Abstract: A method of extracting iron and nickel from sulphidic iron-nickel-materials and recover them in metallic form. The method comprises leaching the material with an acidic solution in presence of an oxidizing agent, so that substantially the whole quantity of the oxidizing agent is consumed. The obtained leaching liquid is then divided into two parts and one part is led to the cathode chamber, where iron and nickel is co-electro deposited and the other part is led to the anode chamber were the leaching liquid is regenerated before reuse.

Abstract: In a mill drum provided with wear protective linings and ore lifting and carrying means in the form of longitudinal wings comprising an elastomeric material and extending radially inwardly from the lining of the mill drum an arrangement for securely attaching the wings to the walls of said mill drum, comprising at least two contiguous anchoring rods extending in the longitudinal direction of the bases of the wings through longitudinal holes made through the material of the wings, said anchoring rods passing through yoke means, which are recessed in the bases of the wings at a desired pitch or distribution along said bases and being connected to means for pressing the complete wing units against the drum of the mill and for retaining said wings in their mounted position.

Abstract: A method and a device for determining the charging condition of electric accumulators, wherein the potential variations at the electrolyte-electrode interface are time differentiated in order to determine the degree of gas development in said accumulators.

Abstract: The invention relates to a method for selectively leaching at least one of the elements antimony, mercury, arsenic and tin from sulphidic and oxidic materials with alkali sulphide solutions and subsequent electrolytic recovery of the leached elements. The method consists of maintaining the sulphide ion concentration in mol/l multiplied by two and the hydroxyl ion concentration in mol/l at a value of at least 8 and that the quantity of hydroxyl ions is at least in a quantity equimolar to the quantity of sulphide ions. The electrolyses must be effected at an anode current density of more than 1500 A/m2.

Abstract: Processes are provided for the recovering of crude lead from materials containing lead substantially in the form of oxides and/or sulphates. The processes are carried out in a rotary converter with the rotation axis inclined to the plane of the vertical. In the process the materials containing lead are smelted and reduced while the furnace is rotated. Processes are also provided to separate and recover possible impurities of arsenic, antimony and tin.

Abstract: A flotation concentrate in the form of a water suspension is treated with a reagent that nullifies the effect of previously used collectors. The suspension is filtered, and subjected to a mechanochemical treatment that includes chemical conditioning of the mineral surfaces and producing fresh surfaces by grinding with grinding bodies which additionally provide ions that promote selectivity. Grinding efficiency is controlled by the amount of material fed to the mill. The quantity of pulp flowing to the filter is determined and the supply of collector reagent to the filter and the rotary speed of the mill are regulated in response to the flow values.

Abstract: Processes are provided for the autogenous production of crude lead from sulphidic lead concentrates or complex sulphide materials containing lead. The processes are carried out in a rotary converter with the rotation axis inclined to the plane of the vertical. In the process the sulphidic materials are smelted and reduced while the converter is rotated.

Abstract: There is provided an apparatus for taking a sample-flow from a main suspension flow, said apparatus having a first chamber which is adapted to receive said main suspension flow and which communicates with a second chamber via weir means. The second chamber has at the lower portion thereof first and second opening means for dividing the suspension received from the first chamber into a sample-flow and a main residual flow, said first and second opening means communicating with a respective means for exerting on the suspension in the second chamber a counterpressure of such magnitude that the level of suspension therein is substantially the same as the level of suspension in the first chamber and that the speed at which the suspension flows into the first opening means is substantially equal to the speed at which the suspension flows into the second opening means.

Abstract: The method of recovering liquid sulphur dioxide from gases containing sulphur dioxide by washing with water in an absorption plant and then stripping off absorbed sulphur dioxide at subatmospheric pressure. Water is removed from the stripped gasesby cooling and drying and sulphur dioxide is removed by condensation. The whole system is kept at a subatmospheric pressure by pumping off residual gases after the sulphur dioxide condensation.

Abstract: A method for agglomerating finely divided iron oxide material, substantially consisting of hematite and/or magnetite, preferably enriched iron ore concentrates, and hardening the agglomerates thus formed. The fine material is agglomerated by rolling, micropelletizing or other granulating methods to a particle size distribution convenient fluidizing purposes, whereafter the material is transferred to a fluidized bed furnace in which the bed is heated by introducing gaseous or liquid fuel and gas containing free oxygen or by hot gases. The major portion of the material is then removed from the bed in an agglomerated and hardened condition.

Abstract: A process for the production of copper from raw materials containing sulphur, zinc and more than 0.2% Ni calculated on the copper content. The material is melted to matte and the matte converted to white metal, whereafter the white metal is converted to copper and the zinc present in the slag obtained from the matte is fumed off in a furnace therefore. The slag formed during the conversion of matte to white metal is removed and treated in a separate furnace with an amount of copper, iron or nickel sulphide material sufficient to lower the copper content to less than 2%, whereafter the treated slag obtained is charged to the slag fuming surface.

Abstract: A preservative for wood and other organic materials subject to biological deterioration. The preservative contains an amine-forming biologically active metal; polyphosphate, amine, chlorinated phenols and carbon dioxide. The mole ratios between polyphosphate and amine-forming metal is 0.5 - 1.5, between amine and amine-forming metal 1 - 7; between amine and carbon dioxide 1 - 4 and between amine-forming metal and chlorinated phenole, calculated as pentachlorophenol 0.5 - 15.

Abstract: The present invention relates to a method and apparatus for purifying selenium or its alloys by precipitation. The method is characterized in that a smaller portion of a larger amount selenium or selenium alloy is kept at the respective transition temperature between solid and liquid phases while the remaining portion is maintained at a higher temperature for a time sufficiently long to allow a substantial concentration of foreign elements in the smaller portion.The apparatus is characterized in that it consists of a glass vessel having a height approximately 10 times its diameter, provided with temperature indicators governing devices controlling the heat supplied to electrical elements arranged around the vessel, it also being provided with a tightly-fitting hood and a gas evacuation device.

Abstract: A method for roasting finely divided iron sulphide material in a manner to obtain a coarse, substantially sulphur-free product, the sulphide material consisting of pyrrhotite or a finely divided materal derived from a pyritic material in which thermally splittable sulphur has been driven off by partial roasting for example. According to the method, the sulphide material is first agglomerated to a particle size distribution suitable for fluidizing purposes and then roasted and hardened in a fluidized bed, whereafter the material is removed from the bed in a hot state.

Abstract: The invention relates to a method and an arrangement for determining signals affected by disturbance or interference. The affected signals are continuously integrated, either directly or subsequent to suitable transformation thereof, from the very start of a measuring operation. The actual integration value is divided at determined time intervals with the actual measuring time which has elapsed at that moment from the start of said measuring operation. The quotient thus obtained is presented to an observer or a device which is arranged to interrupt the measuring operation when the value presented is substantially constant.

Abstract: A bed comprising fluidized particulate material and having a resistivity (.rho.) between 10.sup..sup.-1 and 10 ohm m is heated in a reaction chamber by means of an induction coil surrounding said chamber. The heat is generated in the bed itself by passing an alternating current through said coil. There is maintained between the least cross dimension (d) of the bed area and the penetration depth (.delta.) of the inductive field a ratio determined by the relationshipd/.delta. = k (0.54 - 0.35 .sup.. 10 log .rho.)where k is a numerical value between 0.2 and 1.5.

Abstract: A bed of coke or other material having a resistivity within the range of between 10.sup..sup.-4 and 10 ohm m is heated in a reaction chamber by means of an induction coil surrounding said chamber. The heat is generated in the bed itself by passing through said coil an alternating current having a frequency of at most ten times the mains frequency. There is maintained between the least cross dimension (d) of the bed area and the penetration depth (.delta.) of the inductive field a ratio determined by the relationship ##EQU1## WHERE K IS A NUMERICAL VALUE BETWEEN 1.1 AND 1.5.

Abstract: A grinding plant for autogenous or semi-autogenous grinding of ores in particular, in separate mills in two steps. The second step uses material from the first step, which is provided with two outlets. The first outlet has holes for discharging relatively finely ground material to be further ground in the second step, and the second outlet has holes for discharging material containing relatively coarse pieces forming grinding media in the second step. A device is provided between the stages to control the flow of coarser material to the second step. Connected to the discharge side of the second step, which is provided with outlet holes as large as the holes for fine material in the first step, there is a means to separate material removed from the second step into a finely ground portion, which is led away, and a portion returned to the first and second steps in proportions adjustable by said means.

Abstract: The invention relates to a method of purifying sulphuric acid containing mercury in a plant for the production of sulphuric acid according to the contact process which involves drying moist roaster gases containing sulphur dioxide in at least two drying towers where the major part of the water content is absorbed in the first drying tower. The sulphuric acid containing mercury is in a quantity suitably measured to maintain the concentration between 70 and 80 percent by weight led to the first drying tower. To the second drying tower is led a sulphuric acid so that the concentration can be maintained between 95 and 103 percent by weight. The mercury is separated from a partial current from the circulating sulphuric acid in the first drying tower.