Abstract: This invention is concerned with compositions of granular sodium tripolyphosphate (STPP) and their manufacture, which are suitable for use in the manufacture of automatic dishwasher detergents. The granular STPP compositions contain an overall 30 to 40% by weight of the STPP Phase I modification and no more than 5% of the granules composing the composition shall be of both +50 mesh size and under 25% Phase I concentration. Particle size of the total composition is 10% maximum of both +20 mesh and -100 mesh fractions. Apparent density is 0.7 to 0.9 grams per cubic centimeter. Such compositions are made by using only STPP materials in the 30 to 40% range or by mixing -50 mesh fractions of lower Phase I material with coarser fractions of higher Phase I material so that Phase I content of the total mixture is 30 to 40%.

Abstract: A coating composition is provided which is suitable for the protection of corrodible metallic surfaces. The coating composition includes a binder and a filler, with the filler present in an amount sufficient to impart corrosion-resistant characteristics to the coating composition. The filler comprises conductive metal particles and particles of a metal composition which comprises silicon and at least one active metal. The metal composition can be an alloy of silicon with an active metal which is unstable when introduced alone into water or a silicide of an active metal which is unstable when introduced alone into water.

Abstract: A method is provided for extending the life of transition metal-based cathodes used in chlor-alkali diaphragm cells by adding a small amount of a reducing agent, such as Na.sub.2 SO.sub.3 or urea, to the electrolytic solution during periods of interrupted current flow to the cell. The reducing agent reacts with the sodium hypochlorite which is dissolved in the electrolytic solution to prevent the oxidation, and hence dissolution, of the transition metal in the cathode coating.

Abstract: A cathode for use in electrolytic processes and a process for preparing such cathodes is described. The cathode has a cathodically active surface comprising a codeposit of a first metal selected from the group consisting of iron, cobalt, nickel, and mixtures thereof, a leachable second metal or metal oxide preferably selected from the group consisting of molybdenum, manganese, titanium, tungsten, vanadium, indium, chromium, zinc, their oxides, and combinations thereof, and a third metal selected from the group consisting of cadmium, mercury, lead, silver, thallium, bismuth, copper and mixtures thereof. Such cathodes are prepared by initially forming a codeposit of the three metals or metal oxides, and subsequently removing at least a portion of the second metal or metal oxide from the codeposit. The second metal or metal oxide component can be conveniently removed by leaching, utilizing an alkaline solution.

Abstract: An improved electrolytic cell for the electrolysis of alkali metal halide solutions to produce halides and alkali metal hydroxides is provided wherein current reductions are obtained by the passage of an oxidizing gas, such as oxygen, into a porous cathode to depolarize the cathode and eliminate the porduction of hydrogen. The cathode is provided with small diameter pores for diffusion of said oxidizing gas, and larger diameter pores or holes for liquid product flow through the cathode. The cathode, separator, and anode may be in direct contact with each other in a sandwich configuration, thus eliminating the need for a catholyte compartment and external H.sub.2 O feed lines.

Abstract: A film-coated cathode is provided for the electrolysis of alkali metal halide solutions in the substantial absence of chromium ions. The cathode comprises a conductive substrate, such as titanium, steel, iron, or alloys thereof, coated with an adherent, porous film of a substantially nonconductive material having an average coating thickness of less than about 10.sup.3 microns. The nonconductive, film-forming material is further characterized as being chemically inert in the halate solution.

Abstract: A cellulosic pulp and bleaching process is described. The process integrates two cycles, one is a digestor liquor cycle and the other is a sulfur cycle.The digestor liquor cycle comprises the steps of digesting a fibrous cellulosic feed to form a pulp, separating the pulp and bleaching it in at least one stage with chlorine dioxide, evaporating and burning the remaining waste liquor to form a smelt, dissolving the smelt to form a green liquor and utilizing the green liquor, after recausticizing, as at least a portion of the feed stock for the digestor step.The sulfur cycle of the present invention utilizes a portion of the green liquor of the digestor liquor cycle. The green liquor is carbonated to form a bicarbonate which is then stripped of H.sub.2 S. The H.sub.2 S is converted into H.sub.2 SO.sub.4 and utilized as a feed stock to a chlorine dioxide generator. The chlorine dioxide generator utilizes H.sub.2 SO.sub.4 as feed stock and produces Na.sub.2 SO.sub.4 as a by-product. The Na.sub.2 SO.sub.

Abstract: An improved anode element for monopolar filter-press electrolysis cells comprises providing said anode element with an integral hollow member positioned above the upper surface of said anode element. Preferably, said hollow member is formed as an integral extension of the electrode frame, said hollow member having an outlet for withdrawing chlorine gas and being adapted to permit continuous fluid contact with said anode element, said hollow member being further adapted to provide sufficient hydrostatic pressure in said anode element for optimal liquid flow through the diaphragm over the entire operating cycle of the electrolysis cell.

Abstract: A method is provided for reducing waste stream pollutants by the control and separation of color bodies, COD, BOD and other organics from inorganic chloride pollutants in the aqueous waste effluent of a cellulosic pulp bleaching process containing a sequential chlorination stage (D.sub.c) or mixture (D/C) stage followed by an extraction (E) or oxygen (O) stage, comprising, maintaining the conditions of the D.sub.

Abstract: Apparatus and method for preparing phosphorus compounds wherein phosphorus vapor containing P.sub.2 molecules is condensed at a temperature below the solidification point of red phosphorus and the resulting solid is then reacted with a phosphorus-reactive material. When the phosphorus-reactive material is water at an elevated temperature, phosphine is produced.

Abstract: An apparatus for the manufacture of halate, such as sodium chlorate, includes an electrolytic cell having a plurality of anodes and cathodes, clearance passageways between which have electrolyte, hypohalite and gaseous electrolysis product, principally hydrogen, moving upwardly between them, an enclosure covering the tops of at least four such passageways and narrowing down to a passageway extending upwardly from the top of the enclosure and a downward passage for circulation of electrolyte which includes an upper baffled portion and a lower unbaffled portion, the unbaffled part being alongside the electrodes and extending to the bottom of the cell, from which electrolyte is drawn upwardly past the electrodes. Natural circulation due to gravity flow and density differences between the liquid electrolyte and that entrained in gas or having gas entrained in it is normally sufficient so that stirring or pumping means are not required.

Abstract: A method of operating a plurality of electrolytic diaphragm cells utilizing interruptable or off-peak electrical power varying from a higher electrical load level to a lesser electrical load level and subsequently returning to a selected higher electrical load level is described, which comprises the steps of:(a) reducing the brine feed into each cell in an amount at least about proportional to the scheduled electrical load reduction,(b) reducing the electrical load from a higher level to a lower level over a time period of not less than about 20 minutes,(c) operating the cells at such lower electrical load level until additional current is available, and, when additional current is available,(d) increasing the brine feed into each cell to between about 100 and about 150 percent of the original feed rate,(e) increasing the electrical load level to a selected higher level over a period of not less than about 10 minutes,(f) adjusting the brine feed to the original feed rate, and(g) maintaining the caustic concen

Abstract: The proportion of chlorine dioxide to chlorine in aqueous solutions formed from gaseous mixtures of chlorine dioxide and chlorine is improved over conventional separation techniques. The gaseous product stream from a chlorine dioxide generator is scrubbed with an aqueous salt mixture containing an approximately stoichiometric quantity of sodium hydroxide, which reacts preferentially with the chlorine, yielding chlorine dioxide of high purity. The absorption system is operated under such conditions that the chlorine is converted to sodium chlorate and sodium chloride, which may then be recirculated to the chlorine dioxide generating system. The scrubbing salt solution is adjusted so as to produce an R-2 mixture upon reaction with the chlorine in the chlorine/chlorine dioxide stream.

Abstract: Electrode elements are provided for monopolar electrolysis cells useful in chlor-alkali electrolysis and having two vertical, planar, opposed electrode surfaces, said surfaces being substantially parallel and spaced apart from one another and being electrically fastened to an electrode frame, said electrode element being characterized in that at least one electrode rod is connected in electrically conductive fashion to the side portion of said electrode frame, extending through the space between said opposed electrode surfaces substantially parallel to said electrode surfaces, the diameter of said rod being smaller than the distance between said opposed electrode surfaces, said electrode rod being provided with conductive members distributed over the length thereof and connected in electrically conductive fashion to both the electrode surfaces and the electrode rod.

Abstract: An improved process is provided for the production of chlorine dioxide and chlorine wherein a chlorine dioxide generator may be operated interchangeably in either sulfuric acid or hydrochloric acid mode without changing acidity levels or evacuating the liquor of one mode and refilling with liquor of the second mode before continuing generation. The versatile process for production of chlorine dioxide comprises maintaining saturated solutions of both alkali metal chloride and alkali metal sulfate in the generator at an acid normality of from about 2 to about 11 in the presence of a small amount of catalyst selected from the group consisting of vanadium pentoxide, silver ions, manganese ions, dichromate ions and arsenic ions. Thus, the instant process provides high yields of chlorine dioxide even at high acidities making it possible to manufacture balanced quantities of saltcake and alkali metal chloride by-products as may be required.

Abstract: A composite bipolar electrode structure is described. The structure includes an anode face comprised of a layer of a platinum group metal, metal oxide, or mixtures thereof, deposited on a layer of a valve metal, preferably titanium, a cathode face comprised of a cathode material, suitably a ferrous material, and an intermediate layer of conductive, porous material, such as graphite, positioned to be in electrical contact between the valve metal layer and the cathode material layer. The electrode is assembled by applying a thin layer of a polymeric material on the interfaces of the porous intermediate layers and pressing the components with sufficient pressure to force the polymeric material into the interstices of the intermediate layers.

Abstract: A cathode busbar structure is provided for an electrolytic cell which can enable the electrolytic cell to be designed to operate as a chlor-alkali diaphragm cell at high current capacities of about 150,000 amperes and upward to about 200,00 amperes while maintaining high operating efficiencies while in normal or jumpered operation. These high current capacities provide for high production capacities which result in high production rates for given cell room floor areas and reduce capital investment and operating costs.

Abstract: An improved electrolytic cell comprises the combination of a wide electrode, or more closely spaced electrodes, to achieve a narrow gap between electrodes, the electrodes being of conventional, simple, non-adjustable construction, guide spacers separating the anode elements and cathode elements of the electrolytic cell, and a hard, dimensionally stable, diaphragm.

Abstract: A continuous process for the manufacture of dialkyl dithiophosphoric acid from phosphorus pentasulfide and a lower alkanol through the use of a settling tube and a continuous process for the manufacture of dialkyl phosphorochloridothionate by chlorinating dialkyl dithiophosphoric acid with chlorine which has been diluted with an inert gas.

Abstract: An improved hollow bipolar electrode unit for use in an electrolytic cell is disclosed, comprising at least one connecting device within the hollow region of the electrode unit to provide mechanical support and electrical communication between the anode and cathode of such bipolar electrode.