Abstract: In electrolytic cells for producing aluminum in a side-by-side arrangement, a number of cathode bus bars connected to cathode current collector bars projected from upstream long side of each electrolytic cell are connected to at least one rising bus bars provided at upstream long side of an adjacent electrolytic cell provided on downstream side through at least one cathode bus bars provided in the space below the relevant cell and in parallel to the axial line of a row of electrolytic cells; the remaining number thereof are connected to rising bus bars provided at short ends of the adjacent electrolytic cell on the downstream side through cathode bus bars extending along outsides at the short ends of the relevant electrolytic cell, a number of cathode bus bars connected to cathode current collector bars projected from downstream long side of each electrolytic cell are connected to at least one rising bus bar provided on upstream long side of the adjacent electrolytic cell on the downstream side, and the remai

Abstract: A plurality of rectangular electrolytic cells are disposed in at least two rows of a side-by-side arrangement of cells. A first set of cathode bus bars extends along the outside of the short end of the cell facing the other row of cells. This set of bus bars, along with a second set of bus bars disposed beneath the cell, collect cathode current from the upstream long side of the cell. The second bus bars are positioned, and current through each set of bus bars is controlled, to minimize disruption of the molten bath due to circulation flow.

Abstract: A highly efficient process for producing metallic gallium from a gallium containing alkali aluminate solution circulating in the Bayer process is disclosed. The process comprises subjecting an alkali aluminate solution to electrolysis, said solution being obtained by (1) cooling an alkali aluminate solution after the aluminum hydroxide separation step in the Bayer process in the presence or absence of at least one, as a seed, alkali salt of an element selected from vanadium and phosphorus, or complexes containing the alkali salt, in order to precipitate crystals of impurities containing vanadium, phosphorus, etc.

Abstract: Coarse grains of aluminum hydroxide having high resistance to disintegration to powder in a calcination step are continuously produced from a supersaturated sodium aluminate solution of the Bayer process through(1) a first precipitation step of adding recycle seed aluminum hydroxide to a supersaturated sodium aluminate solution having a molar ratio of Na.sub.2 O as caustic soda to Al.sub.2 O.sub.3 in solution of less than 1.8 supplied to a precipitation tank of substantially complete mixing type in a ratio of 30-150 kg of the recycle seed to 1 m.sup.3 of the solution, thereby partially decomposing the seed-added solution until the molar ratio of the solution reaches 2.0-2.4 while keeping the solution at 65.degree.-80.degree. C.

Abstract: Coarse grains of aluminum hydroxide are economically produced in a high yield from sodium aluminate solution by dividing supersaturated sodium aluminate solution being prepared by the Bayer process and having a molar ratio of Na.sub.2 O as caustic soda to Al.sub.2 O.sub.3 in solution of less than 1.8 into two streams, adding a portion of recycle seed aluminum hydroxide and fine grains of aluminum hydroxide as seed to one of the streams of sodium aluminate solution, partially decomposing the sodium aluminate solution until the molar ratio of the sodium solution reaches 1.8-2.6, adding to the resulting partially decomposed sodium aluminate slurry the other stream of sodium aluminate solution, which has been cooled to a temperature low enough to lower the temperature of the partially decomposed sodium aluminate slurry by at least 3.degree. C.

Abstract: In lining parts to be stamped of an aluminum electrolytic cell by filling a carbonaceous stamping material into the part and stamping the filled stamping material, a mixture consisting essentially of a carbon aggregate and a binder and being capable of being stamped at a temperature above 100.degree. C. is prepared; a solvent for the binder containing aromatic hydrocarbon as a main component in an amount insufficient to effect stamping of the stamping material at room temperature, but sufficient to stamped at a temperature of 50.degree. to 100.degree. C., when added to the mixture; the mixture and the solvent are mixed together, before application, to prepare a carbonaceous stamping material; and the carbonaceous stamping material is applied to the part of the cell to be stamped at a temperature of 50.degree. to 100.degree. C.

Abstract: Impurities such as organic substances, i.e. sodium oxalate and inorganic impurities, i.e.

Abstract: A hollow catalyst carrier and hollow catalyst made of a transition-alumina (e.g. .gamma.-alumina) which comprises a calcined product having a pipe-like or multi-cell structure and having a very large void ratio (i.e. not less than 3%), a very large specific surface area (i.e. not less than 5 m.sup.2 /g), a bulk density of 0.8 to 1.8 g/cm.sup.3, a compressive strength in the extrusion direction of not less than 20 kg/cm.sup.2 and at least one hole in the extrusion direction, and a process for the production thereof by subjecting a powder containing a rehydratable alumina to an extrusion molding, rehydrating the molded product and followed by calcining. The hollow catalyst carrier and hollow catalyst have excellent properties for carrying the catalytically active components thereon and have an excellent mechanical strength.

Abstract: A process for the removal of sulfur oxides from exhaust gases by absorbing with a slurry of red mud containing calcium ion which comprises the steps of:(1) contacting an exhaust gas containing sulfur oxides of not higher than about 100.degree. C. with a slurry of red mud containing calcium ion led from the next step (2) to take up sulfur oxides in the gas until pH of the slurry becomes in the range of 4.3 to less than 6 while maintaining the molar fraction of SO.sub.4.sup.-- to total SO.sub.2 in the slurry within the said pH range at 0.05 to 0.7; and then,(2) contacting the treated gas with a fresh slurry of red mud containing calcium ion to further take up sulfur oxides in the gas while maintaining the concentration of NaHSO.sub.3 in the slurry at not more than about 8 g/l.

Abstract: A process for producing alumina sols characterized by neutralizing a water-soluble basic aluminium salt of the formula,Al.sub.2 (OH).sub.x X.sub.y Y.sub.zwherein X is Cl or NO.sub.3, Y is SO.sub.4, and x, y and z are numbers satisfying the equations, x+y+2z=6, 0<x<6, 0.ltoreq.y<6, 0.ltoreq.2z<6, provided that y and z are not zero at the same time, with an alkali to produce alumina gels, and the subjecting said alumina gels to a hydrothermal treatment in the presence of a monovalent organic acid of such an amount that the molar ratio of the organic acid to aluminium is from 0.001 to 0.15.The alumina sols of the present invention are low in viscosity, high in Al.sub.2 O.sub.3 content and are extremely superior in stability with the lapse of time, and produce alumina powders superior in re-dispersibility.