Abstract: A method of producing a siliceous cover layer on a semiconductor element or wafer so that the temperature coefficient of the cover layer is approximated to the temperature coefficient of the semiconductor wafer, comprises distributing a combined emulsion over the wafer by centrifugal force. The combined emulsion is formed by making a mixture of a first emulsion of a non-doped, pure, silica emulsion and a second emulsion of a heavily-doped silica emulsion and adjusting the ratio of the first and second emulsions so that the temperature coefficient of the formed layer will be substantially identical with the temperature coefficient of the semiconductor element in form of a wafer or die. After the cover layer is hardened, the peripheral bead which forms from the emulsion mixture is etched off so that the exposed semiconductor surface, as well as the front side of the semiconductor die or wafer, are ready for epitaxial coating.

Abstract: A process for treating an aqueous acid solution containing at least one element selected from the group of elements consisting of As, Sb and Bi, said process comprising contacting the aqueous solution with an organic phase comprising an organophosphoric compound having the general formula (RO).sub.3 P = O wherein R represents an unsubstituted or substituted alkyl, aryl or aralkyl group, while maintaining a temperature of between 10.degree. and 60.degree. C and an organic phase/aqueous phase ratio of between 0.1 and 5, whereby the elements of said group and acid are extracted from the aqueous phase to the organic phase, and separating the resultant pregnant organic phase from the aqueous phase.

Abstract: A process for separating an electrolytic deposit of metal from a cathode, in which the bath-level edge of the said electrolytic deposit is locally heated at a plurality of spots to form local gaps between the said edge and the cathode, then the local gaps are enlarged by means of knives so as to unite them together and to form a large gap along the said edge, and then a wedge is operated from the said large gap to separate the entire deposit.

Abstract: Removing the crust of oxide formed on the surface of a continuously casted copper bar by projecting a liquid (water or a rolling emulsion) under pressure of between 20 and 60 atmospheres against the periphery of the bar, the flow of the liquid under pressure being less than 50 liters/minute.

Abstract: Metal values are extracted from manganiferous ocean floor nodule ore by treating the ore with hydrochloric acid, thereby producing chlorine and a starting pulp containing a solution of the metal chlorides and a solid residue. The starting pulp is subjected to at least two subsequent acidifications with HCl, each acidification being followed by addition of fresh ore, thereby producing chlorine and a final pulp containing a concentrated solution of metal chlorides and a solid residue. The solid residue is separated from the concentrated solution and substantially all the metal values, except manganese and alkali and alkaline earth metals, are separated from the solution. The manganese is separated from the solution by treatment with chlorine, at least the major portion of which was produced in the preceding leaching steps, while maintaining the solution at a pH of between about 3 and 7 by addition of a neutralizing agent such as MgO or Mg(OH).sub.2 whereby the manganese is precipitated in the form of MnO.sub.

Abstract: A mold for the continuous casting of metals, in which at least its inner part is made of a refractory material chosen from the group of materials comprising tantalum, niobium, tantalum-base alloys and niobium-base alloys.

Abstract: A mold with a cooling jacket for the continuous vertical casting of metal billets, comprising between the lower part of the mold and the jacket a tubular wall the upper part of which is surrounded by ribs forming with the external side of the wall and with the internal side of the jacket a plurality of channels, said tubular wall forcing the cooling liquid introduced laterally into the jacket first to rise, then to divide itself regularly between the said ribs and to form simultaneously a laminar flow, then to flow down in that state along the mold and to leave in that state the cooling space through an annular slot.

Abstract: A process for the manufacture of copper wire rod, in which liquid copper is cast in a continuous casting machine provided with an inclined straight moulding cavity to produce a continuous bar of copper, comprising guiding said bar as it leaves the casting device towards a horizontal rolling machine known "per se" along a curved path, the maximum curvature of the curved path being less than 0.25 m.sup.-.sup.1 thus preventing the formation of cracks in the hot bar, and converting the said bar into wire rod in the said rolling machine.