A paper-making black liquor modified sulfamate high-efficiency water reducer and its preparation method

Abstract

The invention discloses a papermaking black liquor modified sulfamate high efficiency water reducer. The high efficiency water reducer is prepared from, by weight, 130-140 parts of sodium sulfanilate, 30-60 parts of a papermaking black liquor, 12-30 parts of sulfur dioxide, 50-70 parts of phenol, 150-180 parts of formaldehyde, 15-30 parts of a 30% liquid alkali, 9-13 parts of urea, and 200-360 parts of water. A preparation method of the high efficiency water reducer comprises the following steps: sulfonating the papermaking black liquor with sulfur dioxide, adding the sulfonated papermaking black liquor to a sodium sulfanilate, urea and phenol mixed alkaline solution, adding formaldehyde in a dropwise manner, and carrying out a condensation reaction to prepare the papermaking black liquor modified sulfamate high efficiency water reducer. The high efficiency water reducer prepared in the invention has the advantages of obvious reduction of the slump loss and the water segregation phenomenon of concrete, increase of the slump retaining property, workability improvement, low production cost, environmental pollution reduction, realization of full utilization of the papermaking black liquor, and reduction of the recycling cost.

Description

technical field [0001] The invention relates to the field of concrete materials, in particular to a paper-making black liquor modified sulfamate high-efficiency water reducer and a preparation method thereof. Background technique [0002] Sulfamic acid-based high-efficiency water reducers belong to anionic surfactants, which were developed and utilized in Japan in the late 1980s. At present, the commonly used sulfamic acid-based water reducers in China are mainly condensation products of sulfamate, phenol and formaldehyde. This type of water reducing agent has the characteristics of high water reducing rate and high slump retention, and is a kind of high-efficiency water reducing agent with excellent performance. However, it still has the following problems in its production and application: 1. The main raw material p-aminobenzenesulfonic acid ( (sodium p-aminobenzenesulfonate) and phenol are on the high side, and the production cost is high; 2. phenol and formaldehyde are ...

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Problems solved by technology

This type of water reducing agent has the characteristics of high water reducing rate and high slump retention, and is a kind of high-efficiency water reducing agent with excellent performance. However, it still has the following problems in its production and application: 1. The main raw material p-aminobenzenesulfonic acid ( (sodium p-aminobenzenesulfonate) and phenol are on the high side, and the production cost is high; 2. phenol and formaldehyde are volatile and toxic, and are likely to cause pollution to the environment; 3. when used in concrete, they are more sensitive to the dosage. The amount of phenol is low, and the concrete slump is small. If the amount is large, it is easy to make the concrete bleed, and the workability is poor, resulting in difficulties in construction; 4. The domestic production of phenol is far less than the demand for phenol, and the trend is increasing. import demand is increasing

At present, most of the methods used to solve the above problems are compounding methods, and there are few related reports on improving the synthesis of water reducing agents.

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