SU947086A1 - Process for purifying effluents from isoprene rubber production - Google Patents

Description

(54) METHOD FOR CLEANING WASTE WATER OF ISOPRENE RUBBER PRODUCTION

one

The invention relates to the production of synthetic isoprene rubber, half an hour by polymerizing isoprene in a solution of isopentane, in particular to the treatment of waste water at the stage of separation of rubber from a solution by the method of water degassing.

The closest in technical essence to the present invention is a sewage treatment method in the production of isoprene rubber, according to which the water discharged from the stage of rubber separation is directed to the chemical sewage system and further to the sewage treatment plant, where it is subjected to biological treatment, and the water containing hydrocarbons is sent to a final stripping l.

However, according to a known method at a sewage treatment plant, water of different quality and containing various contaminants is subjected to joint purification, therefore water after sewage treatment plants is unsuitable for production purposes, and is discharged into water bodies.

Thus, the method does not provide for local treatment (at the stage of rubber production) of wastewater from the agglomerator and creamer rubber, as a result of which water of rather high quality in terms of its salt composition is discharged into the chemical sewage system.

The purpose of the invention is the degree of purification and the possibility of repeated use of water directly in production.

This goal is achieved by acidifying the waste water to pH 5-7 before distilling the hydrocarbons and treating it with a rubber solution, feeding 1 M for degassing.

Preferably, the waste water after distillation of the hydrocarbons is directed to desalting.

The method is described as follows.

in a way.

Water containing anti-agglomeration and fine crumb of rubber, separated from rubber extraction, is mixed in a 39 1 tack mixer with a solution of polyophenol in isopentane, thus extracting an ant agpomer and rubber of water. In order to prevent the formation of a water solution, the solution is quenched, the water is poured to pH 5-7 before being fed into the mixer. In the mixer, the emulsion is sent to a separation tank, where, due to the difference in densities, the solution of ihshkzoprene is separated from water. The solution of popiisoprene is withdrawn from the upper part of the separation vessel and is fed to the degassing agent. The water purified from the anti-agglomerator and fine crumbs of rubber is removed from the lower part of the separating tank and sent to a stripping column, where the organic substances that are carried away with water after contact with the polyisoprene solution are distilled off. The aqueous part of the condensate from the degassing vapors is also directed to the stripping of volatile organic substances. The water after stripping, which is close in quality to a portion of the shocked softened deoxygenated water, is sent to the pulping equipment or used for process nurses, for example, for stretching the polymer. Example. 1 l of waste water from the production of isoprene rubber from the stage of its separation from aqueous pulp is placed in a mixer, acidified with hydrochloric acid to pH 5, 250 ml of an 11.6% strength solution of trisprene in isopentane are added and mixed for 10 minutes . After stirring, the water is separated and stripped from the organic substances and then analyzed. The results of the analysis are as follows. Total hardness, mEq / l 0.8

Antiagglomerator content

mg / lNo

No e Carbonate hardness, mg-q / l 0.3 Alkalinity, total, mg-okv / p 0.3 Dioxide content of carbon, mg / l 2,0 Dissolved oxygen content, mg / l 0.29 Oxygen oxidation, mg / l 7, 0 The content of suspended substances, mg / l2,4 The content of anti-agglomerator (calcium stearate), mg / l1.1 The above data show that the proposed method allows you to purify water from small crumbs of rubber (1 suspended substances) and anti-agglomerator, and the quality is very narrow meets the requirements for partially depleted de-oxygenated water. At the same time, on a ton of rubber produced, about 4 kg of rubber are extracted from the water, which will save 400-500 tons of rubber per year only on one of the enterprises of synthetic rubber. EXAMPLE 2. Sewage water is sutured according to the following method: acidified with phosphoric acid (1% aqueous solution) to a pH of 5-7, treated with a solution of polyisoprene, and the hydrocarbons are distilled off and desalted. The quality indicators of purified water are given in comparison with the actual quality indicators of partially softened deoxygenated water used in production.

Froze 300 ml of waste water and a 1 p solution of iopoprene in iopentane, selected in the production of ioprene rubber, are placed in a mixture and mixed for 5 minutes until an emulsion is obtained. After repacking

Water experience

It can be seen from the above data that it is unacceptable to maintain a pH greater than 7 during the purification process, since this greatly increases the water resistance of the emulsion — a solution of polysoprene and increases the risk of entrainment of the polymer solution with water. Lowering the pH to less than 5 is impractical, since the separation time decreases slightly.

Claims (2)

1. Wastewater treatment method for the production of isoprene rubber, producing a time separation of the emulsion. The experiments are repeated as many times at different pH values. The pH is regulated by the addition of hydrochloric acid or a solution of sodium alkali. Time delamination, min 69 6.7 5.5 polymerization of isoprene in a solution of isopentane and allocated by water degassing in the presence of an anti-agglomerator of rubber crumb, including the distillation of hydrocarbons and the recovery of fine crumbs of rubber, characterized in that, in order to increase the degree of purification and reuse of water, The pH is 5 to 7 and treated with the rubber solution supplied for degassing. 2. The method according to claim 1, wherein the waste water is sent to desalting after the distillation of the hydrocarbons. Sources of information, taken into account during the examination 1. Kirpichnikov P. A. and others. - Album of technological schemes of the main production of the synthetic rubber industry. L., Himi, 1976, p. 63.