Abstract: To prepare C.sub.1 -C.sub.4 -dialkyl carbonates, C.sub.1 -C.sub.4 -alkanols are reacted with CO and O.sub.2 at a relatively high temperature in a salt melt containing Cu salts.

Abstract: A flotation process for the continuous recovery of silver or silver compounds from solutions or dispersions is described, wherein finely divided, inert gas bubbles are injected into the dispersions of silver and silver compounds in the presence of protein and the pH of the medium is maintained at the isoelectric point of the protein. Addition of a surface active agent accelerates the process. The desilverized effluent has a silver content of less than 1 mg of Ag/l. The quantity of flotate (12) is less than 2% of the quantity of effluent (5) put into the process.

Abstract: The present invention relates to an apparatus for flotation, wherein the mixture to be subjected to flotation is mixed with gas, preferably air, inside a flotation cell, in funnel-shaped nozzles in which a conical deflector is arranged in line with the axis of the propulsion jet.

Abstract: The present invention relates to a mechanical foam breaker containing a tube (1), and at least 3 channels (2) which branch outwards radially from the suction tube (1) at an angle .alpha. of approx. 30.degree. to approx. 60.degree..

Abstract: An improved process for the production of cyanogen chloride is disclosed according to which liquid hydrocyanic acid and gaseous chlorine are reacted in an aqueous medium. The liquid hydrocyanic acid and chlorine are introduced into a column-shaped reactor via at least one two-component nozzle. The reaction mixture is removed at the head of the column-shaped reactor. Preferably, the hydrocyanic acid is in liquid form and the chlorine is in gaseous form. By the process disclosed, quantitative yields of cyanogen chloride are obtained separately from aqueous solutions of hydrochloric acid of a strength suitable for commercial use.

Abstract: A process and apparatus for the continuous introduction of air or oxygen-containing gases into an effluent containing activated sludge, the oxygen-containing gas largely being consumed by the effluent containing activated sludge in a single absorption stage, comprising introducing through a plurality of gas inlets an oxygen-containing gas into an effluent containing activated sludge which is in a basin under its own hydrostatic pressure of at least about 0.9 bar, the gas pressure of the gas introduced being about 0.01 to 0.5 bar above the hydrostatic pressure prevailing at the gas inlet, each gas inlet having a gas-swept cross-sectional area of at least about 0.01 m.sup.2 which is loaded by at least about 100 effective cubic meters of gas per square meter of cross-sectional area per hour, and the individual gas inlets being separated by a distance of at least about 0.5 meter, as measured from the middle point of a gas inlet.

Abstract: In an injector for the dispersion of a gas into a liquid and comprising a gas inlet, a liquid inlet, and a mixing chamber communicating with said inlets and having an inlet and an outlet, the improvement which comprises at least one deflecting element disposed in the mixing chamber along the axis of the liquid inlet, whereby the liquid is distributed across the full cross-section of the mixing chamber. The deflector may be flat, conical or parabolic or it may be axially offset relative to the mixing chamber as a tongue. Special configurations are shown which are especially suited for use in treating liquid effluents and in fermentation processes.

Abstract: In an injector for the dispersion of a gas into a liquid and comprising a gas inlet, a liquid inlet, and a mixing chamber communicating with said inlets and having an inlet and an outlet, the improvement wherein the inlet of said mixing chamber is substantially round in cross-section and the outlet is substantially slit-shaped, whereby the kinetic energy of propulsion can be utilized with high efficiency to produce very fine gas bubbles. Advantageously the cross-sectional area at the outlet of the mixing chamber is about 5 to 25 times the cross-sectional area of the liquid nozzle throat, the liquid nozzle has a throat diameter d diverging to its discharge at an angle of about 5.degree. to 10.degree., the mixing chamber beginning at a distance from about 1 to 3 d from the end of the inlet, the inlet of the mixing chamber being circular of a diameter of about 3 d, the mixing chamber having a length of about 5 d to 20 d, and the height of the slit being about 1 d.

Abstract: Aminonaphthalene derivatives are prepared by reacting the corresponding naphthol derivative with ammonia or amines in the presence of bisulfites. The reaction is carried out in a continuous procedure in reaction apparatus which consists wholly or partly of titanium or a titanium alloy, carbon largely excluded. Suitable alloys are titanium/palladium, titanium/nickel or titanium/molybdenum.