Abstract: The present invention solves the problem of managing resin-containing waste liquors within the cellulose pulp industry. The invention relates to a method for purifying resin-containing waste liquor in the manufacture of cellulose pulp, in which method a pH-adjusting chemical is, when necessary, added to resin-containing waste liquor removed from the cellulose pulps, so that the pH of the waste liquor will lie within the pH range 1-7, and in which a water-soluble organic polymer is added to the waste liquor in the form of a forwardly moving liquid stream. The method is characterized by dividing up the requisite amount of polymer into part quantities which are introduced into the liquid stream on at least two occasions, by subjecting the liquid stream to a pronounced shearing and/or turbulent treatment process, and by subsequently separating agglomerated resin from the waste liquor.

Abstract: A method for controlling a crushing gap width of a gyratory crusher of the kind including a crusher head is disclosed. The crusher head of the crusher is driven by a power unit and is positionally adjustable in relation to a crusher shell by a hydraulic motor. The hydraulic motor moves the crusher head of the crusher, thereby adjusting the crushing gap width. A power consumption of the crusher, pressure load on the crusher head, and the width of the crushing gap are determined continuously. The crushing gap width is controlled by being adjusted when the gap width is, above a pre-determined minimum gap width value, substantially in accordance with a control function which depends on both the power consumption and the pressure load, and which is so selected as to provide an intended crushing effect the material being crushed.

Abstract: The present invention relates to a method for treating lakes with selenium with the intention of lowering the mercury content of fish, and is characterized by supplying to the lake selenium in the form of a selenium salt incorporated in a carrier material capable of dispensing selenium to the surrounding water substantially continuously and in a controlled manner. The carrier material is preferably a rubber-based or silicon-based and biologically degradable material. There is preferably maintained an effective selenium level of beneath 10 .mu.g.

Abstract: The invention relates to an electrowinning cell for extracting metals in powder form from solutions, and simultaneously oxidizing the solution. The cell is characterized by radially extending electrodes comprising mutually alternating anodes and cathodes; by a diaphragm which delimits separate anode and cathode chambers, of which the cathode chamber forms an outer space; and a stirring means arranged in the anode chamber and operative to ensure a large flow of electrolyte across the anode surfaces. The base of the cathode chamber is preferably conical in shape.

Abstract: The invention relates to a method for selectively recovering lead from complex sulphidic non-ferrous metal concentrates in an electrolytic cell incorporating at least one anode and one cathode and an electrolyte containing chlorine ions, at a temperature beneath the boiling point of the concentrate-containing electrolyte and at a pH beneath 7. Sulphur present in the concentrate is converted substantially into elementary form, and at least the major part of the lead content passes into solution and is then precipitated selectively by cathodic processes. The invention is characterized in that the concentrate is slurried in an electrolyte having a chloride-ion strength above about 2 M, preferably in the range 3-5 M, to form a suspension which is caused to flow into contact with or adjacent the surface of anodes located in the cell; and in that the highest possible anodic current density considering required selectivity is maintained during the electro-winning process.

Abstract: A water purifying method, particularly a sewage purification method, for eliminating nitrogen therefrom, in which (a) the water is subjected to a preprecipitation process with the aid of trivalent and/or multivalent metal salts for prereduction of incoming contaminants; (b) the NO.sub.3 present is reduced to nitrogen gas by anaerobic fermentation, in which readily decomposed organic material serves as the carbon source and gives by preprecipitation according to (a) an optimum nitrogen reduction in respect of each sewage category; (c) the ingoing ammonium nitrogen is oxidized to nitrate by aerobic fermentation while simultaneously blowing-off nitrogen-gas bound to the water, wherein water (sewage) that contains nitrate is passed to the reduction stage (b) and bacteria-containing sludge is passed from the aerobic stage to the anaerobic stage, and wherein process stages (b) and (c) can be carried out in any desired order subsequent to step (a).

Abstract: The present invention relates to a method of excavating a storage complex in rock for storing radioactive material, or other harmful material. The complex to which the method relates comprises a hollow body which is formed from a solid material and the interior of which constitutes a storage space for the radioactive material or other harmful material to be stored. The hollow body is located in an inner cavity (4) which is excavated from the rock and which has larger dimensions than the hollow body. The hollow body is spaced from the outer walls of the inner cavity (4) such as to leave a space which is filled with an elastoplastic, deformable material. At least one vertical shaft (2) is driven partially through the location of the space (4), and the space is excavated from the bottom of the shaft (2) and upwards, while filling the space or cavity (4) thus formed substantially at the same time as the cavity is formed.

Abstract: The present invention relates to a method for manufacturing zinc hydrometallurgically from zinc-containing starting materials. The method comprises one or more leaching stages, one or more solution purifying stages and one or more electrowinning stages for recovering metallic zinc from the leaching solution obtained. The method is operating with a closed solution circuit. A predetermined part volume of the solution obtained in the electrowinning stage or stages is withdrawn and concentrated by evaporation so as to precipitate any magnesium and manganese present in the part volume in the form of metal salt crystals. The precipitated crystal mass is separated from the residual liquid phase. The liquid phase in this manner purified with respect to magnesium and manganese can be recycled to the leaching process or utilized for some other purpose.

Abstract: A rock cavity for storing fluids, solid products for some other purpose, such as the protected manufacture or production of goods, comprising a substantially vertical, cylindrical rock cavity comprising a conical top section (14), and a conical or horizontal bottom section (15) and a vertical section (1) extending therebetween and presenting in cross-section a polygonal shape, wherewith vertical shafts (11) are located in at least half the corners of the polygon.

Abstract: The present invention relates to a structure for storing radioactive material in rock, having a body (4) for accommodating radioactive material, the body (4) being encompassed by rock around which a cavity (3) may optionally be formed, there being arranged in the cavity a barrier (5) comprising a water-swelling elastoplastic material. The body (4) includes a substantially vertical central shaft (8), a vertical shaft (10) of annular cross-section and extending concentrically with the central shaft (8), and a plurality of vertical drifts (12) located at a distance from the center axis of the central shaft (8).

Abstract: The invention relates to a method for working-up valuable metal-bearing waste products, particularly but not exclusively copper scrap, containing a substantial amount of organic constituents, to a product form suitable for recovering the valuable-metal content, while expelling the organic constituents by pyrolysis and/or combustion in a reactor which rotates about its longitudinal axis and which is provided with a common reactor charging and reactor emptying opening. This invention is characterized in that, subsequent to expelling at least the major part of the organic content, the resultant residual products in the reactor are brought into close contact with a molten bath which is obtained from any metal-sulphide material and which contains at least a metal-sulphide phase or a metallic phase capable of dissolving at least the valuable-metal content of the residual product.

Abstract: The present invention relates to a granular product comprising a reaction product between magnesium oxide and phosphoric acid; this product exhibiting high solubility in neutral citrate solubility tests and the weight ratio of magnesium to phoshorous being smaller than 1.8:1.

Abstract: The present invention relates to a method for comminuting a coarse lump mineral material in an autogenous grinding system, in which feed to the grinder is divided into a coarse fraction and a fine fraction. The coarse fraction is coarser than the inflection point on the coarse side of the knee of the particle size distribution curve of the charge of said autogenous grinder; the fine fraction is substantially all finer than the point of intersection between two tangents drawn between the adjacent inflection points on either side of the knee of the particle size distribution curve of the charge. The ratio between the amounts of fractions is determined on the basis of achieving a given charge quantity for a particular, selected set point power value for the mill in question, and determined with respect to a selected degree of grinding. Grinding efficiency is greatly increased by selecting feed sizes in accordance with the present invention.

Abstract: A method and apparatus for distributing a water purifying chemical, particularly a flocculating-agent concentrate, throughout a stream of water to be purified. In accordance with the method, the concentrate is introduced into the stream of water transversally to its direction of flow under the action of rotational motion, to achieve a distribution time of at most one second.

Abstract: The present invention relates to a storage plant for storing radioactive material in rock formations, the plant comprising a cavity (4) for accommodating radioactive material, the cavity (4) having therearound a rock shield (6) in which a further cavity (7) is optionally formed, there being arranged in the optional cavity a barrier (8) comprising a resilient material which swells in water. Arranged around the second cavity (7) and spaced therefrom is a helical tunnel (12). Entry tunnels (13) extend from the helical tunnel (12), in towards the remaining parts (4,7) of the plant. The invention is characterized in that at least one cage of substantially vertical drill holes (14) is arranged around the plant, preferably in connection with the helical tunnel (12), for taking-up and conducting away water arriving at and departing from the inner part of the storage plant.

Abstract: A method for the purification of gases containing mercury and simultaneous recovery of the mercury in metallic form by a process where primarily a reaction takes place between metallic vapory mercury and mercury (II)-chloride compounds in solution in a liquid phase, during which the formation and deposition of only slightly soluble Hg (I)-chloride (calomel) occur, the deposited calomel being oxidized to easily soluble Hg (II)-chloride compounds by the adding of chlorine, and metallic mercury and at least some of the chlorine used being recovered by electrolysis of said formed Hg(II)-chloride.

Abstract: A method for assaying dry gases comprising sulphur trioxide capable of forming a mist. The gas to be assayed is introduced into a closed space and contacted therein with air comprising normal humidity which reacts with the gas to form a mist, whereafter the light-extinction properties of the mist are measured.

Abstract: The invention relates to a method for preparing a sulphidic concentrate which is intended for further processing to copper and/or precious metals and which contains high percentages of arsenic and/or antimony, and possibly also bismuth in quantities likely to disturb subsequent processing stages, by partially roasting the concentrate in a fluidized bed, so as to eliminate substantially all the arsenic present and a major part of the antimony and/or bismuth. According to the invention, the concentrate and gas are supplied to a fluidized-bed reactor, and are there heated to a minimum temperature above the splitting or decomposition temperatures of the complex minerals containing arsenic and/or antimony and bismuth present in the concentrate. The oxygen potential in the reactor is regulated, so as to prevent the formation of non-volatile compounds of said impurities. The residence time of the concentrate in the reactor is controlled in a manner to ensure a given minimum elimination of the impurities.

Abstract: The invention relates to a method for pyrometallurgically recovering the precious metal content, such as gold, silver and platinum metals, of halogen-bearing materials rich in silver. The material is caused to rapidly disperse in or be finely distributed throughout an at least partially molten charge containing a non-oxidic metal-containing phase having the ability to dissolve precious metals and to substantially lower their chemical activity. The halogen content of the material herewith reacts with any fluxes or metals of high chemical activity present in the furnace charge, while forming metal halogenides. The halogenides formed are separated by slagging and/or volatilization, and the precious metals are recovered from the molten charge, depleted of halogens, in a conventional manner and with regard to the charge phases.

Abstract: The invention relates to an improvement in a method for recovering metal values from copper-containing and/or precious-metal containing materials which also contain antimony and/or bismuth in such high quantities as to render working-up of the materials with conventional metallurgical processes difficult or impossible. In accordance with the improvement, the material is subjected to a chlorination volatilization process in a manner to bring the antimony and/or bismuth content of the material to a predetermined low level acceptable for the continued working-up of the material in conventional process stages, while maintaining the metal values of the material in a substantially unaffected form. The volatilization process is best carried out at temperatures of between 450.degree. C. and 750.degree. C., preferably between 550.degree. C. and 650.degree. C.