Abstract: The action of the bacterium Nitrobacter agilis to oxidize nitrite ions to nitrate ions in aqueous solutions is well known. We have found that if the nitrite ion concentration in solution is maintained at a level of at least 2.5 percent by weight and higher, that the activity of this bacterium is completely inhibited and the nitrite salt solutions remain stable over long periods of time.

Abstract: Sodium (bi)sulfites are produced by the steps of:(a) introducing a stream of aqueous sodium carbonate into the top end of a main packed column reactor;(b) introducing a stream of sulfur dioxide gas into the top end of the main packed column reactor concurrently with the stream of aqueous sodium carbonate;(c) allowing the aqueous sodium carbonate and sulfur dioxide to cocurrently flow downward from the top end of the main packed column reactor to the bottom of the column in a cocurrent flow, during which flow reaction occurs between the aqueous sodium carbonate and the sulfur dioxide to produce sodium (bi)sulfite; and(d) recovering the product sodium (bi)sulfite and a gas stream containing any excess sulfur dioxide from the bottom of the main packed column reactor. The product (bi)sulfite can be separated from the gas stream in a separate receiving vessel and then the gas is sent to a scrubber to remove residual SO.sub.2. The scrubber may be a second packed column reactor operating with cocurrent flow.

Abstract: Permanganate based fabric bleaching processes, such as stone-washing processes, are substantially improved by utilizing a reducing composition comprising a metabisulfite and a sulfite in the washing step. The relative amounts of metabisulfite and sulfite in the reducing composition are selected so as to substantially eliminate the odor of sulfur dioxide during the washing step at the particular temperature selected. For washing temperatures of 100.degree.-140.degree. F. the preferred weight ratio of sodium metabisulfite to sodium sulfite is 7:3, which produces a reducing composition having a pH of 6.2 (in a 5% by weight solution). Such a composition not only allows operation at elevated temperatures without an odor of SO.sub.2, it also allows a reduction in the washing time and in the amount of reducing composition used.

Abstract: An improved process for the manufacture of sodium metabisulfite is provided. In this process, the chemical reaction forming sodium bisulfite solution is carried out separately from the crystallization of sodium metabisulfite. The crystallization step is carried out without chemical alteration and without pH adjustment.

Abstract: Permanganate based fabric bleaching processes, such as stone-washing processes, are substantially improved by utilizing a reducing composition comprising a metabisulfite and a sulfite in the washing step. The relative amounts of metabisulfite and sulfite in the reducing composition are selected so as to substantially eliminate the odor of sulfur dioxide during the washing step at the particular temperature selected. For washing temperatures of 100.degree.-140 .degree. F. the preferred weight ratio of sodium metabisulfite to sodium sulfite is 7:3, which produces a reducing composition having a pH of 6.2 (in a 5% by weight solution). Such a composition not only allows operation at elevated temperatures without an odor of SO.sub.2, it also allows a reduction in the washing time and in the amount of reducing composition used.

Abstract: Calcium nitrate with low nitrate content is prepared by reacting in a series of absorption reactors lime slurry and nitrogen oxide gases. The lime slurry flows serially through the series of absorption reactors with a major portion being recycled to the inlet of a Venturi absorber in each reactor. Nitrogen oxide gases flow cocurrently with the slurry from each reactor to the following Venturi inlet and are contacted by recycle slurry in each Venturi with a molar ratio of calcium hydroxide to nitrogen oxides of at least about 20. Slurry from the last reactor with a calcium nitrite content of below about 22 weight percent and a calcium hydroxide content of at least about 2 weight percent may be freed of unreacted calcium hydroxide, for example by treatment with NO.sub.x gases, and then concentrated to the desired product concentration. The exit gases may be scrubbed with incoming lime slurry after passing through a holdup vessel which increases the ratio of NO.sub.2 to NO.

Abstract: There is disclosed a process for storing energy by use of the heat of fusion of hydrated salts which are within a bulk container having heat exchange means. The process prevents stratification and supercooling from occurring during the heat releasing cycles by internally circulating the molten salt within the container and also by preventing the temperature of the salt from rising above that at which complete melting of the salt crystals within the container occurs.

Abstract: A concentrated calcium fluoride ore, having a decreased foam value which is particularly adapted for the manufacture of hydrogen fluoride is provided by a process which comprises: (a) grinding calcium fluoride ore containing calcite and quartzite particles to form calcium fluoride particles and to liberate at least a portion of said calcite and quartzite particles; (b) admixing the ground ore with aqueous medium and an effective amount of a suitable flotation agent to form a first aqueous slurry containing said flotation agent and calcium fluoride, calcite and quartzite particles; (c) contacting said first aqueous slurry with a gas under conditions sufficient to produce (i) a foam containing a major portion of said flotation agent and foamed particles comprising calcium fluoride particles together with a minor portion of the calcite and quartzite particles in said first slurry, and (ii) separated solids containing a major portion of the calcite and quartzite particles in said first slurry; (d) recovering at l

Abstract: A process for the production of high purity calcium thiosulfate by a metathesis reaction of ammonium thiosulfate and calcium hydroxide or calcium oxide is disclosed. Aqueous solutions of high purity calcium thiosulfate, in concentrations up to about 30% by weight, are prepared by removing substantially all of the co-product ammonia under conditions which minimize the decomposition of the thiosulfate ion. Heating the reaction mixture to a temperature of about the boiling point at atmospheric pressure is used to prepare aqueous solution of about 10% by weight calcium thiosulfate, and lower reaction temperatures are employed to prepare more concentrated aqueous solutions of calcium thiosulfate up to about 30% by weight, which is the saturation point.

Abstract: Improvement in the method for making a sulfur dioxide-containing gas stream of low elemental sulfur content by contacting a stream of oxygen-containing gas with elemental sulfur maintained above its auto-ignition temperature to generate a gas stream containing sulfur dioxide and gaseous elemental sulfur, followed by contacting this gas stream with liquid elemental sulfur maintained below its auto-ignition temperature, which improvement involves subsequently scrubbing the gas stream in a confined area with water or an aqueous medium, preferably containing small amounts of ammonia, under conditions of turbulent flow to obtain a sulfur dioxide-containing gas stream substantially free of oxygen and sulfur trioxide and containing less than about 0.0002 lb. of sulfur per cubic foot of gas, measured at standard conditions.

Abstract: Improvement in the process for making sodium metabisulfite by contacting a suspension of sodium carbonate in countercurrent stream with sulfur dioxide, which involves passing sulfur dioxide-containing gas sequentially through a first and a second reaction vessel, maintaining an acidic aqueous slurry of sodium metabisulfite in the first reaction vessel and a strongly alkaline aqueous slurry of sodium carbonate in the second reaction vessel, continuously feeding sodium carbonate to the second reaction vessel, passing strongly alkaline slurry from the second reaction vessel to the first reaction vessel and overflowing excess liquid from the first reaction vessel to the second reaction vessel, and recovering sodium metabisulfite crystals from the slurry in the first reaction vessel.