Abstract: The invention is in a composition and process for the chromium free passivating postrinsing of conversion layers on metals before the application of a paint or adhesive. The conversion layers can be on the bases of phosphate layers, at least two polyvalent metal ions with complex formers, titanium, zirconium and/or hafnium. The postrinsing agent is an aqueous solution which has been adjusted to a pH value of up to 5 and which contains an aluminum fluorozirconate having an Al:Zr:F mole ratio of (0.15 to 8.0):1:(5 to 52), and in which solutions the total concentration of Al+Zr+F is 0.1 to 8.0 g/l. The postrinsing solutions may additionally contain at least one of the anions benzoate, caprylate, ethyl hexoate, salicylate in a total concentration of 0.05 to 0.5 g/1 and may preferably be adjusted to the required pH value with cations of volatile bases, such as ammonium, ethanolammonium and di- and triethanolammonium.

Abstract: A fibrous electrically-conductive filler comprises fibrous aluminum borate as a core material and a layer of a electrically-conductive substance which covers the core material or comprises fibrous aluminum borate as a core material, a layer of titanium oxide which covers the fibrous aluminum borate and a layer of a electrically-conductive substance which covers the titanium oxide layer. The fibrous electrically-conductive filler can be prepared by a process comprising the step of directly forming a layer of a electrically-conductive substance doped with antimony or fluorine on the surface of fibrous aluminum borate, or the steps of forming, on the surface of the fibrous aluminum borate, an intermediate layer of titanium oxide in an amount ranging from 2 to 50% by weight on the basis of the weight of the fibrous aluminum borate and then forming a layer of a electrically-conductive substance doped with antimony or fluorine on the surface of fibrous aluminum borate.

Abstract: The gas to be treated contains H.sub.2 S and carbon compounds first enters the combustion chamber of a Claus process plant and a gas mixture which contains 1 to 3 moles H.sub.2 S per mole of SO.sub.2 is withdrawn from that combustion chamber. The gas mixture is reacted in part to form elemental sulfur in at least one catalytic Claus process stage at temperatures above the dew-point temperature of the sulfur. The elemental sulfur is condensed in and removed from a sulfur cooler. An exhaust gas which contains 0.5 to 5% by volume H.sub.2 S and also contains COS, CS.sub.2 and H.sub.2 O is withdrawn from the last sulfur cooler of the Claus process plant. Oxygen is admixed with that exhaust gas, which is heated to a temperature of at least 200.degree. C. and is contacted with a catalyst, which comprises at least 80% by weight TiO.sub.2. The resulting elemental sulfur is condensed and withdrawn. The gas is subsequently contacted at temperatures of 120.degree. to 160.degree. C.

Abstract: To a gas which contains H.sub.2 S and water vapor and which is to be desulfurized oxygen is added at such a rate that the gas contains 1 to 20 moles O.sub.2 per mole of H.sub.2 S. At a temperature in the range of 50.degree. to 180.degree. C. the gas is contacted with activated carbon, which is thus laden with elemental sulfur and with at least 3% by weight sulfuric acid. In a suitable processing, the gas which is to be desulfurized and contains at least 1000 ppm H.sub.2 S+SO.sub.2 is initially passed at a temperature from 100.degree. to 180.degree. C. through a catalytic prepurifier, in which elemental sulfur is adsorbed on a high-metal-oxide catalyst, oxygen is admixed to the gas coming from the prepurifier and the gas at a temperature of 50.degree. to 180.degree. is contacted with the activated carbon for a final desulfurization.

Abstract: A process and apparatus for the qualitative analysis of particles of various kinds of plastic which comprises passing said particles serially in a predetermined path, irradiating each particle with light of short wavelength from 180 to 500 nm, whereby each particle emits light radiation of a longer wavelength, and detecting such longer wavelength emissions for radiation intensities within a narrow wavelength range to form an emission spectrum, the emission spectrum generating a sorting signal.

Abstract: In a process of manufacturing a channel plate assembly including a plurality of partial plates confining passages for a first medium which continuously define on all sides in direction of flow and interconnected by a plurality of spacers spaced apart in the direction of flow, the spacers are fixed in a fixture and joined to a first plate, and then the spacers are joined to another plate in a fixture on a side which faces away from the first plate.

Abstract: In the reduction of liquid slags or molten salts which contain nonferrous metal oxides and are disposed over a liquid metal layer consisting of the corresponding nonferrous metal oxides and are disposed over a liquid metal layer consisting of the corresponding nonferrous metal, carbonaceous reducing agents and oxygen-containing gas are injected through nozzles into the metal layer. In order to improve the gasification of the reducing agent the height of the metal layer is so selected that at least 50% of the reducing agent are reacted to CO and optionally H.sub.2 in the metal layer before the reducing agent enters the slag layer.

Abstract: The acid scrubbing liquid which has a pH value below 3 and is used in a scrubbing zone to remove acid components from a gas. At least part of the scrubbing liquid is circulated. A partial stream of the scrubbing liquid at a constant rate is mixed with an alkaline solution stream which has a constant concentration and is supplied at a constant volume rate, the pH value of the resulting mixture is continually measured, a setpoint in the range from 5 to 9 is selected for the pH value of the mixture, and a neutral or alkaline correcting liquid is added to the scrubbing liquid in response to a decrease of the measured pH value below said setpoint. The scrubbing liquid may mainly consist of water.

Abstract: A waste pickle which has been formed in the surface treatment of rolled stock consisting of steel and contains metal salts and acids and specifically contains nitric and hydrofluoric acids and nickel salts, chromium salts, and iron salts is subjected to an acid dialysis and a membrane electrolysis. To permit a recycling of free acids at a high rate and a recovering of the metals in a form in which they can directly be used in the melting process, the acid dialysis performed for a recovery of the free nitric acid and hydrofluoric acids is succeeded by a membrane electrolysis, in which the metals are recovered from the depleted effluent from the acid dialysis, which effluent has been depleted of free acid, and the enriched effluent from the acid dialysis, which enriched effluent has been enriched with free acids, and the effluent from the membrane electrolysis, which effluent has been depleted of metals, are subjected to an evaporation.

Abstract: Disclosed is a composition and a process of using the composition for phosphating a workpiece made of steel or partly galvanized steel in preparation for electro-immersion painting. The cleaned and rinsed workpiece is first activated with a weakly alkaline aqueous solution which contains titanium phosphate and is subsequently dipped into an acid aqueous phosphating solution at a temperature of from 40.degree. to 60.degree. C. which contains1.8 to 5 g/l Zn,0.1 to 7 g/l Fe(II),8 to 25 g/l P.sub.2 O.sub.5,5 to 30 g/l NO.sub.3and in which the controlled ratio of free acid to total acid is between 0.04 and 0.07.The phosphating solution preferably contains 3 g/l zinc and 0.5 to 5 g/l iron(II) and additionally contains up to 3 g/l manganese.Other suitable components of the phosphating solution are Co, Ni, hydroxylamine, fluorides, tartaric acid, citric acid, and m-nitrobenzene sulfonate.

Abstract: The process of concentrating a dilute sulfuric acid in a three-stage vacuum evaporation plant includes feeding an entry dilute sulfuric acid to a first evaporation stage of a vacuum evaporation plant to form an overhead vapor (6), withdrawing a finally concentrated sulfuric acid from the third evaporation stage (3), using steam or the overhead vapor (6) of the first evaporation stage as a heating fluid in the three-stage vacuum evaporation plant, maintaining the entry dilute sulfuric acid under a pressure of 0.4 to 0.7 bar and at a temperature of 80.degree. to 120.degree. C. in the first evaporation stage (1), maintaining the partially concentrated sulfuric acid under a pressure of 0.02 to 0.06 bar and at a temperature of 50.degree. to 90.degree. C. in the second evaporation stage (2), maintaining the further concentrated sulfuric acid under a pressure of 0.02 to 0.06 bar and at a temperature of 80.degree. to 120.degree. C.

Abstract: Contaminated soils are treated in that an aqueous slurry of the soil is separated into a coarse fraction and a fine fraction, the fine fraction is subjected to flotation, the resulting froth is dewatered and then carried away as a pollutant concentrate, and the underflow from the flotation is dewatered and is then carried away as purified soil. An emulsified oily vegetable oil is used as a collector agent for the selective flotation or an emulsified light mineral oil is used as a collector agent for the selective flotation and a light mineral oil is stirred as a conditioning agent into the fine fraction before it is subjected to the selective flotation.

Abstract: The process of removing dust, sulfur compounds and nitrogen oxides from combustion exhaust gases, comprising mixing a combustion exhaust gas with ammonia; feeding Ca(OH).sub.2 and FeSO.sub.4 to a fluidized bed reactor containing mixed solids including fly ash, iron sulfates and calcium compounds, especially Ca(OH).sub.2, CaCO.sub.3, CaO, CaSO.sub.4 and CaSO.sub.3 ; supplying an ammonia-containing exhaust gas mixture to the fluidized bed reactor as a fluidizing gas; operating the fluidized bed reactor at a temperature between 300.degree. and 450.degree. C. to form a reacted exhaust gas; supplying the reacted exhaust gas to a multistage electrostatic precipitator having a first stage and additional stages; recycling solids collected in the first stage to the fluidized bed reactor; and recycling one portion of additional solids collected in the additional stages to the fluidized bed reactor and discharging another portion of the additional solids.

Abstract: A reactor for combusting fine-grained solid fuels in a circulating fluidized bed contains a combustion chamber, which is provided with lines which open in the lower portion of that chamber and serve to feed primary air, secondary air and solid fuel. The fluidized bed combustion chamber is divided into compartments by at least one partition provided in the upper portion of the fluidized bed combustion chamber. Each compartment communicates through a passage with at least one solids separator, which is connected to means for recycling solids and communicates with the compartment through a passage.

Abstract: A filter vessel comprises a sieve or nozzle bottom, which carries a filter material and on which at least one trough for washing out the filter material is provided. A pipe for rinsing liquid is disposed above the trough and is provided with a plurality of nozzles, which are obliquely directed into the trough. The distance A measured between the top edges of the trough and the longitudinal axis of the pipe is 0.2 to 2 times the outside diameter D of the pipe.

Abstract: The seal is provided at a joint between two ducts, which are traversed by hot gases. It has a seat for the seal and an elastic compensator strip, which spans the gap between the two ducts. A woven wire cloth is provided under the compensator strip. A metal foil is provided over the woven wire cloth and a packing of ceramic fibers is provided over the metal foil. A seat member for the seal is joined to each of the two ducts. Each seat member is provided with a row of pointed rods of metal, which extend through the woven wire cloth, the metal foil and the packing of ceramic fibers.

Abstract: A process for forming phosphate coatings on metal surfaces is provided which comprises the steps of contacting said metal surface with an Fe(II)-containing phosphating solution comprising0.4 to 30 g/l Zn4 to 30 g/l P.sub.2 O.sub.55 to 50 g/l NO.sub.3up to 10 g/l Fe(II) ; andup to 0.3 g/l (Fe(III)wherein the weight ratio of free P.sub.2 O.sub.5 to total P.sub.2 O.sub.5 is (0.04 to 0.50):1 and, replenishing said phosphating solution with Zn, NO.sub.3 and P.sub.2 O.sub.5 in a weight ratio ofZn:NO.sub. 3 P.sub.2 O.sub.5 =(0.60 to 0.30):(0.2 to 0.4):1.wherein the Fe(II) content is adjusted by oxidation with nitrate or nitrite derived from nitrate optionally employed with an oxygen-containing gas, H.sub.2 O.sub.

Abstract: Disclosed is a process of removing zinc from a phosphating process sludge wherein the phosphating process sludge is mixed with an additive adapted to form slaglike compounds of iron, calcium and/or barium with the phosphorus component of the phosphating process sludges. The mixture is reacted at temperatures of at least 800.degree. C. under reducing conditions. A previous agglomeration, particularly pelletizing, of the mixture will be of advantage. For a formation of iron compounds it will be particularly desirable to employ reaction temperatures of at least 900.degree. C., preferably of at least 1000.degree. C. and most preferably of at least 1100.degree. C. Metallurgical dusts are particularly suitable additives. For a formation of iron compounds it will be desirable to select a Fe:P molar ratio of at least 1.0 in case of a reaction temperature of .ltoreq.950.degree. C., of at least 1.5 in case of a reaction temperature of 950.degree. to 1050.degree. C., and of at least 2.

Abstract: A filter element is disclosed which serves to separate dusts from gases or air and consists of metals, alloys or plastics. The element is thin-walled and sheetlike, has a wall thickness of 0.05 to 2 mm and has a large number of regularly arranged holes, which have any of various shapes and sizes and have a non-circular cross-section and a hydraulic diameter of 0.01 to 1 mm. In that filter element the area which is occupied by the holes is 3 to 25% of the front surface area of the filter element.

Abstract: In a process of producing strip or wire, which consists of a monotectic aluminum-silicon alloy comprising a matrix consisting of aluminum and an aluminum-silicon eutectic system and as a minority phase 1 to 50% by weight lead or bismuth included in said matrix, which strip or wire has been continuously cast at a high casting velocity and a high cooling rate from a molten material which has been heated to a temperature above the segregation temperature, and which strip or wire has been subjected to plastic deformation and to a heat treatment, the minority phase which is embedded in the form of elongate platelets in the strip or wire is transformed to more compact shapes by a heat treatment at temperatures of 550.degree. to 600.degree. C.