Abstract: Process for the preparation of pure propanephosphonic anhydride, which comprises distilling crude, impure propanephosphonic anhydride having an average degree of polymerization of 20 to 200 and containing less than 0.5% by weight of water by heating to 230 to 300.degree. C. under a pressure of 0.1 to 100 mbar, pure propanephosphonic anhydride having an average degree of polymerization of 20 to 60 being obtained.

Abstract: In a method of disposing of organic and inorganic substances, the substances are gasified and decomposed in and/or above a liquid bath of a metal alloy under negative pressure, off-gases forming are seized, collected and purified and separated.To prevent the formation of health-endangering emissions, such as dioxins and furans, and to recover pure starting materials for the production of organic substances, the substances are charged under negative pressure into an induction furnace containing a melt (18) of an iron alloy, in particular a steel melt, and are decomposed in the latter at liquid steel temperature, whereby the entry of gaseous O.sub.2 is avoided.This is also the case at the production of steel from scrap interspersed with organic substances.

Abstract: The invention relates to an improved process for the preparation of a compound of the formula R.sup.1 -X-SO.sub.2 -NCO in whichX is O or NR.sup.2,R.sup.1 is alkylsulfonyl or phenyl which is optionally substituted by Hal, alkyl and/or alkoxy, andR.sup.2 is alkyl, by reactingR.sup.1 XH with ClSO.sub.2 NCO to give the compound R.sup.1 XCONHSO.sub.2 Cl followed by a rearrangement reaction, which comprises carrying out the process continuously in the presence or absence of an inert solvent.

Abstract: The invention relates to a process for the preparation of vinylphosphonic dichloride through elimination of hydrogen chloride from 2-chloroethanephosphonic dichloride in the presence of catalysts. The catalysts used are tertiary phosphines, quaternary ammonium or phosphonium salts or alkali metal or alkaline-earth metal halides. When triphenyl phosphine is used as the catalyst, the reaction is carried out under reduced pressure at a temperature of 130.degree. to 166.degree. C. and the vinylphosphonic dichloride produced is simultaneously removed by distillation under reduced pressure. When the other catalysts are used, the process can be carried out at atmospheric pressure or reduced pressure and at temperatures of about 130.degree. to 220.degree. C. and the vinylphosphonic dichloride produced can be removed by distillation simultaneously with or subsequent to the reaction.

Abstract: The invention relates to a process for the preparation of vinylphosphonic dichloride, in which a 2-chloroethanephosphonate of the formula ##STR1## or a mixture of the two esters, is reacted with thionyl chloride at a temperature of 60.degree. to 160.degree. C. in the presence of a catalyst which contains tertiary phosphines, quaternary ammonium or phosphonium salts or alkali metal or alkaline-earth metal halides.During this reaction, any thionyl chloride which may be present is removed by distillation subsequent to this reaction, the mixture remaining is heated to 140.degree. to 200.degree. C., and the vinylphosphonic dichloride produced during this is removed by distillation.

Abstract: The invention relates to a process for the preparation of 2-chloroethanephosphonic dichloride through reaction of a 2-chloroethanephosphonate of the formula ##STR1## or a mixture of the two esters, with thionyl chloride at a temperature of 60.degree. to 160.degree. C. In this reaction, tertiary phosphines, quaternary ammonium or phosphonium salts or alkali metal or alkaline-earth metal halides are employed as catalysts. The thionyl chloride is introduced into the initially introduced ester.

Abstract: A plant for the production of steel from scrap and optionally fluxes includes a shaft furnace section having a bottom to receive a liquid sump of premelt and heating means laterally entering into the lower part of its interior. A hearth type furnace section is integrally connected with the shaft furnace section, into which the premelt is transferable from the shaft furnace section.

Abstract: A process and an arrangement for the production of steel from sponge iron. In order to be able to process sponge iron with high contents of acid gangue and a phosphorus content of more than 3% in an economic and operationally safe manner, the following measures are taken:melting the sponge iron charge, if desired, together with scrap, in an acid-lined electric furnace,tapping the steel melt slag-free into a basic-lined ladle by introducing a particulate dephosphorizing agent into the casting jet,removing the phosphorus-containing slag formed from the ladle and subsequently introducing the ladle into a ladle heating stand, in which additional dephosphorizing agent is blown into the melt together with oxygen or oxygen-containing gas, which treatment, if necessary, is repeated after extraction of the formed slag, with the ladle content optionally being heated to adjust the desired dephosphorization temperature of about 1,550.degree. to 1,600.degree. C.

Abstract: A hoist comprises a housing carrying a fixed and slidable sheave set which are engaged by a rope. A piston and cylinder combination are connected to the slidable sheave set for moving it and thus moving a load connected to the rope. The piston has a threaded rod connected to the displaceable sheave set which carries a threaded nut. The axial movement of the nut is restrained by a sleeve which permits rotation of the nut with axial movement of the rod. If the axial movement of the rod accelerates above a selected limit, for example when the load is abruptly removed from the rope, the nut moves against a friction surface in the sleeve to brake the rotation thereof and thus brake the axial movement of the rod.

Abstract: An absorbent for water purification consisting of organic polymers and inorganic absorbing matter having a large surface is obtained by epitactically linking with each other the two components. The absorbent has good absorbing properties with respect to different classes of substances.

Abstract: Drinking water is prepared from crude water containing dissolved lypophilic contaminants by adding polymers of ethylene or substituted ethylenes or copolymers of ethylene with less than 50 % by weight of other ethylenically unsaturated monomers which may contain additionally less than 2 mole % of ethylenes carrying a carboxyl function, and separating the polymer substance containing the lipophilic contaminants.

Abstract: Apparatus is disclosed for feeding ringing currents from a ringing current supply to line circuits, and for controlling ringing currents in such line circuits, in telephone and other telecommunication systems having an exchange equipped with a source of supply voltage and having subscriber circuits equipped with a ringing circuit capacitor. The disclosed invention comprises a combination of a junction for feeding ringing currents to line circuits, a diode connected between the feeding junction and a pole of the source of supply voltage, an electronic switching device having a control electrode and being connected between the ringing current supply and the feeding junction, and equipment connected to the control electrode of the switching device for causing the switching device to switch ringing currents on and off instantly and to discharge the ringing circuit capacitor.