Abstract: Chlorate is removed from aqueous caustic soda by reducing with iron pentacarbonyl and separating off the resulting iron oxide containing precipitate.

Abstract: A multistage process for preparing pure BF.sub.3 from hexafluorosilicic acid, H.sub.2 SiF.sub.6, comprises reacting H.sub.2 SiF.sub.6 with oxygen acids of boron and/or boron oxide in the first stage to give hydroxyfluoroboric acid and silica, filtering off the silica and concentrating the hydroxyfluoroboric acid, adding oleum to the concentrate and then heating to form gaseous BF.sub.3.

Abstract: Cavities in mining are filled by introducing a mixture consisting of a slurry or sludge which evolves CO.sub.2, foams and solidifies and predominantly comprises alpha-hemihydrate, alpha-CaSO.sub.4. 0.5 H.sub.2 O, an alkali metal or alkaline earth metal carbonate and water, by a method in which the mixture is mixed with a bisulfate-containing aqueous solution or suspension of one or more metals before being introduced into the cavities to be filled.

Abstract: A multi-trace element fertilizer which contains magnesium as a further nutrient and in which the complex-forming trace elements are present in the form of anionic chelates with one or more N-carboxyalkylaminoacids is prepared by a process wherein the N-carboxyalkylaminoacids are reacted, in the presence of water, with the trace elements or trace element compounds in a molar ratio of N-carboxyalkylaminoacids to trace elements or trace element compounds of not less than 0.8:1, at least 20% by weight of the trace element compounds being oxides, hydroxides and/or carbonates. At the same time, or subsequently, the pH of the solution is brought to 3.5-6 by adding a member selected from the group consisting of magnesium oxide, hydroxide and carbonate. A maximum of 50 equivalent percent of the magnesium compound may however be replaced by a member selected from the group consisting of alkali metal oxides, hydroxides and carbonates and ammonia.

Abstract: The reaction off-gas from the synthesis of melamine consists, after separating off the melamine, mainly of ammonia and carbon dioxide, with traces of hydrogen cyanide, isocyanic acid, urea and residual melamine. To remove these trace components, the off-gas is passed over a catalyst, containing copper oxide and/or iron oxide, in the presence of steam at from 100.degree. to 500.degree. C.

Abstract: Storage-stable, pourable and pumpable silicate suspensions are prepared by wet milling of aluminosilicates, after the preparation of the latter, without intermediate drying.

Abstract: A storage-stable, pourable and pumpable aqueous suspension which contains finely divided water-insoluble sodium aluminum silicate and one or more hydroxyl-free saturated or unsaturated aliphatic dicarboxylic acids of 3 to 10 carbon atoms, or their alkali metal salts, as a stabilizer and flow improver.

Abstract: In a process for the manufacture of sodium dithionite by reacting sulfur dioxide with sodium formate and aqueous sodium hydroxide solution in the presence of methanol, an aqueous methanolic solution of sodium formate is first produced by reacting carbon monoxide with sodium hydroxide solution in an aqueous medium, containing from 1 to 50% by weight of methanol, based on the amount of water, at from 80 to 120.degree. C. under a pressure of from 10 to 40 bars. The resulting aqueous methanolic solution can be reacted directly, in the conventional manner, with sulfur dioxide and aqueous sodium hydroxide solution to give sodium dithionite.

Abstract: A process for welding membranes of fluorinated polymers which contain groups with exchangeable H-ions. To carry out the process, the polymer in at least one of the membranes to be welded together must be in the H-form.

Abstract: Concentrated dithionite solutions are produced by cathodic reduction of an aqueous solution, containing sulfite and/or bisulfite, which is circulated by pumping. The cathode and anode chambers are separated from one another by a permselective cation exchanger membrane. The catholyte must be circulated at least 10 times per hour and the selective catholyte volume outside the cell, defined asa = V.sub.total -V.sub.C /V.sub.total,Should be less than 0.9.

Abstract: Thermoplastic molding compositions comprise a linear nylon, an adduct of hexachlorocyclopentadiene and a dienophile as a flameproofing agent, zinc oxide as a synergistic agent, and reinforcing fillers. The zinc oxide is manufactured by adding an aqueous solution of a zinc salt and an aqueous solution of a base to an aqueous suspension of an inorganic carrier, the zinc oxide being precipitated at a pH of from 10 to 12. The molding compositions can be processed to give flameproof moldings having good mechanical properties.

Abstract: A process for the manufacture of acicular .gamma.-iron(III) oxide of improved crystallinity and high coercive force by heating goethite or acicular alpha-iron(III) oxide particles at temperatures of from 500.degree. to 800.degree. C, reduction of the resulting product at temperatures of from 280.degree. to 600.degree. C and subsequent oxidation of the magnetite to .gamma.-iron(III) oxide of improved crystallinity and high coercive force.

Abstract: Thermoplastic, linear, saturated polyesters containing flameproofing agents consisting of halogen compounds and an antimony trioxide which has been prepared in an aqueous suspension of an inorganic support using an aqueous antimony(III) halide solution and adding an aqueous solution of a base to raise the pH to from 6 to 8 with precipitation of the antimony compound onto the support, followed by separation of the solids from the aqueous phase.

Abstract: Sulfur concrete which exhibits improved compressive strength and flexural strength, and improved corrosion characteristics, is manufactured by mixing sulfur, dicyclopentadiene and aggregate at from 120.degree. to 160.degree. C. The period for which the sulfur and dicyclopentadiene interact should not exceed certain limits.