase the concentration of particulate material and a gelling grade clay mineral is used as a suspending agent to prevent settling of the dispersed particulate material. A partial dispersion technique is used whereby the amount of dispersant used is limited so that the particulate material is dispersed but not the clay mineral.

Abstract: A process is disclosed for removing impurities such as carbon dioxide, and sulfur dioxide from acidic fluid solutions using a serpentine material and producing a reaction product comprising recoverable metal values and finely divided silica. In accordance with the process, the serpentine material is slurried with water and is then mixed with an acidic fluid solution including at least one of H.sub.2 CO.sub.3 and H.sub.2 SO.sub.3. In particular, the acid material may be formed by contacting a gaseous component such as carbon dioxide or sulfur dioxide directly with water. A waste industrial gas containing carbon dioxide, sulfur dioxide, or a mixture of the two is an excellent source of gaseous components having utility in connection with this invention.

Abstract: Brine from a conventional treatment process is pre-filtered prior to the electrolysis of same by a method which includes the steps of: (a) heating the brine, (b) adding sodium carbonate thereto, (c) stirring the solution, (d) allowing the solution to settle, and (e) passing the solution through an absolute membrane filter. The filter "polishes" the brine feed by removing the high hardness ions.

Abstract: Calcium carbonate is manufactured by the carbonation of an aqueous suspension of calcium hydroxide in the presence of a complex-forming agent for calcium ions which is added subsequently to the primary nucleation stage, and preferably during a first carbonation stage. Optionally there is also added a long-chain fatty acid or long-chain fatty acid salt, preferably after a final carbonation stage.

Abstract: Chemical and aqueous components of sludge derived from lime treatments of raw water supplies are recovered by procedures involving carbonation of the sludges to effect a phase separation between magnesium and calcium components. When the magnesium content of the raw water is intolerable in the treated water, a magnesium carbonate is recovered from the liquid phase by its decarbonation, and the aqueous component of the liquid phase is recycled to recover the water values of the treated sludge. When the magnesium content of the raw water can be tolerated in the treated water, the liquid phase magnesium bicarbonate solution is recycled to the water treatment plant.

Abstract: Brine is purified prior to electrolysis by dividing it into two streams, removing sulfate from one of the streams by precipitation with calcium chloride to form calcium sulfate, removing the precipitate and re-combining the streams. Alkali hydroxide plus sodium carbonate are added to the re-combined streams to precipitate calcium carbonate which is removed. Any magnesium comes down as the hydroxide. The brine is then pure enough for electrolysis The calcium sulfate first precipitate is reacted with sodium hydroxide and carbon dioxide to form calcium carbonate which is then reacted with hydrochloric acid to form calcium chloride which is recycled to the process for precipitating calcium sulfate.

Abstract: This invention relates to a process for the treatment of the reaction mass produced during the joint elimination of barium-containing nitrite-/nitrate-bearing carburizing salt wastes and cyanide-/cyanate-bearing wastes by ignition of the dry mixture at elevated temperatures, comprising suspending the reaction mass in water and either (a) adding a water-soluble barium salt to the aqueous suspension in equimolar quantities, based upon carbonate ions, and separating precipitated barium carbonate, or (b) freeing the alkaline suspension from barium carbonate by filtration, reacting the filtrate with a water-soluble calcium salt, and separating precipitated calcium carbonate, concentrating the clear solutions obtained according to (a) or (b) to a water content of 10 - 20% by weight, separating precipitated sodium chloride, and evaporating the residual solution to dryness.

Abstract: This invention relates to a process for the treatment of the reaction mass produced during the joint elimination of barium-containing nitrite-/nitrate-bearing carburizing salt wastes and cyanide-/cyanate-bearing wastes by ignition of the dry mixture at elevated temperatures, comprising suspending the reaction mass in water and eitherA. neutralizing the alkaline suspension obtained with concentrated nitric acid to a pH value of 6, the feed velocity of the acid and conditions of agitation being so selected that the pH value of the suspension will at no time fall below pH 6, and separating the barium carbonate,OrB. freeing the alkaline suspension obtained from barium carbonate, and neutralizing the filtrate with concentrated nitric acid to a pH value of 7.2, the feed velocity of the acid and conditions of agitation being so selected that the pH value of the suspension will at no time fall below pH 7.

Abstract: This invention relates to a process for the treatment of the reaction mass produced during the joint elimination of barium-containing nitrite-/nitrate-bearing carburizing salt wastes and cyanide-/cyanate-bearing wastes by ignition of the dry mixture at elevated temperatures, comprising suspending the reaction mass in water and either (a) adding a water-soluble barium salt to the aqueous suspension in equimolar quantities, based upon carbonate ions, and separating precipitated barium carbonate, or (b) freeing the alkaline suspension from barium carbonate by filtration, reacting the filtrate with a water-soluble calcium salt, and separating precipitated calcium carbonate, concentrating the clear solutions obtained according to (a) or (b) to a water content of 10-20% by weight, separating precipitated sodium chloride, and evaporating the residual solution to dryness.