At the moment, the pyrometallurgical method of obtaining metals leads to the formation of a huge amount of solid waste and is not effective in the processing of oxidized nickel ores, which are characterized by a high content of magnesium oxide. The article is devoted to the development of a technological scheme for the complex processing of oxidized nickel ore from the Serovskoe deposit by a hydrometallurgical method, which allows the most complete use of the components of raw materials (SiO2, MgO, Fe2O3, Al2O3, etc.) containing lizardite 1T, nimite, talc, antigorite and quartz. Nitric acid was used as a leaching agent. The conditions for opening the ore are determined: the concentration and amount of nitric acid; process duration. A portion of the original ore was dissolved in acid. The resulting pulp was diluted with water, a flocculant was added and filtered while hot. Silica precipitate was subjected to wet magnetic separation. To concentrate the Fe3+ and Ni2+ ions from the nitric acid leaching solution, a suspension was used as a precipitant, which is obtained by the interaction of magnesium oxide with an aqueous solution of magnesium nitrate. Iron(III) and aluminum hydroxides precipitate at pH = 2-4. After filtration and with the addition of a precipitant to pH = 7-8, nickel is isolated in the form of nickel(II) hydroxide with a high content of magnesium oxide. Therefore, it was used in the second stage to precipitate nickel(II) hydroxide from a new portion of the solution. The concentrate obtained after the second precipitation stage contains 39.37% nickel(II) oxide. From a pure solution of magnesium nitrate, crystals of magnesium nitrate hexahydrate containing 99.8% of the main substance were isolated, and high-purity magnesium oxide was synthesized during thermal hydrolysis. During the condensation of the emitted nitrous gases, nitric acid with a low content of nitrous acid is regenerated.