The technological principles for recycling spent sulfuric acid from alkylation of isobutane by olefins were developed. A scheme of technological operations for reprocessing spent sulfuric acid that enabled sulfuric acid monohydrate to be used for the production of sodium and ammonium sulfates was presented. The maximum yields of sodium and ammonium sulfates (up to 90 wt. %) were obtained by extracting organic contaminants with an EtOH:Me2CO mixture (1:1). The obtained sodium and ammonium sulfates satisfied all the requirements for commercial products. The organic contaminants in them were not greater than 0.2 wt. %. The isolated organic component was certified in oil-displacement formulations and feedstock mixtures for production of technical carbon and detergents.