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Method for preparing naphthalene series water reducing agent

The technology of naphthalene-based water-reducing agent and naphthalene sulfonic acid is applied in the field of preparation of concrete admixtures, which can solve the problems of labor, waste of energy-consuming raw materials, pollution of the environment by calcium sulfate waste residue, and quality of sodium sulfate affecting the quality, so as to reduce the cost of raw materials, The effect of factors that improve production and social benefits and reduce environmental pollution

Active Publication Date: 2013-04-24
ZHEJIANG JISHENG CHEM BUILDING MATERIALS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The main defect of this production process is: there is a lot of excess sulfuric acid in the production process, and only using liquid caustic soda to neutralize will cause the sodium sulfate content in the final product to exceed the standard and affect the quality. It is necessary to add calcium hydroxide to further neutralize the excess sulfuric acid. As a result, the generation of calcium sulfate waste residue pollutes the environment, and the products wrapped in the precipitation process and the product entrained by the filter residue will reduce the production efficiency. In addition, to remove the calcium sulfate waste residue, pressure filtration must be carried out, resulting in labor, energy consumption, and waste of raw materials, which is not conducive to energy saving and consumption reduction.
In addition, there are industrial naphthalene residues in the product, which has adverse effects on the environment

Method used

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  • Method for preparing naphthalene series water reducing agent
  • Method for preparing naphthalene series water reducing agent
  • Method for preparing naphthalene series water reducing agent

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] like figure 1 As shown in the process flow, the production process of high-concentration naphthalene-based water reducer mainly includes steps such as melting naphthalene, sulfonation reaction, steam hydrolysis to remove naphthalene, recovery and application of naphthalene, condensation reaction, and neutralization reaction.

[0027] The specific method is as follows:

[0028] (1) Melting naphthalene. Put 3000kg (23.4kmol) of industrial naphthalene in a melting tank and melt it to obtain molten industrial naphthalene at 100°C.

[0029] (2) Sulfonation reaction. The liquid industrial naphthalene of above-mentioned step (1) gained molten state is squeezed in the sulfonation kettle by metering pump, simultaneously 2000Kg 98% concentrated sulfuric acid (20.4kmol) is squeezed into sulfuric acid head tank (industrial naphthalene: sulfuric acid mol ratio=1.15: 1 ), the temperature in the kettle was raised to 140°C, and the metered concentrated sulfuric acid was evenly added...

Embodiment 2

[0037] With the 460Kg industrial naphthalene recovered in 2560Kg industrial naphthalene and embodiment 1, the 37% formaldehyde consumption in the step (5) is changed into 1550Kg, and the liquid high-concentration type naphthalene series high-efficiency water reducing agent of step (6) will neutralize the reaction to finish gained The finished product is directly sent to the spray tower for spray drying to obtain the finished solid high-concentration naphthalene-based high-efficiency superplasticizer, and other steps remain unchanged.

[0038] (1) Melted naphthalene

[0039] Industrial naphthalene 2560kg and naphthalene 460kg reclaimed according to the method described in example 1 are concentrated in melting tank and melted, and liquid industrial naphthalene (23.6kmol) of molten state is obtained at 100 ℃;

[0040] (2) Sulfonation reaction:

[0041]The liquid industrial naphthalene of the molten state obtained in the above step (1) is squeezed into the sulfonation kettle by a...

Embodiment 3

[0050] Embodiment 3 (comparative example):

[0051] Melt 2400Kg (18.75kmol) industrial naphthalene in the naphthalene melting kettle, put the liquid industrial naphthalene in the molten state into the sulfonation kettle, add 2659Kg (26.59kmol) concentrated sulfuric acid to carry out sulfonation at 120~160°C (naphthalene: concentrated sulfuric acid=1 : 1.4), sulfonated for about 3 hours, poured into the hydrolysis kettle to cool down to 120°C, added 1100Kg tap water to the kettle for hydrolysis reaction for 45-60min, cooled down after hydrolysis, poured into the condensation kettle, and added dropwise 1400Kg of 37% formaldehyde at about 80°C (17.27kmol) to carry out the condensation reaction, the dropwise addition is completed at 100°C and the condensation reaction is about 5 to 6 hours. After cooling down, put 525Kg of calcium hydroxide into the neutralization tank and stir for one hour, then add 3000Kg of liquid sodium hydroxide (concentration 30%) to adjust the pH value to 7...

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Abstract

The invention provides a method for preparing a naphthalene series water reducing agent. The method comprises the following steps of naphthalene fusion, sulphonation reaction, steam hydrolysis naphthalene removal, recovery and reuse of naphthalene, condensation reaction and neutral reaction. Compared with the conventional production technology, the process of the invention has the advantages that: the consumption of sulfuric acid is reduced by adjusting a material charging ratio of sulfuric acid to material naphthalene at the step of sulphonation reaction; the step of the recovery and reuse of naphthalene is added, so that the raw materials are fully utilized; and in the following step of neutral reaction, only a small amount of alkali solution is added and the addition of calcium hydroxide is unnecessary, so that the filter step is eliminated, and deposition loss and entrainment loss of the products are avoided.

Description

(1) Technical field [0001] The invention relates to a method for preparing a concrete admixture, in particular to a method for preparing a high-concentration naphthalene-based water reducer or a homologous dispersant thereof. (2) Background technology [0002] Due to the needs of industrial development, people have put forward higher and higher requirements for the performance of concrete, and a necessary condition for realizing the high performance of concrete is the use of high-efficiency water reducing agent, which can not only improve construction conditions, but also improve the compressive and flexural resistance of concrete Strength, but also can enhance the performance of concrete such as frost resistance and impermeability, is considered to be the fifth component necessary for concrete. At present, most of the high-efficiency water reducers used in China are naphthalene-based water reducers. However, in its production process, due to the use of excessive concentrat...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C309/36C07C303/22C08G16/02C04B24/22C04B103/30
Inventor 金瑞浩李应斌
Owner ZHEJIANG JISHENG CHEM BUILDING MATERIALS
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