Abstract: The invention relates to a method and a device for electrowinning of zinc from sulfate solutions. The electrolyzer for zinc extraction according to the invention includes a bath-reactor which is equipped with power supply buses, a pipeline of two pipes for supplying the electrolyte, cathodes, anodes, plastic strips along the height of the anodes, an overflow for electrolyte discharge by gravity. The cathodes have an area of 3.5-10 m2. The height of the electrolyzer is at least two times greater than its width, and the length of the electrolyzer depends on the number of the electrodes. The bottom of the electrolyzer is divided by a groove along the length of the bath.

Abstract: The method for the production of sulphur trioxide, operating in a non-stanary regime, intend for sulphuric acid production.The aim of the present invention is to provide a method for the production of SO.sub.3 by catalytic oxidation of SO.sub.2, contained in an inlet gas flow, providing a stable regime of operation of wide limits of variation of the flow rate and the concentration of SO.sub.2 in the input gas.The essence of the invention is in this, that between the two layers of the first step of oxidation in a two-step three-layer contact apparatus, the gas flow is partially cooled in an inner heat-exchanger-mixer and part of the heat of the reaction of oxidation of SO.sub.2 in the first stage of oxidation is passed to the second stage of oxidation by means of the gas flow coming out of the intermediate absorption, containing unoxidized SO.sub.2 from the first stage.