Abstract: A stream of gas containing pyrophoric dust and oxyen is passed through a chamber that is equipped at the inlet with burners and sprinklers the operation of which is controlled in such a way that the stream of gas has for at least 1 second a temperature of at least 270.degree. and that the temperature of the stream of gas does not exceed 500.degree. C. Thereby the pyrophoric dust, that is present in the stream of gas is oxidized whereby is looses its pyrophoric character. The stream of gas is thus optimally conditioned to be filtered in a bag filter installation.

Abstract: The alloys contain, besides zinc and unavoidable impurities,0.05-0.8% of Pb andeither 0.005.1% of Al and 0.0005-0.1% REM, REM being a rare earth metal or a mixture of rare earth metals, or0.005-1% of Mn or0.005-1.5% of a mixture of Al, REM and Mn.These alloys have a higher mechanical strength and a better resistance to corrosion than the known alloys with Pb-Cd or Pb.

Abstract: Metallic pieces of predetermined shape, e.g., anodes, are continuously manufactured from molten metal, e.g., impure molten copper, by continuously casting the molten metal in an inclined mold cavity (13) formed by two endless moving belts (14( and (15) and by two moving side dams (20) and (21) so as to produce a hot metallic strip (4), and by cutting the hot strip, when it has left the mold cavity, with at least one plasma torch (10) along a profile (27) such that anodes (11) with a low waste coefficient are obtained. In this way, flat copper anodes with a thickness of between 40 and 50 mm can be produced.

Abstract: A process using an extractant, that consists on the one hand of an active component being substituted 8-hydroxyquinoline and on the other hand of by-products of the manufacture of said extractant, said process being characterized in that the extractant contains at least 90 wt % of the active component.

Abstract: A zinc base powder for alkaline batteries consists of 0.05 to 3% of mercury, 0.003 to 0.2% of bismuth, 0.01 to 0.08% of lead, the rest being zinc. This powder has an excellent resistance to corrosion in alkaline medium.

Abstract: Tantalum or niobium in the form of powder or pieces containing volatile impurities, e.g. sodiothermic tantalum powder, is first converted into crude cast metal by plasma melting and then the crude cast metal is refined by electron beam melting.

Abstract: The spent anodes to be stacked are vertically suspended by their lugs to hooks.The anodes are lifted from the hooks and then rotated alternately 90.degree. and -90.degree. around a horizontal axis; the rotated anodes are lowered to a lower position wherein they are released; the released anodes form a pile on a support positioned under said lower position; and the support is lowered in such a way that the top of the anode pile being formed on it remains under said lower position.

Abstract: Starting from a homogeneous molten bath composed of zinc, mercury and possibly other elements, an alloy powder with substantially homogeneous particles is prepared and that alloy powder is made to react with metallic mercury or with a mercury compound, thereby producing an alloy powder enriched with mercury.

Abstract: Process and apparatus for separating a suspension bar (14) from an electrode (11) that is vertically suspended by this bar and that comprises, besides this bar, an electrolytic plate (12) and one or several suspension loops (13) fastened to the plate, the suspension bar extending through these loops.The suspension bar (14) is first relieved of the weight of the plate (12) by bringing the electrode (11) in a horizontal position in which its plate (12) is caused to rest on a support (34 or 34').The position of the bar (14) is then changed with regard to the position of the plate (12) by moving the support (34 or 34') with the plate (12) in a direction parallel to the longitudinal axis of the bar (14) while retaining the latter.

Abstract: A process for defluorinating a solution of a sulphate of Zn, Ni, Cd, Mn and/or Mg, in which Al.sup.3+ and PO.sub.4.sup.3- ions are added to the solution, then the solution is neutralized up to a pH higher than 4 and lower than that one that causes a substantial precipitation of Zn, Ni, Cd, Mn and/or Mg, thereby producing a fluorinated precipitate, and the precipitate is separated from the solution.

Abstract: In a process for producing sulphuric acid from roasting gas containing SO.sub.2, H.sub.2 O and Hg, comprising the steps of(a) drying the gas with H.sub.2 SO.sub.4(b) subjecting the gas to a catalytic oxidation treatment so as to produce a SO.sub.3 rich gas, and(c) absorbing the SO.sub.3 in concentrated sulphuric acid, while maintaining the concentration of this acid at its initial value by addition of diluted sulphuric acid, the gas from step (b) is scrubbed with oleum, thereby producing in step(c) H.sub.2 SO.sub.4 with less than 0.1 mg/l of Hg.

Abstract: A process for separating trivalent iron from an aqueous chloride solution comprising contacting the aqueous solution with an organic phase containing an organophosphoric compound as an extracting agent for trivalent iron and at least 40 percent in volume of a long chain aliphatic alcohol, separating the iron-loaded organic phase from the aqueous solution, and re-extractng the iron from the iron-loaded organic phase by contacting the latter with water or acidulated water so as to produce an aqueous iron chloride solution.Owing to the high alcohol content of the organic phase, iron can be re-extracted with a small amount of water.

Abstract: In an apparatus for conveying dripping electrodes, a drop collector having a plurality of parallel gutters is coupled to the conveying apparatus by a frame. The gutters are coupled together in one or more series of parallel gutters and are displaced by a motor driven endless chain system between a work position underneath the suspended dripping electrodes and a rest position which permits the electrodes to be inserted into or extracted from electrolysis cells by the conveying apparatus. The gutters include outlet orifices which communicate electrolyte from the dripping electrodes to a reservoir formed in the frame which couples the drop collector to the conveying apparatus.

Abstract: Non-ferrous metals are extracted from iron-bearing scraps by adding the scraps and a slagging agent for iron to a molten copper bath, injecting an oxygen containing gas in the bath and keeping the bath temperature below 1400.degree..The scraps thus undergo an oxidizing smelting in the presence of a molten copper phase and a slagging agent for iron, resulting in a rapid extraction of non-ferrous metals from the scraps into the copper phase and a thorough iron slagging.

Abstract: In an electrolysis apparatus comprisingelectrolytic cells (2), in which groups of electrodes are suspended and the longitudinal walls (17) of which are capped with two rows (19, 20) of supports (21, 22) for the suspension lugs (12, 16) of the electrodes, these rows extending on both sides of a median element (23) of electrical connection, andhandling means (5) for introducing a group of electrodes in a cell and for withdrawing it therefrom,the supports (21, 22) dominate the median element (23) of electrical connection, the lugs (12, 16) of the electrodes suspended in the cells extend beyond their supports (21, 22) and the handling means (5) are adapted to lift the electrodes by the under-side of the extremities of their lugs (12, 16).

Abstract: A substituted 8-hydroxyquinoline is added to the alphahydroxyoxime extractant, which allows extracting germanium at lower acidity and with a better yield.

Abstract: Germanium is separated from an aqueous solution by means of a substituted 8-hydroxyquinoline extractant.Re-extraction of germanium from the extractant is carried out above 40.degree. C. and with an organic phase: aqueous phase volume ratio less than 1, whereby obtaining a high re-extraction yield.

Abstract: A smelting furnace, the refractory sole (3) of which is contained in a metallic casing (5) having expansion joints (6, 7, 7'), comprises means (18, 19) for cooling the expansion joints, these means enabling to solidify actually any liquid phase that might tend to infiltrate into the joints.

Abstract: A multistage liquid-liquid extraction apparatus of the mixer-settler type, which is especially suited for performing liquid-liquid extractions accompanied by the formation of a solid phase, comprises a vessel the side-wall of which defines a cylinder or a regular polygonal body, the vessel being divided by means of radial partitions into sectors, each sector comprising a mixer and a settler, and the mixers and the settlers being located near the side-wall of the vessel.The agitators of the mixers are constituted by pumping turbines; the outlets of the mixers are constituted by weirs located near the side-wall of the vessel; means are provided for making the mixed liquids, discharged at the outlet of the mixers, flow by gravity towards a zone near the axis of the vessel; and the bottom of the vessel is inclined towards the axis of the vessel so as to define a reversed cone or pyramid.

Abstract: An apparatus for separating electrolytic deposits from both sides of a generally vertically suspended cathode includes sets of suction cups which are attached to the deposits on both sides of the cathode. The sets of suction cups are configured and arranged so as to be capable of moving from a first position wherein the sets of suction cups are attached to the deposits to a second position wherein the sets of suction cups are positioned away from the cathode. Arms which are pivotally mounted about a first horizontal axis are connected to the lower edge of a respective set of suction cups by a first jointed coupling which is also connected to the arms. A second jointed coupling is connected to the set of suction cups so as to permit the set of suction cups to pivot about the first jointed coupling. Mechanisms are provided for pivoting the arms about the first horizontal axis and additional mechanisms being pivotally mounted about a second horizontal axis located at a lower level than the first horizontal axis.