Abstract: A novel material can be obtained by chemical reaction from elemental or alloyed silicon powder, to which fillers are optionally added. The novel material, which can be worked mechanically, can be further refined by means of subsequent heat treatment and/or surface coating, and can in many cases be used instead of polycrystalline or sintered silicon.

Abstract: A ceramic material made of a skeleton reaction-bonded silicon powder is distinguished by an open-cell pore structure produced by using a matrix of an appropriately shaped polyurethane foam structure. For the preparation, a foam matrix is coated with a suspension of silicon powder, synthetic resin and solvent and is subjected to a heat treatment, during which the foam matrix is expelled and the silicon is stabilized. The thermally and chemically stable product can be used, for example, as a filter medium for metal melts, as a catalyst carrier, or as a boundary medium between the flame zone and unignited combustible mixtures in burners.

Abstract: A process for continuous or batchwise melting of silicon powder in particular, powder having a large amount of fines, and a melting crucible for carrying out this process are specified. The melting crucible is designed so that a melt pool having a certain minimum height and which is covered by unmelted silicon powder is provided. Thus, added material first comes into contact with silicon powder which is already present and only gradually reaches the melting zone. The amount of melt produced which exceeds the minimum height of the melt pool flows out of the melting crucible. The minimum height is maintained in the process by using a crucible which has a siphon-like outlet in the base.

Abstract: A spacer for automatic parallel aligning and clamping of the blades in a gang saw which uses spacer plates which are trapezoidally enlarged toward their top and bottom edges. The supporting inner surface of the frame portion is designed as clamping mouth bevelled to fit the spacer configuration.

Abstract: A process and apparatus for the manufacture of silicon blocks having a columnar structure comprising monocrystalline crystal zones having a crystallographic preferred orientation. In a casting process, each mold filled with molten silicon is transferred, before the silicon has solidified completely, to a separate crystallization station where the silicon can then crystallize completely. During this process, the exposed surface of the silicon is maintained in a molten state until the end of the solidification process has almost been reached. The process allows the various, necessary steps to be carried out simultaneously and yields high-quality solar cell base material.

Abstract: A process and an apparatus for carrying out a process for multiple lap cutting of solid materials, especially those having rectangular or square cross sections, in which the workpiece is subjected, during the cutting operation, to a rotating motion thereby improving the quality of the discs and increasing the cutting efficiency.

Abstract: A process for the purification of silicon by the action of one or several acids, wherein silicon is established as a stationary phase and one or several acids are caused to form mobile phases for traversing the stationary phase under pressure and absorbing the impurities from the silicon during the passage, leaving behind the silicon with a higher degree of purity.

Abstract: The invention provides a process for the manufacture of coarsely crystalline to monocrystalline sheets and/or plates of semiconductor material of preferred orientation. A meniscus of molten semiconductor material comes in contact with a moving, cooler substrate of the same coarsely crystalline to monocrystalline semiconductor material, during which, while transferring the preferred orientation, a thin sheet of the semiconductor material is pulled onto the substrate and, after cooling, becomes detached from the substrate. The substrate can be reused as often as desired.

Abstract: The invention makes it possible to manufacture silicon wafers having vertical p-n junctions as the basic material for solar cells. As a result of simultaneously adding certain dopants that act in the silicon crystal as donors and certain dopants that develop acceptor properties and also as a result of measures that result in a periodic change in the crystal growth from a low rate v.sub.n to a high rate v.sub.n, p- and n-conductive zones are produced in the silicon, each having a total length of from 5 to 2000 .mu.m.

Abstract: Competitive current generation by the exploitation of solar energy requires cheap solar cells. A process is described which makes it possible to manufacture from silicon a base material for solar cells of this type in an economical manner and in large quantities. This is achieved by bringing silicon from a supply container into contact with a non-elemental lubricating melt, which is immiscible with silicon but will not wet silicon and has a melting point below that of silicon, and by drawing off a silicon film, sliding on this lubricating melt, and solidifying the silicon continuously by cooling to below its' melting point.

Abstract: A method of purifying metallurgical-grade silicon for the production of silicon solar cells is provided, in which metallurgical-grade silicon is dissolved in aluminum and brought into contact with an aluminum sulphide extraction melt. Thereafter, the silicon is crystallized out and separated off by cooling the melt to a minimum temperature of 600.degree. C. The aluminum melt remaining can then be recharged with silicon, heated, brought into contact with the extraction melt, so that additional silicon can be crystallized out.