CN1143653A - Method for recovering waste polystyrene plastics - Google Patents

Abstract

A method for recovering waste or used polystyrene plastics includes dissolving it in solvent such as ethyl acetate to obtain gel material, decolouring it, and distillation to remove solvent, and features low cost.

Description

Reclaim the method for waste and old polystyrene plastics

The present invention relates to a kind of method that reclaims waste and old polystyrene plastics, specifically, the present invention relates to a kind ofly make the waste and old polystyrol gelation by suitable solvent, again through decolouring, removing desolvates waits the method for poly-recovery of step waste and old polystyrol.

At present, all face the various plastic refuse problem of environment pollution caused of improvement in the world wide.In these plastic refuses, waste and old polystyrol (comprising foaming product and common goods) occupies suitable vast scale, and for example various depleted electrical packages are seen everywhere with cushioning material, lagging material, especially disposable tableware etc.There are some to reclaim the method for waste and old polystyrol in the prior art, utilize heat energy as direct burning.As the stopping composition of preparation sound insulation, lagging material, be used to prepare binding agent etc. after the dissolving after the Mechanical Crushing, these methods fail to solve the governing problem of waste and old polystyrol, the collection of particularly a large amount of foam material wastes, the problem of transportation.Because polystyrene foamed plastics proportion is very little, bulk density has only the traffic capacity of 0.01 to 0.02, one truck extremely limited usually, and waste distribution region is very wide.Therefore collection and trucking costs are difficult to bear.In addition, though also useful solvent poly styrene wastes is dissolved, preparation coating etc., treatment capacity is very limited, and lysate handles without decolouring, the poor product quality that makes, its purposes is restricted.

The objective of the invention is to overcome the above-mentioned problems in the prior art, a kind of method of both economical suitable recovery waste and old polystyrol is provided.

By on the spot waste and old polystyrol being made the gel material with suitable solvent, not only saved man-hour among the present invention, and solved the little problem of traffic capacity, greatly saved cost.Among the present invention,, make the polystyrene non-variegation of recovery, solved product quality problem also by processing that the gel material is decoloured.

The solvent that uses among the present invention comprises toluene, benzene, toluene, N-BUTYL ACETATE.Vinyl acetic monomers etc., wherein ethanol acetate is preferred.

The discoloring agent that uses among the present invention is selected from silica gel, activated alumina, silicon bath soil, clay, gac etc. or its mixture.

The concrete steps of the inventive method are:

1, gelation

With waste and old polystyrol on the spot after the fragmentation, drop into and fill in the container of above-mentioned solvent, until sticking useless reach 2000 centipoises till, the sealing as ready;

2, decolouring

The concentration that will go on foot the material that obtains in poly-1 with described solvent transfers to 10～30% (weight percents), and adds the 2g discoloring agent by every kilogram of material, stirs, seal again 24 hours standby;

3, filter

The material that obtains in the step 2 is imported in the pressure-filtering tank, at 0.1～0.4MP _aCondition is carried out press filtration, and the gained clear filtrate is carried out secondary filtration again, and wherein filter cake is as the fuel of heating stove.

4, desolventize

The filtrate that obtains in the step 3 is carried out vacuum distilling, and vacuum tightness improved 7mmHg in per 10 minutes, and Heating temperature is 50～95 ℃, and vacuum tightness 〉=720mmHg during terminal point, heat-insulation pressure keeping stopped heating, emptying, discharging after 1 hour.

Because of vacuum pump with making pump oil thinning in a large amount of organic gas suction pumps, cause breaking of vacuum, and influence is produced.So, add the one-level absorption unit again, absorb organic gas in a large number, guarantee ordinary production, specifically with polystyrene foamed as filler, the absorption unit of packing into.

5, pulverize granulation.

With the polystyrene that the inventive method reclaims, alternative original polystyrene material prepares various goods.

Claims (4)

1, a kind of method that reclaims waste and old polystyrene plastics comprises:

(1) gelation:

With waste and old polystyrol on the spot after the fragmentation, drop into and fill in the molten device of solvent, reach 2000 centipoises up to viscosity, the sealing as ready.

(2) decolouring:

With described solvent the material concentration that obtains in the step 1 is transferred to 10～30% (weight percents), by every Kg discoloring agent, stir again, seal 24 hours again;

(3) filter:

To carry out press filtration in the material importing press filtration cylinder that obtain in the step 2, press filtration pressure is 0.1～0.4MP _a, and with gained filtrate secondary filtration;

(4) desolventize:

Carry out vacuum distilling with obtaining filtrate in the step (3), vacuum tightness improved 7mmHg in per 10 minutes, and Heating temperature is 50～95 ℃, and vacuum tightness 〉=720mmHg during terminal point, heat-insulation pressure keeping stopped heating, emptying, discharging after 1 hour;

(5) pulverize granulation.

2, method according to claim 1, wherein said solvent is selected from toluene, benzene, dimethylbenzene, vinyl acetic monomer, acetic acid fourth vinegar.

3, method according to claim 1, wherein said discoloring agent is selected from silica gel, activated alumina, silicon bath soil, clay, gac or its mixture

4, according to the described method of claim 2, wherein said solvent is selected from vinyl acetic monomer.