SU1315446A1 - Method for processing phosphate raw material containing fluorides - Google Patents

Abstract

The invention relates to a method for processing phosphate feedstock with a nitrogen-acid decomposition of the latter to produce a fluorine-containing sludge and a nitrogen-phosphoric acid solution and can be used in the production of NP-fertilizers. The aim of the invention is to increase the degree of fluorine recovery to the precipitate and increase the filtration performance of the precipitate. Phosphate raw materials containing fluoride compounds are treated at 50-60 ° C with nitric acid, previously mixed with hydrofluoric acid and hydrogen at a HNOj: H2SiFb weight ratio of 1: (0.06-0.10). The precipitated calcium silicofluoride precipitate is separated from the nitrogen-phosphoric acid solution by filtration. The degree of extraction of fluorine in the sediment is 87.5-93.5%, the filtration rate of this precipitate is 168-222. 2 tab. o (l with:

Description

one

The invention relates to a process for the processing of phosphate raw materials by nitric acid decomposition of the latter to produce fluoride-containing sludge and a nitric-phosphoric acid solution and can be used in the manufacture of NP-fertilizers.

The purpose of the invention is to increase the degree of fluoride extraction in the precipitate and increase the filtration performance of the precipitate.

Example 226.8 g of 60% nitric acid is mixed with 20.7 g of 46% hydrofluoric acid (the HNOg ratio is 1: 0.07). The resulting mixture of acids is treated with 100 g of apatite concentrate (3 g, % fluorine) at 60 ° C. After 1 h, the resulting pulp containing a nitrogen-phosphoric acid solution and a precipitate of calcium fluoride is dispersed under vacuum on a Buchner funnel. 300 g., 5 g of a nitrogen-phosphorus-acid solution ( About ,, 37% fluorine), which is processed into MP-fertilizer, and 47 g of calcium silicate fluoride precipitate J containing 20.2% fluorine. The degree of extraction of fluoride and raw materials into the sediment is 89r5%. The filtration rate of the sediment is 190 kg / m.h.

Table 1 shows the effect of the mass ratio of HNO; HjSiF on process indicators „

Table

; 0.05

By the proposed method 85,0 1bO, 0

87.5 91.0

68.0

194.0

55

93.5 222.0.

68.0 290 55 According to a known method

74s6-85 6 29-42 25-35

44.0

55

154462

From the data table. 1 it follows that when the ratio is less than 1: 0.06 and more than 1; 0.0, the degree of fluorine recovery is lower; than, according to the known method, one of the goals is not achieved. Frtratratsii productivity in all interval is higher than by a known method. Example 2. 226.8 g of 60%

Nitric acid is mixed with 29.6 g of hydrofluoric acid (I: OslO ratio) c The resulting mixture of acids is treated with 100 g of apatite 5 concentrate (Zr1% fluorine) at, After i h the resulting pulp is filtered through a Büchner funnel under vacuum and get 305 g of nitrogen-phosphoric acid solution (0.26% fluorine),

20 which is processed into NP-fertilizer and 51.4 g of precipitate of silica-fluoride by liquidation (2556% of fluorine) o. The degree of extraction of fluorine in the sediment is 94.7% of that introduced with the raw material. Filtration capacity 182.

The results of the effect of treatment temperature on the process indicators are given in Table. 2 (mass ratio HNOj; is 1: 0.10).

Table 2

thirty

From this table, 2 it follows that

at a temperature below, the filtration efficiency decreases due to a higher viscosity of the pulp. At temperatures below 60 ° C, fluorine is removed as a result of extraction due to decomposition

Chlorine calcium fluoride with calcium fluoride and silica dioxide, jammed day decomposition of raw materials.

. 313154464

Claims (1)

The claim of the invention by filtration, about tl and h and torn and and With the fact that, in order to improve the method of processing phosphate sulfur, the degree of extraction of fluorine in the precipitate containing fluorine compounds and filtering performance, including the processing of raw materials nitrogen - radio sets, nitric acid with a preliminary acid with an increased temperature is mixed with silicofluoride-water with the formation of a precipitate with silicofluoric acid at a mass ratio of calcium and nitric-phosphoric acid acid HNOj: equal to 1: th solution used for obtained: (0,06-0,10), and processing is carried out at Cheney fertilizer, separating the precipitate from the Yew -50-60 C.