NOVELTY - The production of ultra-clean silicon to manufacture solar cells, comprises melting impurities contained in a metallurgical silicon that is provided as a starting material in a form of amorphous to micro-crystalline chunks using solidification on a casting mold surface, mechanically removing the impurities from the casting mold to form a silicon block with silicon seed crystal, crushing the silicon blocks through shock- or ultrasonic waves introduced into the casting mold up to grain boundaries and chemically removing the impurities remaining in the silicon seed crystal.    USE - Useful for producing ultra-clean silicon to manufacture solar cells.    ADVANTAGE - The procedure ensures effective production of ultra-clean silicon with a purity of 99.99999% by removing impurities in the silicon grains through the directional solidification.    DETAILED DESCRIPTION - The production of ultra-clean silicon to manufacture solar cells, comprises melting impurities contained in a metallurgical silicon that is provided as a starting material in a form of amorphous to micro-crystalline chunks using solidification on a casting mold surface, mechanically removing the impurities from the casting mold to form a silicon block with silicon seed crystal having a grain size of 100-1000 microns, crushing the silicon blocks through shock- or ultrasonic waves introduced into the casting mold up to grain boundaries and chemically removing the impurities remaining in the silicon seed crystal. The silicon blocks are crushed in fractions of 0.5-1.5 kg. The microcrystalline chunk has a purity of 98-99.5% and grain size of 5-10 microns. The shock waves are produced through a pulsed electric discharge between two electrodes in the water. The first electrode is a wall of a semi-elliptical chamber and the second electrode is placed before the first electrode so that the focal point of the elliptical chamber lies between the two electrodes.    DESCRIPTION OF DRAWING(S) - The diagram shows metallurgical silicon as a starting material.