CN108249804B

CN108249804B - Concentration method of ester polycarboxylate superplasticizer

Info

Publication number: CN108249804B
Application number: CN201711438049.5A
Authority: CN
Inventors: 傅雁; 李国云; 虞亚丽
Original assignee: Suzhou Fuclear Technology Co ltd
Current assignee: Suzhou Fuclear Technology Co ltd
Priority date: 2017-12-26
Filing date: 2017-12-26
Publication date: 2020-10-09
Anticipated expiration: 2037-12-26
Also published as: CN108249804A

Abstract

The invention discloses a concentration method of an ester polycarboxylate superplasticizer, which is characterized in that in the process of producing the polycarboxylate superplasticizer, after a polymer polymerization process is finished, a water-containing system of a polymer is left in a reaction kettle for heat preservation and standing for settlement, the polymer is separated from the water-containing system and precipitated at the lower part of a container under the condition of not reducing the temperature, then the polymer at the lower layer is separated from water by a liquid separation method, and cooling is carried out after the separation is finished, so that the concentrated polycarboxylate polymer is obtained. After the reaction is finished, the invention does not carry out container conversion, and carries out sedimentation separation on the premise of no stirring and no temperature reduction, thereby ensuring the concentration effect; meanwhile, other substances are not added, the product treatment is not influenced, and the energy consumption is low because additional temperature rise is not needed, so that the method is a low-cost and environment-friendly concentration method.

Description

Concentration method of ester polycarboxylate superplasticizer

Technical Field

The invention relates to a concrete admixture, in particular to a concentration method of an ester polycarboxylate superplasticizer.

Background

The concentration of the ester polycarboxylate superplasticizer sold in the market at present is generally about 20%, and the product performance of the ester polycarboxylate superplasticizer synthesized by the concentration is the best. However, in order to reduce the cost of long-distance transportation and the cost of preparing powder, concentration is required, and the cost of conventional evaporation concentration is high.

Chinese patent CN1844021A discloses a concentration method in the preparation of a polycarboxylic acid water reducing agent, which comprises the following steps: in the process of producing the polycarboxylic acid water reducer high molecular polymer, after the synthesis process of the polymer is finished, the aqueous system of the polymer is directly transferred to an original reactor or other containers, the reactor is transferred to stand from the temperature after the synthesis process is finished, simultaneously, the temperature is reduced, the polymer is separated from the aqueous system and is precipitated at the lower part of the container, and then the precipitated polymer is separated from water by a physical method, so that a concentrated aqueous polycarboxylic acid polymer product is obtained. The method reduces the temperature while standing, so that part of the precipitated polymer is dissolved back into the upper layer of water, and the precipitation is incomplete.

In the 'method for concentrating polycarboxylic acid water reducing agent' disclosed in the Chinese patent application CN 102838316A: in the process of synthesizing the polycarboxylate water reducer, after the polymerization process is finished, cooling the synthesized polycarboxylate water reducer with the solid content of 35-60% to 30-70 ℃, adding inorganic salt, stirring and mixing for 15min, then standing and layering in a reaction kettle, wherein the lower layer is a clarified saline solution, the upper layer is a concentrated polycarboxylate water reducer aqueous solution, and a discharge valve at the bottom of a container is opened to discharge the saline solution at the lower layer to obtain the polycarboxylate water reducer with the solid content of 70-75%. In the method, the polycarboxylate superplasticizer is precipitated by an inorganic salt method, the cost is increased by salt, and the environmental problem is caused by the treatment of the salt solution at the lower layer.

Described in article "cloud point method concentration and purification of ester-based polycarboxylic acid water reducing agent" (member representative of Cone, 2010, China concrete admixture Association): the experiment utilizes the principle that nonionic surface active substances are precipitated at the cloud point, the polyester polycarboxylate superplasticizer solution is stirred and heated to be higher than the cloud point, then stirring is stopped, standing and layering are carried out, the upper-layer water phase is removed, and then the lower-layer polycarboxylate superplasticizer is cooled and neutralized to obtain the high-concentration refined ester polycarboxylate superplasticizer. The method is to stir and heat the solution of the polyester polycarboxylic acid water reducing agent to a temperature higher than the cloud point and then separate the solution, and obviously, the heating process is a process for increasing energy consumption.

Therefore, it is necessary to provide a new method for concentrating the ester polycarboxylate superplasticizer, so as to improve the efficiency and reduce the cost.

Disclosure of Invention

The invention aims to provide a method for concentrating an ester polycarboxylate superplasticizer, which realizes high-efficiency concentration of the superplasticizer on the premise of ensuring the product yield and reducing energy consumption.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows: a method for concentrating an ester polycarboxylate superplasticizer comprises the steps of retaining a water-containing system of a polymer in a reaction kettle for heat preservation and standing for settlement after a polymer polymerization process is completed in the process of producing the polycarboxylate superplasticizer, separating the polymer from the water-containing system without cooling, precipitating the polymer at the lower part of a container, separating the polymer at the lower layer from water by a liquid separation method, and cooling after separation is completed to obtain the concentrated polycarboxylate polymer.

Among the above-mentioned technical scheme, subside under the circumstances of not stirring, not cooling, guaranteed the effect of subsiding.

According to a further technical scheme, the separated and cooled polycarboxylic acid polymer is neutralized to form salt.

In a further technical scheme, the obtained salt of the polycarboxylic acid polymer is prepared into powder through spray drying.

The upper water layer after liquid separation is used as bottom water for next batch polymerization reaction.

In the preferable technical scheme, the standing and settling time is not less than 1 hour.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

1. after the reaction is finished, the invention does not carry out container conversion, and carries out sedimentation separation on the premise of no stirring and no temperature reduction, thereby ensuring the concentration effect; meanwhile, other substances are not added, the product treatment is not influenced, and the energy consumption is low because additional temperature rise is not needed, so that the method is a low-cost and environment-friendly concentration method.

2. The upper layer water after liquid separation is used as bottom water for next polymerization reaction, so that the recovery rate of the product can be improved, and water resources are saved.

Detailed Description

The invention is further described below with reference to the following examples:

example (b):

in the process of producing the ester polycarboxylic acid water reducing agent, after the polymerization process of the polymer is completed, the stirring of the reaction kettle is stopped, the temperature of the material is 70-100 ℃, the polymer can be gradually stood and settled in the reaction kettle, the polymer is separated from a water system and settled at the lower part of the container under the condition of not reducing the temperature, and the settled polymer is separated from water by a liquid separation method after 1 hour, so that the high-concentration polycarboxylic acid polymer is obtained. Cooling and neutralizing the lower-layer high-concentration polycarboxylic acid polymer subjected to liquid separation of the sediment to form salt, and further performing spray drying to prepare powder; the upper water was used as the bottom water for the next polymerization.

Comparative example:

in the process of producing the ester polycarboxylic acid water reducing agent, after the polymerization process of the polymer is finished, the stirring of the reaction kettle is stopped, the temperature of the materials is 70-100 ℃, the polymer can be gradually stood and settled in the reaction kettle, meanwhile, the jacket of the reaction kettle is opened with cooling water to reduce the temperature, the polymer is separated from a water system and also settled at the lower part of the container, and when the temperature of the materials is reduced to be below 60 ℃, the precipitated polymer is separated from water by a liquid separation method, so that the high-concentration polycarboxylic acid polymer is obtained.

The yields and properties of the high-concentration ester-based polycarboxylic acid polymers obtained in examples and comparative examples are shown in Table 1:

table 1:

as can be seen from Table 1, the yields of the examples are higher than those of the comparative examples, and the product properties are not degraded, so that the concentration process of the present invention achieves unexpected technical effects as compared with the comparative examples.

Claims

1. A method for concentrating an ester polycarboxylate superplasticizer comprises the steps of retaining a water-containing system of a polymer in a reaction kettle for heat preservation and standing for settlement after a polymer polymerization process is completed in the process of producing the polycarboxylate superplasticizer, separating the polymer from the water-containing system without cooling, precipitating the polymer at the lower part of a container, separating the polymer at the lower layer from water by a liquid separation method, and cooling after separation is completed to obtain the concentrated polycarboxylate polymer.

2. The method for concentrating the ester type polycarboxylate superplasticizer according to claim 1, wherein: and neutralizing the separated and cooled polycarboxylic acid polymer to form salt.

3. The method for concentrating the ester type polycarboxylate superplasticizer according to claim 2, wherein: the salt of the polycarboxylic acid polymer obtained is spray-dried to prepare a powder.

4. The method for concentrating the ester type polycarboxylate superplasticizer according to claim 1, wherein: the upper water layer after liquid separation is used as bottom water for next batch polymerization reaction.

5. The method for concentrating the ester type polycarboxylate superplasticizer according to claim 1, wherein: the standing and settling time is not less than 1 hour.