Abstract: An exhaust gas treating method removes sulfur dioxide from exhaust gas containing at least sulfur dioxide and mercury by bringing the exhaust gas into contact with absorption liquid. Persulfate is added into the absorption liquid or alternatively, iodine gas is added to the exhaust gas before the exhaust gas is brought into contact with the absorption liquid. A high removal rate for both sulfur dioxide and mercury is stably maintained if the load of power generation and the composition of exhaust gas fluctuate.

Abstract: An object of the present invention is to provide a method for recovering iodine, which can be carried out simply and economically without practicing mixing processing operation of iodine-containing material, an alkali metal compound and a solvent in advance before introducing to a combustion furnace. The object of the present invention can be attained by a method for recovering iodine which comprises feeding an iodine-containing solution containing iodine and/or iodine compound, a basic alkali metal compound solution and/or a basic alkaline earth metal compound solution separately to a roasting furnace, oxidatively decomposing a combustible material by heat treatment, and absorbing iodine and/or iodine salt contained in a component at heat treatment exit with water or an aqueous solution.

Abstract: A process for the preparation of chlorine and sodium sulphate which contains the steps of reacting sulphuric acid with sodium sulphate and ferric oxide or alumina, crystallizing and drying the resulting double salt trisodium-iron(III) sulphate or trisodium-aluminum sulphate and roasting the obtained trisodium-iron(III) sulphate or trisodium-aluminum sulphate with sodium chloride under the influence of oxygen thereby forming sodium sulphate, chlorine and ferric oxide or alumina.

Abstract: The advantages of the serial application of chlorine dioxide and chlorine without intermediate wash during the bleaching of wood pulp in the absence of significant amounts of dissolved organic materials are improved by the presence of small quantities of dissolved chlorine in the chlorine dioxide solution.

Abstract: The adverse effects of dissolved organic material in the aqueous phase of pulp suspensions during bleaching using mixtures of chlorine dioxide and chlorine are overcome by applying the chlorine dioxide and chlorine serially to the pulp in two steps without an intermediate wash. An aqueous solution of chlorine dioxide and chlorine in which the chlorine constitutes from about 6 to about 10% of the total available chlorine of the solution is used in the first step and chlorine is used in the second step. The aqueous solutions are formed by dissolving in water chlorine dioxide and chlorine formed in a chlorine dioxide generator.

Abstract: The advantages of the serial application of chlorine dioxide and chlorine without intermediate wash during the bleaching of wood pulp in the absence of significant amounts of dissolved organic materials are improved by the presence of small quantities of dissolved chlorine in the chlorine dioxide solution.

Abstract: The adverse effects of dissolved organic material in the aqueous phase of pulp suspensions during bleaching using mixtures of chlorine dioxide and chlorine are overcome by applying the chlorine dioxide and chlorine serially to the pulp in two steps without an intermediate wash. An aqueous solution of chlorine dioxide and chlorine in which the chlorine constitutes from about 6 to about 10% of the total available chlorine of the solution is used in the first step and chlorine is used in the second step. The aqueous solutions are formed by dissolving in water chlorine dioxide and chlorine formed in a chlorine dioxide generator.

Abstract: The advantages of the serial application of chlorine dioxide and chlorine without intermediate wash during the bleaching of wood pulp in the absence of significant amounts of dissolved organic materials are improved by the presence of small quantities of dissolved chlorine in the chlorine dioxide solution.

Abstract: The process of reacting a metallic halide (which metal is sodium, potassium or calcium) with sulfur trioxide including dispersing the metallic halide in the presence of an excess of sulfur trioxide or sulfur dioxide, as a dispersant, to enable handling the mixture as a slurry, completing the reaction to form the desired metallic halogen sulfonate, decomposing the metallic halogen sulfonate before or after an intermediate step to remove excess sulfur trioxide and sulfur dioxide, using combustion of sulfur to supply the heat to vaporize excess sulfur trioxide and sulfur dioxide present, and to decompose the metallic halogen sulfonate to yield the halogen, sulfur dioxide, and the sulfate of the metal, separating the metallic sulfate from the gaseous products, and separating the halogen from the sulfur trioxide and sulfur dioxide in the gaseous products by extractive distillation, or alternately treating organic material under anhydrous conditions with the metallic halogen sulfonate or its decomposition products,

Abstract: A process for the wet-treatment of an exhaust gas in which nitrogen oxide and sulfur oxide contained in the exhaust gas are removed by use of an absorbent comprising a lime slurry containing an alkali metal or alkaline earth metal iodide, wherein an oxidizing agent is supplied to at least a part of iodide containing liquid retrieved from the wet-treatment to oxidize the iodide and thereby recover said iodide as iodine.

Abstract: Combustion products, especially those from electric power generating installations burning high sulfur fuels are treated to remove solids and then to separate physically sulfur containing constituents, such as SO.sub.2 and/or SO.sub.3 from other gases in the combustion products mixture by means of an ultra high speed gas centrifuge or a gas cyclone. The recovered oxides of sulfur in a heated condition are utilized in any desired chemical reaction. For example, they may be passed over dry NaCl and reacted therewith to yield sodium sulfate and chlorine, both of which can be recovered, and/or they may be passed directly over suitable catalysts in the presence of air to produce a pure grade of sulfur trioxide which can be absorbed in water to manufacture concentrated sulfuric acid.