Abstract: A process for reclaiming a consumed grinding suspension which has been used for machining silicon, quartz or ceramic is made from a cutting fluid, in which abrasive grain and abraded material are dispersed. In a first process step, the grinding suspension is carefully separated, by means of a drying step, into a solid component and a liquid component. In a second process step, the solid component is separated into abrasive grain and abraded material by a separation method.

Abstract: The invention is a device for the dry purification of gases under low pressure by adsorption of the impurities, particularly hydrogen sulfide, on a fixed bed of adsorbent material. The entire surface of the gas adsorbent material is spread as a loose layer on the ground and is covered with a gas-impermeable plastic or with a gas-impermeable fabric. Underneath the gas purifying adsorbent layer is a layer of gas-permeable material, in which are embedded gas-carrying pipes which are connected to a collecting pipe laid underground. Gas carrying pipes are arranged between the surface of the particulate adsorption layer and the cover.