| 摘要 |
FIELD: fertilizers, chemical technology. ^ SUBSTANCE: invention relates to manufacturing mineral fertilizers by method of nitric acid decomposition of Vyatsko-Kamsky phosphorite at stage of nitric acid extract preparing. Decomposition of phosphorite is carried out with 30-58% nitric acid at temperature 15-25°C, prepared suspension is heated to temperature 55-60°C, kept at this temperature for 10-15 min and nitric acid extract is separated from precipitate. The decomposition process is carried out for 60-120 min and before decomposition phosphorite is subjected for alkaline treatment. Method provides decreasing degree of iron conversion in nitric acid extract from 64% to 36%. ^ EFFECT: improved preparing method of extract. ^ 5 cl, 5 ex |
