Abstract: A method for preparing phosphoric acid from calcium phosphate ores, particularly ores highly contaminated with organic compounds, by decomposing the ore with sulphuric acid, wherein according to the invention the process of decomposition of calcium phosphate ores with sulphuric acid and circulating phosphoric acid is carried out in oxidizing conditions provided by a constant supply of ozone to the reaction slurry, preferably to the zone of commencing decomposition of the phosphate ores.

Abstract: The invention relates to RC lines which are used as components in filter synthesis, with resistors and capacitors not being arranged as discrete components alongside one another but as a three-layer structure consisting of two conductive polysilicon layers and an oxide layer located between these in superimposed relation on a semiconductor substrate. The two polysilicon layers form together with the oxide layer a distributed capacitor, with one conductive polysilicon layer constituting an ohmic resistor. The planar configuration of the polysilicon layers and the oxide layer results in parasitic ohmic resistors which impair the electrical properties of the RC line to a considerable extent.