Abstract: A compact, heavy duty mixer-reactor is described which features a double-stage mixing/reaction chamber, one stage being of wall-baffled design and the other being unbaffled. Said mixer-reactor operates with a unique, two-stage impeller having a different set of coextensive agitator blades within each of said stages. For example, the effective radii of the blades in said unbaffled stage are significantly larger than those of the blades in said baffled stage. In addition, other differences in shape and pitch of the respective sets of agitator blades are provided to give enhanced performance, particularly in mixing and reacting finely divided solids with gases. The subject apparatus delivers outstanding results in terms of expediting thorough mixing and promoting complete reactions between fine solids and gaseous reagents. These results are particularly noteworthy when treating non-Newtonian suspensions of solids and liquids (e.g.

Abstract: Improved mixing equipment of the wall-baffled, cylindrical, mixing-vessel type is provided. The novel baffles employed have a uniform cross-sectional form corresponding generally to a small geometric segment of a circle, the radius of which circle is substantially equal to that of the inner wall of said mixing vessel. A plurality (e.g., 2 to 4) of such baffles mounted at uniformly spaced locations around the periphery of said inner wall are employed together with a concentrically located, multi-bladed impeller capable of providing good axial and radial mixing within said vessel.The subject mixing equipment can deliver outstanding performance in terms of speed and completeness of mixing, as well as economy in power consumption and peak power requirements. Results are especially noteworthy when the equipment is used to mix chemical reagents (gaseous or liquid) with thick, non-Newtonian suspensions of solids and liquids; e.g., wet wood pulps and similar compositions containing fine, fibrous solid matter.

Abstract: An elasticized, dispersion-grade vinyl chloride resin powder is provided which not only imparts improved elasticity and reduced hysteresis losses to fluid plastisols made therewith, but also has excellent stability under adverse environmental conditions, insuring consistent performance in plastisols even after said powder has been in storage for several months. This resin powder has an average particle size between about 0.4 and about 4 microns and contains between about 0.5 and about 20% by weight of an elastomeric acrylic polymer having a T.sub.g below about -10.degree. C. which is present as discrete particles most of which are at least partly occluded by hard thermoplastic vinyl chloride polymer formed in situ, which vinyl chloride polymer represents substantially all of the remaining mass of said powder.Fluid plastisols prepared from said resin powder are also described as well as finished articles of improved resiliency and elasticity, which are made from said plastisols.

Abstract: A safe continuous process is disclosed for generating superatmospheric pressure mixtures of chlorine and chlorine dioxide, wherein the chlorine dioxide is generated in situ by chemically reducing inorganic chlorates in aqueous sulfuric acid solutions, and most of the chlorine is supplied from a high-pressure external source. The mixed gaseous products contain Cl.sub.2 and ClO.sub.2 in volumetric Cl.sub.2 /ClO.sub.2 ratios of at least 10/1, and preferably between about 11/1 and 99/1, and are ideally suited for direct use in various industrial treatments, notably in the purification and bleaching of wood pulp and the like.

Abstract: A continuous system, process and associated apparatus are disclosed for reacting a gas with a liquid to manufacture a gaseous or liquid product. The preferred system comprises a reactive gas, such as chlorine and an aqueous solution, such as caustic soda, which are continuously combined and reacted under largely superatmospheric pressure and in turbulent cocurrent flow in very compact reactor equipment. Liquid bleach solutions such as aqueous solutions of hypochlorites or hypochlorous acid are among the products of major interest. The main reactor equipment consists of a fluid pressure energized, in-line mixing device followed by a low slip (closely fitted) regenerative turbine pumping unit. The fluid ports in the closely fitted stator elements of said pumping unit should have a radial dimension equal to at least about half that of the vanes.

Abstract: A disinfection process is provided for preparing potable water having an unusually persistent and long lasting free available chlorine residual in order to assure safety and integrity of said water during its passage through the distribution system by which it is delivered to the consumer. The key step of this process is the generation of said unusually persistent free chlorine residual by mixing into a semi-finished water, which has already been pretreated specifically to satisfy substantially its immediate chlorine demand, dilute solution of HOCl having a pH between about 3 and about 6.

Abstract: A cathode for the electrolysis of brine for the production of chlorine and caustic soda, whereby chlorate ions are produced, comprises a coating of e.g. Nickel alloyed with a metallic sacrificial component, the latter being leached out by a soltuion of sodium hydroxide. The remaining sodium hydroxide within the pores of the leached nickel coating is transformed into iron hydroxide upon application of an iron salt onto the nickel coating. The iron hydroxide acts as a suppressor for the excessive formation of chlorate ions in the caustic soda solution of the electrolysis cell.

Abstract: A solid polymer electrolyte (SPE), solid polymer electrolyte electrode, and method for forming from cationic exchange perfluorocarbon copolymer. Disclosed are solution techniques for forming SPE's and SPE electrodes using fluorocarbon vinyl ether copolymers.

Abstract: A bipolar electrolyzer is provided which includes a plurality of bipolar electrode sub-assemblies which position the electrodes in the cells in a manner such that improved electrical operating characteristics are achieved. Each bipolar electrode sub-assembly includes an alternating stack of electrically insulating spacer members and bipolar electrodes. Electrodes are horizontally received in a channel in the electrically insulating spacer members which fixes the spaced relationship between juxtapositioned anodes and cathodes.

Abstract: A blend of fluorocarbon polymers for incorporation into an asbestos fiber slurry for forming into a diaphragm is disclosed. The blend comprises fluorocarbon polymer fibers and fluorocarbon polymer chunks of certain sizes in certain weight ratios. Also disclosed is a diaphragm comprised of the asbestos and two types of fluorocarbon polymers, as well as a method of making same.

Abstract: A method for rendering an aluminum electrowinning cell component fabricated from an aluminum nonwettable material wettable by molten aluminum, and therefore utilizable within the cell. Under the method, the component is coated with titanium and boron, and while the component is immersed in molten aluminum within the cell, the molten aluminum is maintained near saturation with boron and titanium.

Abstract: Transition metals of the groups IVB, VB and VIB or alloys thereof with Al are electrodeposited in a system of an electrolyte based on an aromatic hydrocarbon. The electrolyte is originally prepared by dissolving 0.02 to 0.2 moles of an inexpensive high oxidation state transition metal halide and 0.2 to 0.5 moles AlBr.sub.3 in 1.00 mole of the aromatic hydrocarbon. Additions of transition metal powders or Mg or Al particles lead to the pre-reduction of the high oxidation state transition metal ions to lower oxidation states. Alkali metal or Mg halides may be used to establish favorable bath conditions. The electrolysis is carried out with dissolvable metal anodes, to maintain the bath composition. The plating current density, bath composition and method of preparation are chosen to obtain the desired composition of the coatings.

Abstract: A cathode coating comprises a catalyst for hydrogen evolution finely dispersed in a matrix consisting of an insoluble, semiconducting polymer which is formed in situ on an electrode support body. A bipolar electrode is provided with such a cathode coating on a support body consisting of a valve metal such as titanium.The cathode coating is formed by applying to the electrode support body a coating solution which contains an inorganic precursor compound for the hydrogen evolution catalyst and an organic precursor compound for forming the polymer matrix, drying and then thermally converting these precursors to a cathode coating adhering to the electrode support body.

Abstract: A substantially non-consumable anode used in the production of aluminium from a cryolite-based fused bath containing alumina consists of a sintered self-sustaining ceramic oxide body of spinel structure which is made conductive by selective partial substitution, the introduction of non-stoichiometry or by doping so as to maintain the impurities in the produced aluminium at low levels. Preferred materials are partially-substituted nickel ferrite spinels.

Abstract: A narrow gap electrolysis cell has anode and cathode compartments divided by an ionically-permeable separator, such as an ion-exchange membrane or a fibrous diaphragm, and a current feeder grid in electrical contact with a surface-activated particulate electrocatalytic material carried on a face of the separator. The particulate material has cores of a corrosion-resistant material preferably valve metal particles or sponge, or compounds thereof, as well as asbestos fibres and fibres of ion-exchange copolymeric perfluorocarbons, coated with a platinum-group metal catalyst in metal or oxide form. The surface-activated particles may be at least partly carried by a flexible electronically conductive foil between the current feeder grid and the separator.

Abstract: A method of making a catalytic lead-based oxygen-evolving anode comprises catalytically activating titanium sponge particles larger than 300 microns by impregnating with a solution containing Mn and Ru compounds, in amounts corresponding to Mn/Ru in an atomic ratio between 70/30 and 90/10, and thermally converting the compounds to an electrocatalyst comprising Mn and Ru in oxide form. Catalytic Ti sponge particles with up to 3 wt % Ru are thus produced, which are then uniformly distributed on the surface of a lead anode base in an amount greater than 400 g/m.sup.2, pressed, and partly embedded, thereby firmly anchoring and electrically connecting them to the lead anode base. The catalytic lead-based anode thus produced operates with oxygen evolution on the catalytic particles at a reduced potential at which the lead base remains electrochemically inactive. It thereby operates with significant energy savings over an extended service life.

Abstract: An electrode having a lead base and a catalyst is manufactured by (a) compressing titanium sponge particles so as to consolidate them to a coherent porous layer, (b) applying the catalyst to the titanium sponge particles, and (c) fixing the layer of consolidated sponge particles to the lead base. The catalyst is formed on the titanium sponge particles before or after their consolidation to a coherent layer. This layer may be produced and fixed to the base in a single compressing and fixing step combining (a) and (c). Oxygen is anodically evolved at a reduced, stable potential by means of this electrode, so that it can be usefully applied as an anode in processes for electrowinning metals from acid electrolytes.

Abstract: A method for repairing perfluorocarbon copolymeric cation exchange membranes. A quantity of a perfluorocarbon copolymer having a desired pendant cation exchange functional group is partially solvated in a solvating dispersion media, applied to areas of the membrane to be repaired, and the dispersion media removed.

Abstract: The disclosure is directed to preparing three-layer laminated electrodes suitable for use as oxygen (air) cathodes in chlor-alkali and other electrochemical cells, fuel cells and in other electrochemical applications.This three-layer laminate includes an active layer or sheet containing from about 60 to about 85 wt. % active carbon, the remainder being unsintered, fibrillated polytetrafluoroethylene in intimate admixture with said active carbon, said active layer laminated on its working surface to a current distributor and on its opposite surface to a porous, coherent, hydrophobic polytetrafluoroethylene-containing wetproofing layer.

Abstract: An electrode, especially for chlorine and hypochlorite production, comprises an electrocatalyst consisting of 22-55 mol % ruthenium oxide, 0.2-22 mol % palladium oxide and 44-77.8 mol % titanium oxide. The electrocatalyst may form a coating on a valve metal substrate and may be topcoated with a porous layer of titanium or tantalum oxide.