Process for preparing modified naphthalene series water reducing agent

Abstract

The invention discloses a method for preparing a modified naphthalene water reducing agent, which comprises the following steps: A, adding industrial naphthalene to a glass lining reaction kettle to be melted, and adding industrial concentrated sulfuric acid to the reaction kettle; B, sampling and measuring the acid number to determine the water quantity to be added to a hydrolysis reaction; C, adding industrial formaldehyde to the mixture to perform reaction so as to obtain a naphthalene sulfonic acid formaldehyde condensation compound; D, adding pulping waste liquor and water to the mixture respectively from the top and the middle part of a formaldehyde absorption tower while adding the formaldehyde to the mixture, using a pump to perform circulating spraying on the waste liquor and the water on the upper section and the lower section of the adsorption tower respectively, and adding the waste gas generated by a condensation reaction to the lower part of the formaldehyde absorption tower so as to have a counter current contact with the water and obtain a waste liquor containing the formaldehyde; E, adding a diluted formaldehyde solution to a condensation reaction material, reducing the viscosity of the material and reclaiming the formaldehyde; F, delivering the formaldehyde pulping waste liquor to a waste liquor reaction kettle to perform sulphonation and condensation reactions; and G, preparing the modified naphthalene water reducing agent. The method achieves the zero emission of the formaldehyde with less usage; the water reducing rate of the water reducing agent is improved by 3 to 8 percent compared with the conventional product, and the utilization of an environmental pollutant pulping waste liquor is achieved.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a preparation method of a modified naphthalene-based water reducer, which is applicable to the preparation process of concrete admixtures, and is also applicable to the preparation process of dispersants and oilfield chemicals. Background technique [0002] Concrete is the most widely used inorganic material in the world. It is usually made of sand, stone, cement, mineral admixtures (fly ash, mineral powder, etc.) and admixtures, mixed with water, and hardened. The function of concrete admixture is to add to concrete to improve the workability, impermeability, frost resistance and other properties of concrete. Common admixtures include water reducing agent, antifreeze agent, early strength agent, expansion agent, etc. Water reducing agent is the most widely used concrete admixture in the largest amount. [0003] The function of water reducing agent is to s...

AI Technical Summary

Problems solved by technology

At present, some paper mills around the world use alkali recovery boilers to incinerate concentrated pulping waste liquid to avoid waste liquid discharge and pollute the environment, but there are still problems of concentration, high recycling cos

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