Calcium lignosulfonate water reducing agent is extracted from pulp waste liquid. The products are divided into two categories, namely calcium salt and sodium salt of lignosulfonate, the latter obtained from the processing of the former. In the manufacture of rayon or in the paper industry, when the wood is cooked at high temperature and high pressure, sulfite is added to separate the cellulose and non-fiber in the wood,and the obtained cellulose is the raw material of rayon,artificial wool, paper, etc. The non-cellulose dissolved in the solution was dominated by lignosulfonates with a small amount of sugar.
This solution is called pulp waste. After the alcohol and yeast are extracted from the waste liquid, the remaining substances are then spray-dried with hot air to form a brown powder, which is calcium lignosulfonate powder. The content of calcium lignosulfonate is about 45-50%, reducing substances The content is less than 12%.
At present, the market demand for calcium lignosulphonate and its modified products is gradually increasing, making the analysis and utilization of lignin and obtaining corresponding economic benefits from it gradually become a reality. Therefore, in the future, we will strengthen the research and development of new methods, new technologies and new processes in the reform of calcium lignosulphonate to develop lignin products with large market demand, good performance and good economic benefits, and accelerate the large-scale utilization of lignin. It will promote the full utilization of natural renewable resources and the basic management of pulp and paper waste liquid purification and discharge.
Lignosulfonate water reducing agent has been used in my country for 40-50 years. However, due to its low water reduction rate, slow setting, small increase in compressive strength of concrete, and low early strength, its application in concrete is limited. It also affects the improvement of its own value. At present, calcium lignosulfonate water reducing agent is still mainly used in summer concrete construction as concrete retarder. The world can produce 30 million tons of industrial lignin every year. At present, only about 6% of industrial lignin in my country is used, and most of the rest are discharged into rivers as waste. Seriously pollute the environment.
Activating and modifying calcium lignosulfonate and compounding it with naphthalene-based superplasticizer can formulate high-efficiency water-reducing conservancy, and overcome the shortcomings of calcium lignosulfonate's retardation and low early strength, and greatly reduce the naphthalene-based superplasticizer. cost and expand the application scope of wood calcium.
Post time: Feb-07-2022
