RU1781233C - Method for production of cations - Google Patents

Abstract

Usage: in hydrometallurgy, water treatment, in the treatment of wastewater, in the production of biological products. SUMMARY OF THE INVENTION: granular copolymerization of styrene, acrylonitrile and a low concentration fraction of divinylbenzene, washing the copolymer, dehydration with a motherboard sulfonation solution with a sulfur concentration of 50-85% and sulfonation. 1 s p file, 1 tab.

Description

The invention relates to methods for producing styrene-based cation exchanger, which can be used in hydrometallurgy, water treatment in the treatment of waste water, in the production of biological products, as a catalyst in organic synthesis, etc.

Known methods for producing cation exchanger. comprising treating an air-dry styrene copolymer with sulfuric acid at a temperature of 60-150 ° C.

The disadvantages of these methods of producing cation exchange resin are:

-the need for drying the obtained styrene copolymer in special units:

- neutralization of air outflow (coolant) from aromatic substances (benzene, toluene, etc.);

-the need to use as a swelling agent a styrene copolymer of halogenated hydrocarbons. which are industrial ladies (dichloroethane);

-the need for distillation and regeneration of the swelling agent, which complicates and increases the cost of cation exchanger synthesis technology

The technological solution closest to the proposed method is a method for producing sulfocationionite by introducing a third component, an aliphatic monomer, for example acrylonitrile, into the styrene carcass, and using a technical and light fraction of divicylbenzene as a cross-agent, which eliminates the stage of preliminary swelling of the copolymer.

The disadvantages of this method should still include:

-the need for drying the resulting wet copolymer in special units;

- neutralization of the air flow from aromatic substances;

In addition, in the process of thermal neutralization of the copolymer, granules containing a fraction of the limiting aromatic substances (benzene, ethylbenzene toluene, etc.) partially lose them with VJ 00

io

SLE SLE

coolant flow, which is reflected in the reticulation, uniformity of the structure of the polymer skeleton and the availability of the penetration of the sulfonating agent to its active centers.

The aim of the proposed solution is to reduce production operations, increase the capacity and strength of cation exchange resin. This goal is achieved in that the wet copolymer is dehydrated by treatment with a mother sulfonation solution. According to the proposed method, the reduction of production operations occurs due to the exclusion of the drying process of the wet solimer in dry aggregates. The drying process of copolymers (polymeric materials) is always associated with a change in the structure of the copolymer. The proposed method of dehydration of the wet copolymea allows preserving the elasticity of the granules prior to the sulfonation reaction, which explains the increase in the capacity and strength of cation exchange resin in comparison with the prototype. The dehydration of the blissful copolymer is carried out with a mother liquor of sulfonation of 50-85% sulfuric acid for 10-60 minutes. The upper limit of the concentration of the mother liquor (85%) is due to the sulfonation conditions of the copolymer with technical sulfuric acid. The lower limit of sulfonation mother liquor concentrations (50%) is due to the copolymer dewatering quality. A decrease in time of less than 10 minutes, even with a high concentration of the mother liquor, increases the likelihood of moisture leakage and reduces the exchange capacity of the cation exchanger. An increase in the contact time of the wet copolymer and the mother liquor for more than 60 minutes does not improve its quality.

The invention is carried out as follows: granular copolymerization of eninyl monomers is carried out at 70-90 ° C in an aqueous medium using peroxide initiators (benzoyl peroxide, etc.) and emulsion stabilizers (starch, polyacrylamide, etc.). Granules wet copolymer (5-17% H20) is discharged into a column with drainage, washed with water and treated with a mother sulfonation solution (50-85% according to H2SCM). In this case, the copolymer moisture is reduced to 0.3-0.9%. and the concentration of the mother liquor drops by 5-10%. Then the hydrated mother liquor is drained and the granules are transferred to a reactor, to which 5-6 times (weight) the amount of technical 93% sulfuric acid is added. The sulfonation reaction is carried out at 90-115 ° C for 6-8 hours

After the agitation time has elapsed, the reaction mass is cooled, part of the mother liquor (approximately 50%) is separated, and the remaining mass is subjected to smooth hydration. The selected mother liquor is used to dehydrate subsequent batches of the copolymer. The invention is illustrated by the following examples.

Example 1. To 320 ml of water containing 3.2 g of potato starch was added a polymerization mixture consisting of 1.37 g (EreTsisibenzoyl, 95 g of styrene, 12.12 g of technical divinylbenzene (52.1% , DVB, 32.82% unsaturated), 6.53 g of acrylonitrile and 23.6 g of the light fraction of DVB (7.8% DVB, 32.1% of unsaturated aromatic hydrocarbons, 60.1% of saturated aromatic hydrocarbons). loaded at 50 ° C, dispersed to obtain droplets of a certain size (0.2 1.6 mm), heated, gradually raising the temperature to 90 ° C for 4 hours, and kept at 90 ° C for 2 hours. The mass was cooled, the granules were separated from the batch solution and washed with water. The wet granules (10.2% H20) were treated with a mother sulfonation solution containing 74% H2S04 for 35 minutes. The hydrated mother liquor (63% H2S04) was squeezed, and the copolymer beads with a residual moisture content of 0.4% were transferred to a reactor flask, to which 500 ml of technical sulfuric acid was added (93% H2S04. The mixture was agitated at 110 ° C for 6 hours. At the end of the sulfonation process, the reaction mixture is cooled, 250 ml of the mother liquor are separated, and the remaining mass, with vigorous cooling and stirring, is slowly diluted with water to 10% solution concentration in sulfuric acid. The granules are then separated from the solution and washed with water to pH 3-4. The resulting sulfocationite has the following characteristics:

P63-1.92NЈL1E. ml

GMP-98% -

VyA - 2.6 cm3 / g

Example 2. To 320 ml of water containing 3.2 g of potato starch, a polymerization mixture consisting of 0.8 g of benzoyl peroxide, 48.9 g of styrene, 8.3 f of technical divinylbenzene (68.13% DVB, 24.0) was added. % unsaturated) and 51.5 g of alkyl gasoline. The mixture was loaded at 50 ° C, dispersed to obtain droplets of a certain size (0.2-1.6 mm), heated, gradually raising the temperature to 80 ° C, for 3 hours and kept at this temperature for 2 hours. The reaction mixture is cooled, the granules are separated from the mother liquor and washed with water. The loose granules (17.1% H20) are treated with a mother sulfonation solution containing 68% H2S04 for 60 minutes. The flooded mother liquor (59% Nab) was squeezed out and the copolymer granules with a residual moisture content of 0.9% were transferred to a reactor flask, to which 500 ml of sulfuric acid (93% H2SO4) was added. The mixture was agitated at 105 ° C for 8 hours. At the end of the sulfonation process, the reaction mixture is cooled, 250 ml of the sulfonation mother liquor are separated, and the remaining diluted with water to a concentration of 15% sulfuric acid. Then the granules are separated from the solution and washed with water to pH 3-4.

The resulting sulfation has the following characteristics:

poet t.3 g

 GMP-98% Uud - 3.5 cm3 / g

0

5

0

Examples of the method for producing cation exchanger and the method for preparing the prototype are shown in the table.

F .. about r m u l a from about b and t and

1. The method of producing cation exchange resin by the granular copolymerization of styrene, acryl nitrile and a low concentrated fraction of divinyl benzene, washing the copolymer obtained, dehydration, sulfuric acid sulfonation and separation of the sulfonation mother liquor, and so on, since In order to reduce production operations, increase the capacity and mechanical strength of the cation exchange resin, the copolymer is dehydrated by treating it with a mother liquor of sulfonation of 50-85% concentration in sulfuric acid.

2, the Method according to years. 1, characterized in that the dehydration with a mother sulfonation solution is carried out at normal temperature for 10-60 minutes.