Abstract: This invention relates to a process of producing oxyacids of chlorine or salts of such acids by an electrolysis of salt solutions which are contaminated with calcium and/or magnesium or of sea water. In such processes, deposits or crusts are formed on the electrodes in the course of time, particularly in the cells to which the sea water is supplied first. For this reason, the plant must be cleaned from time to time. By means of the invention, a formation of crusts is virtually prevented in that the electrolysis is carried out(a) in an initial phase with an electrolyte flowing at a velocity above 0.7 meter per second and up to 2.0 meters per second and(b) in a succeeding phase with an electrolyte flowing at a velocity of 0.3 meter per second to less than 0.7 meter per second,the velocity of flow being stated for electrolyte which is free from gas.

Abstract: It is known to contact molten cast iron with various treating agents in the casting mold in order to influence the base structure or the form of the graphite. Such casting molds for making castings of cast iron containing vermicular and/or spheroidal graphite are provided with an intermediate chamber, which is provided in the pouring system between the pouring gate and the ingate to the casting mold proper. That intermediate chamber serves to receive the graphitizing agent and to contact it with the molten cast iron. To permit a functional adaptation of the chamber surface area or the surface area of the treating agent contained in the chamber to the pouring gate, which changes as the pouring proceeds, the casting mold is provided with a frustopyramidal intermediate chamber which has a rectangular base disposed in the parting plane of the mold.

Abstract: A process of purifying exhaust air which contains organic pollutants, particularly exhaust air from paint-drying operations, comprises adsorption on particulate activated carbon, which is contained in a fixed bed and from which at least part of the adsorbate can be desorbed. The activated carbon has a particle size in the range of about 2 to 6 mm, a bulk density of 250 to 450 g/l and B.E.T. surface area of 800 to 1800 m.sup.2 /g and the activated carbon is subjected to a desorbing treatment with steam while the bed of activated carbon is maintained at temperatures of 100.degree. to 150.degree. C.

Abstract: A piston for internal combustion engines, preferably made of aluminum or its alloys, having freely suspended piston pin bosses connected by first ribs to the piston head at points of zero moment and by second ribs to the piston skirt. The piston skirt has apertures in register with the bores in the piston pin bosses. The piston head is separated from the piston skirt by a transverse slot through at least a part of the circumference of the piston head and the ribs which connect the piston pin bosses to the piston skirt extend at an angle of 0.degree.-45.degree. to the boss plane.

Abstract: Residual materials which become available in metallurgy and contain oxides and volatilizable non-ferrous metals or compounds thereof are treated in a rotary kiln with solid carbonaceous reducing agents and are thus directly reduced in a high proportion to sponge iron whereas a substantial part of their non-ferrous metal content is volatilized. The solids discharged from the rotary kiln are sieved with a parting size of about 3 to 10 mm, depending on the feed grading of the residual materials and their disintegration characteristics, so that a major part of the unmagnetic material is included in the fine fraction. The coarse fraction is subjected to an electro-slag resistance process. The fine fraction is subjected to an electro-magnetic separation. The magnetic fraction is subjected to the resistance slag-refining process. The unmagnetic fraction is incorporated in and bonded to the feed mixture for the rotary kiln by a tumbling or pelletizing operation.

Abstract: A low-antimony lead alloy for use in the manufacture of paste-holding grids for lead-acid storage batteries contains 0.05 up to but less than 1.5 percent antimony. Such alloys represent an optimum combination of good processability, freedom from need for maintenance, low self-discharge rate and high cycle strength.

Abstract: Briquettes made of mainly coal are described to which there has been added 10 to 30% by weight of ash (other than ash which is contained in the coal normally). The briquettes formed from such a mixture have strength which permits them to be subjected to gasification or carbonization in a fixed bed. Also described is a method for forming the briquettes.

Abstract: An improved process for briquetting sponge iron-containing material wherein as binder there is employed dilute sulfuric acid and the sponge iron-containing material contains at least 40% by weight metallic iron.

Abstract: The invention provides a process for thermally decomposing salts, containing mainly ferrous sulfate wherein said feed material is contacted in a single suspension-type exchanger with exhaust gases formed by reaction of the oxygen-containing gases in the fluidized bed reactor, the fluidizing gas and at least a partial stream of the secondary gas stream are heated by an indirect heat exchange in a fuel-heated heat exchanger, and the quantity of oxygen introduced via which consists of the fluidizing gas and the secondary gas, is controlled in dependence on the quantity of fuel in order to receive an exhaust gas from the suspension-type exchanger with a free oxygen content of 1-6% by volume and a temperature of 300.degree.-450.degree. C.

Abstract: In a process of selectively desulfurizing gases which contain hydrogen sulfide and carbon dioxide comprising scrubbing the gases with an aqueous potassium carbonate solution under superatmospheric pressure and at temperatures of about 100.degree. C., regenerating the laden scrubbing solution and recycling the regenerated scrubbing solution, the improvement wherein the gases to be purified are scrubbed with an aqueous potassium carbonate solution so as to maintain a mass ratio of 1.0 to 3.0 vals (gram equivalents) of alkali in the solution per mole of CO.sub.2 and H.sub.2 S in the gases to be purified, the laden scrubbing liquor is subsequently regenerated by being stripped with a gas in which a CO.sub.2 partial pressure above 0.2 bar is maintained, and the so regenerated scrubbing solution is recycled.

Abstract: Zinc and, if desired, lead are volatilized from a metallurgical material such as a finely divided oxidic ore, ore concentrate or another metallurgical intermediate. The volatilization of the zinc is carried out at a temperature above 1300.degree. C. in a cyclone chamber which has an axis that is substantially horizontal, i.e. is inclined to the horizontal at an angle of 0.degree. to 15.degree.. Carbon dioxide is removed from the gas leaving the zinc condensing stage and the high carbon monoxide gas thus obtained is recycled to the cyclone chamber or at another point ahead of the condensation stage.

Abstract: An electrostatic precipitator for the removal of dust from a gas stream entraining same is subdivided into a plurality of flow passages which can be selectively or collectively shut off. When one of these flow passages is closed off, the collecting electrodes can be rapped, after the high voltage has been disconnected, to cause the collecting electrodes to shed their dust. A conductivity-promoting substance in liquid or powder form is then sprayed into the closed-off flow compartment to deposit upon the collecting electrodes thereof and simultaneously the electrodes are energized. Thereafter, the flow of the gas stream entraining the gas through the flow passages is recommenced and electrostatic deposition of dust takes place in the usual manner. The system has been found to be highly effective for the collection of high-resistance dusts and to avoid reverse ionization effects.

Abstract: Process for the production of polyurethanes dissolved in a solvent by mixing linear pre-adducts having terminal NCO groups dissolved in solvents with hydrazines and/or dihydrazine compounds and or diamines dissolved in solvents, for the purpose of forming partially cross-linked polyurethanes, whilst continuously measuring the viscosity until the viscosity shows a value which is located in the shaded zone of the section of curves shown in FIG. 1, the addition of the pre-adduct solution being carried out at such a speed that the final solution has solids content of between 25 and 35 per cent by weight, and coagulation of the obtained solution to fabricated shapes, especially to microporous sheet structures.