SU1611899A1 - Method of absorption of fluor gases in supenphosphate production - Google Patents

Abstract

This invention relates to the production of phosphate fertilizers, in particular superphosphate. The purpose of the invention is to increase the degree of absorption of fluoride gases by water. The method of absorption of fluorine gases in the production of superphosphate is carried out with water, which is preliminarily passed through a magnetic field with a strength of 100-120 kA / m with a fluid velocity of 3-4 m / s. 1 tab.

Description

The invention relates to the production of phosphorus fertilizers, in particular superphosphate, to can be used in other areas of the industry - chemical, metallurgical, where it is necessary to absorb fluorine-containing gases by water.

The purpose of the invention is to increase the degree of absorption of fluoride gases.

Example. The influence of the parameters of the magnetic treatment of solutions (the magnetic field strength and the flow rate of the impurity) on the degree of fluorine absorption during the drying of granulated superphosphate is investigated in laboratory conditions. Take 5 kg of ripe superphosphate and place it in a laboratory mill. Shale ash is also fed in portions to neutralize the superphosphate. After each batch is supplied, the mill is turned on for 1 min and then a sample is taken for analysis of superphosphate for the content of free Neutralization of superphosphate (slate ash feed)

stop when the free content in superphosphate reaches 2.5%. Next, the superphosphate is placed in a laboratory granulator - a horizontal rotating drum with a diameter of 300 m and a length of 5000 m. 0.3 kg of retur (fine fraction of superphosphate) and 0.8 liters of water are added to the drum with superphosphate. The granulator is rotated at a speed of 35 rpm for 10 minutes. The resulting superphosphate wet granules are placed in a laboratory drum dryer with a diameter of 500 mm and a length of 1400 mm, having a rotation speed of 22 rpm. Air heated to 96-98 is passed through a laboratory drum dryer. With an electric spiral heater. Next, the air from the dryer is directed by means of an axial fan to the absorption of gases in a laboratory column with a ceramic nozzle irrigated with water circulated around the circuit by means of a pump. In experiments with magnetic treatment, an appa is installed on the water circulation line (L

with

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The magnetic processing speed, the magnetic field strength is 100-120 kA / m and the water velocity in the interpolar gap of the apparatus is 3-4 m / s. 45 minutes after the start of drying, the concentration of fluorine gases by the photoelectrocolorimetric method using a titanium chlorochromo compound was determined in the air leaving the absorption column. The concentration of fluorine gases in the air at the inlet to the absorption column is also determined.

Dp to obtain comparative data in parallel conducted a similar experience. by a known method without magnetic treatment of water supplied to the irrigation of the absorption column.

.Efficiency of the proposed method

ba is characterized by the coefficient of absorption of fluorine gases

20

TO.

WITH, (

| where c. and C

concentration of fluoride gas inlet and outlet

; absorption column

I accordingly.

; The results of the experiments are given in the table.

: It follows from the data in Table I that the magnetic treatment of the surrendered to the absorption of fluorine gas | water allows a significant increase in the absorption coefficient. The greatest positive effect is observed at a magnetic field strength of 100-: 120 kA / m and at a fluid velocity of 12-4 m / s. With these values of the parameters of magnetic treatment, the absorption coefficient of fluorine gases increases from 0.40 (by a known method to 0.72-0.78, i.e. “2 times.

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0

five

0

five

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It is not advisable to create a higher magnetic field and a higher speed from a technical and economic point of view, especially since a further increase in these parameters does not lead to a significant increase in the positive effect.

Magnetic treatment of circulating water containing insoluble colloidal silica impurities leads to coagulation of these impurities, their coarsening and removal from solution due to deposition in the apparatus in the form of sludge. At the same time, the concentration of SiC in water decreases, which, according to the Le Chatelier principle, causes an equilibrium shift of the heterogeneous reaction to the right, i.e. towards a more complete interaction of fluoride compounds with water.

The use of the proposed method at the stage of production of superphosphate in comparison with the known one provides the following advantages: reduction of the damage caused to the environment by emissions of fluoride gases; improving the use of raw materials by reducing the loss of fluoride into the atmosphere and the possibility of using it, for example, extracting it from the irrigation water in the form of fluoride salts.

Claims (1)

Invention Formula The method of absorption of fluorine gases in the production of superphosphate by absorbing gases by water, in order to increase the degree of absorption of fluoride gases, water is preliminarily passed at a speed of 3-4 m / s through a magnetic field. with a intensity of 100-120 kA / m. Table continuation 100 100 1.00 100 120 120 120 120 140 140 140 3 4 5 1 3 4 5 3 4 21.0 11.0 9.1 13.8 20.7 8.2 7.4 12.8 17.9 17.8 0.401 0.662 0.719 0.579 0.410 0.754 0.784 0.602 0.448 0.473