Granular nitrogen and nitrogen-potassium fertilizers containing sulfur from the spent acid mixture of nitrocellulose production

Abstract

Abstract In the production of cellulose nitrates, waste is formed of mixtures of sulfuric and nitric acids. Regeneration of these mixtures involves large capital, energy costs and emissions of toxic substances in the air. To solve the environmental problem and improve the efficiency of nitrocellulose production, a method for obtaining granular nitrogen and nitrogen-potassium fertilizers with a sulfur content from spent acid mixtures has been developed. Six variants of fertilizer compositions from the spent acid mixture of nitrocellulose production and two samples of a simple salt mixture with an elemental composition identical to the composition of two samples from spent acids were obtained at the laboratory facility. A complex of studies of the obtained granular fertilizers without adding binders was carried out. To improve the quality characteristics of the granulated fertilizer, repeated preparation of fertilizers with the addition of bentonite clay to the salt mixture before granulation was carried out. As a result, strong, moisture-resistant granules of nitrogen and nitrogen-potassium fertilizer with a sulfur content with low acidity and high bulk density were obtained. The qualitative characteristics of granules obtained from the spent acid mixture showed better results in all experiments, compared to samples of a similar elemental composition obtained by simple mixing of salts.