Abstract: In a process for producing granular material in which at least one hard material phase is mixed with a metal powder and a binder and granulated, no premixing of the hard material phase and the metal powder takes place before mixing with the binder and the binder has a viscosity of from 20 to 200 cm.sup.3 /10 min, preferably from 30 to 100 cm.sup.3 /10 min, in accordance with DIN 53735 at 195.degree. C. and a load of 2.16 kg.

Abstract: Preforms are produced from ceramic and/or metallic fibers by injection molding or extruding a mixture containing the fibers and a thermoplastic binder, said thermoplastic binder being polyoxymethylene, which after the shaping is removed by treatment in a gaseous acid-containing atmosphere or in a gaseous BF.sub.3 -containing atmosphere.

Abstract: A gas-evolving metal electrode consists of profiles which are arranged parallel to one another in a horizontal plane and are connected to one another by means of current distributors. The profile surfaces which face the counter-electrode are curved, the curvature at the sides being more pronounced than that in the middle. The profile is terminated above by means of two lateral surfaces tangential to the curvature. The electrode is useful as an anode for mercury cells for the chloralkali electrolysis.

Abstract: Yellow pigments containing bismuth vanadate and having the compositionBiVO.sub.4.xBi.sub.2 MoO.sub.6.yBi.sub.2 WO.sub.6where x is from 0.6 to 2.25 and y is from 0 to 0.1, are prepared by a process in which a solution containing a bismuth(III) salt, a vanadate and a molybdate is acidified until the pH is <0, the pH of the acidic solution is then brought to 0.1-3.5, at from 20.degree. to 95.degree. C., by means of an alkaline solution which may or may not contain a dissolved tungsten(VI) compound, the precipitated product and the reaction solution are left at from 50.degree. to 100.degree. C. for from 30 to 120 minutes and then separated from one another, and the product is washed, dried if required and heated at from 300.degree. to 800.degree. C.

Abstract: Bipolar electrodes with graphite as the carrier have a layer of chromium trioxide not less than 10 .mu.m thick on both the anode face and the cathode face.The electrodes are produced by plasma-spraying chromium trioxide powder onto a graphite layer, and can be used as bipolar electrodes in alkali metal chloride electrolysis cells.

Abstract: In an electrode suitable for electrolysis of aqueous sodium chloride or potassium chloride solutions, at least the outer layer contains spinels, specifically a mixture of the individual spinels of iron and of cobalt, the weight ratio of iron spinels: cobalt spinels being from 30:70 to 90:10.The electrodes are produced by applying a powder mixture of iron spinel and cobalt spinel to a substrate by a plasma spraying process wherein argon is used as the plasma gas and the spraying energy is from 6 to 30 kW.

Abstract: Flaky mica pigments coated with metal oxides are prepared by oxidizing vaporizable metal carbonyls to metal oxides with oxygen at an elevated temperature in the presence of mica flakes which are kept in motion. The amount of carbonyls introduced into the reaction zone does not exceed 5% by volume of the amount of other gases introduced.The coated mica pigments are employed as pigments in surface coatings, plastics and glasses.

Abstract: To prepare a colored pigment which has a metallic luster and consists of a metallic core whose surface is at least partially covered with an iron oxide, iron pentacarbonyl is oxidized with oxygen in a fluidized bed of the metallic cores at above 100.degree. C. The amount of iron pentacarbonyl vapor introduced into the fluidized bed must not exceed 5% by volume, based on the total gases introduced into the fluidized bed over the same period of time.

Abstract: A process for the recovery of methylglyoxal acetal from a reaction mixture which has been obtained in the reaction of acetone with an alcohol and a nitrosation agent or oxidizing agent in the presence of an acid catalyst followed by neutralization which comprises diluting the neutralized reaction mixture with such an amount of water that a homogeneous solution is formed, subsequent distillation in a first column in which a mixture of acetone, alcohol and solvent is removed overhead and returned direct to the synthesis and an azeotrope of methylglyoxal acetal, water and high-boilers is withdrawn as a side stream, condensation of the azeotrope thus obtained and separation of the phase rich in methylglyoxal acetal, subsequent distillation of the phase rich in methylglyoxal acetal thus obtained in a second column in which purified methylglyoxal acetal is withdrawn as a side stream and the overhead and bottoms products are returned with the feed to the first column, pure methylglyoxal acetal being obtained as the