SU1264969A1 - Method of obtaining granular filtering material - Google Patents

Abstract

1. A method for producing a granulated filtering material for water purification, comprising adding an additive to the clay suspension followed by granulation at 250-400 ° C, characterized in that, in order to simplify the process and increase the filtering capacity of the material, orthophosphoric acid is used as an additive hexametaphosphate. sodium or sodium phosphate monosodium phosphate. 2. The method according to Claim 1, characterized in that the additive is introduced in an amount of 16-33 wt.% In terms of PjO, relative to the weight of the clay.

Description

1 The invention relates to a method for producing a granular filtering material and can be used to purify water in filtration plants with both downward and upward filtration; A method of obtaining granulated filtering material for purifying water is known, which includes the introduction of ground pyrite cinder (in an amount of 2-A wt.% Of the mass of the clay suspension) into a clay suspension, its granulation in a fluidized bed, followed by calcining the granules at 1000–1250 ° C. However, the obtained granules have a low strength and filtering ability. The closest in technical essence and the achieved result is a method of obtaining a granulated filtering material for water purification, including introducing dilomitic lime into an clay suspension in an amount of 15-30 wt.% Of the clay suspension, followed by granulation at 160340 ° C and roasting 700-900 ° C. 2. A disadvantage of the method is the necessity of conducting the firing of the pellets at 700-900 s. In addition, there is a lack of high filtration capacity. The purpose of the invention is to simplify the process and increase the filtration capacity of the material. The goal is achieved by the method, which includes the introduction into the clay suspension of orthophosphoric acid, sodium hexametaphosphate or monosodium phosphate in the amount of 16-33 wt.% In terms of P-jO relative to the mass With its subsequent granulation, clay at 250 -400 ° C. The difference of the method is that as orthophosphoric acid, sodium hexametaphosphate or monobasic sodium phosphate as an additive, ai also the fact that the additive is introduced in the amount of 16-33 wt.%, Calculated on PjOj relative to the mass of clay. Example, Production of a ceramic granular filtering material is carried out on an integrated experimental granulator with a fluidized bed. To obtain a clay slurry, the Cambrian gus of the following 69 chemical composition is used,%: SiO 57.42; , 92; 4.38; FeO 2.28; Na2.0 5.96; 1.54; TiOg 0.26; CaO 0.47; MgO 0.26. Loss on ignition 3.51%. Out of 200 g of clay with a moisture content of 4.79% (solid phase 191.42 kg, water 9.58 kg) 70% suspension of clay is prepared (0.72 kg solid phase per 1 liter of suspension). As an additive, orthophosphoric acid, sodium hexametaphosphate are used. or monobasic sodium phosphate in an amount of 16-33 wt.% in terms of P-Oj relative to the mass of clay. The resulting suspension is sprayed with a nozzle and granulated in a counter-flow of hot gas at 250-400 ° C. Table. 1 shows the data on the mechanical strength of the granules obtained by the method. To obtain data on the filtering ability of the material, technological tests were carried out on an experimental test bench. The test bench consists of two filter columns with a diameter. 50 MT-i, 2000 mm high. One of the columns is loaded with materials, obtained by the proposed method, the other with materials obtained by a known method. In both columns, the grain size is the same and is 1.01, 2 mm, the loading height is 1000 mm. Water filtration is carried out in top-down direction. The filtration rate is kept constant at 6.0 m / h. The quality of water supplied to filtration is characterized by the following indicators: suspended solids 10 mg / l, chromaticity 40 degrees, pH 7.1. Immediately before serving, the coagulant, aluminum sulfate, in an amount of 25 mg / l is added to the initial water in the filtration systems. The criterion of the filtering ability of materials is the amount of water purified by the filter cycle. The duration of the filter cycle of each column makes it harder for a period of time during which the filter produces water that meets the requirements, namely chromaticity 20 degrees, turbidity 1.5 mg / l, pH 7.0. The results of technological tests are presented in Table. 2, The results of technological tests of the filtering ability materiya3i: / 649694

fishing with various additives and their coli-duration of the filter cycle, and

and at various temperatures, therefore, the amount of purified

granulations are presented in table. 3. for the filter cycle of water. In addition, predHak follows from the table. 2 and 3, the method simplifies the process.

use of filtering water for water purification; 5 receiving filler material for

materials obtained from the proposal to eliminate the energy-intensive stage

by increasing the burn rate.

Table 1

Orthophosphorus Technological Performance Indicators

The proposed method

The filter material with the addition of orthophosphoric acid in the amount of 16.5% at the granulation temperature

. Initial pressure loss in loading, m

Growth rate of head loss, m / h of filter materials

Known method

Filtering material with the addition of dolomitic limestone

0.36

0.075

Technological performance

Technological characteristics

The proposed method

Filtering material with the addition of orthophosphoric acid in the amount of I6j, 5% by PjjOy at the temperature of granulation

Continue filtering 14 cycles of 5 h

The quality of the filtrate during the filter cycle;

chromaticity

hail

turbidity,

mg / l

Eye count

Shchennoy ZeCh filter cycle water, l

Continuation of table 2 filter materials

Known method

Filtering material with the addition of dolomitated limestone

eleven

13-20

1.0-1.5

141

Claims (2)

1. METHOD OF OBTAINING GRANULATED FILTER MATERIAL for water purification, including the introduction of an additive into the clay suspension with its subsequent granulation at 250-400 ° C, characterized in that, in order to simplify the process and increase the filtration capacity of the material, orthophosphoric acid, hexametaphosphate . sodium or monosodium phosphate. 2. The method according to claim 1, characterized in that the additive is introduced in the amount of 16-33 wt. X in terms of P ₂ 0, relative to the mass of clay. (264969