Alkali lignin modified sulfamate high-effective water reducer and preparation method thereof

Abstract

The invention discloses a preparation method of alkali lignin modified sulfamate highly effective water reducing agent, which includes the steps that: firstly, alkali lignin, phenol and water are evenly mixed, and an alkaline regulator is used to adjust the pH value of a reaction system to 8.0-10.0 and heat the temperature to 80-100 DEG C for half an hour to two hours; secondly, the pH value is adjusted to 9.0-11.0, and aminobenzene sulfonic acid sodium is added to react under the temperature of 60 to 80 degrees for half an hour to one hour; thirdly, the temperature is heated to 75-95 DEG C, and condensing agent is dropped. After that, the reaction continues for three to six hours and then the temperature is lowered. The obtained water reducing preparation, having low cost and small content of free formaldehyde and phenol, can improve the fluidity of concrete and compressive strength significantly. The preparation method is a simple technique without the discharge of three wastes in production.

Description

Alkali lignin modified sulfamate high-efficiency water reducer and preparation method thereof technical field The invention relates to a high-efficiency water reducer suitable for cement, concrete or mortar in construction engineering and a preparation method thereof, more specifically, a high-efficiency sulfamic acid salt prepared by modification using alkali lignin as raw material. Water reducing agent. Background technique With the continuous development of construction and engineering construction, the amount of concrete is increasing day by day. According to incomplete statistics, the world's annual output of cement exceeds 1.5 billion tons, which is equivalent to no less than 4.5 billion m3 of concrete, of which my country's concrete consumption is about 1.5 billion m3 . At present, the whole world starts from the speed, efficiency and cost of construction projects. The engineering structure and construction have continuously put forward new requirements for the perf...

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Problems solved by technology

However, there are three problems in the production and application of sulfamate high-efficiency water reducers, which affect its production and popularization and application: First, the main raw materials, sodium p-sulfanyl sulfonate and phenol, are petroleum industry products, which are non-renewable Resources and raw materials are expensive, and production costs are high; second, the water retention of concrete is not good during the application process, and the phenomenon of segregation and bleeding is serious, and even the slurry is hardened and separated from water

Due to the large bleeding of the water reducing agent, there are many bleeding channels in the concrete, and the structure is prone to cracks, which has an adverse effect on the durability of the concrete; third, the main raw materials for production are phenol and formaldehyde, which are volatile toxic substances, and the products are often Contains relatively high free phenol or formaldehyde, which will cause great pollution to the environment and bring harm to operators. In the existing production process research, it has not been used as the main monitoring index

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