Generally, we only know that gypsum powder is used in construction industry, but seldom know that gypsum powder plays a very important role in agricultural production. The original application scope of gypsum powder is so wide. Hongtai gypsum introduces three major applications of gypsum powder in agriculture.
1. Improve the soil, adjust the pH value, suitable for the improvement of saline-alkali land and red soil.
2. Edible fungi can be used as calcium and sulfur compound mineral fertilizer to regulate the pH value of the medium.
3. Compound mineral feed additives for livestock and poultry feed.
In production, because of the inherent variability of gypsum mould, the quality of gypsum mould is difficult to control steadily. One aspect of this change is the influence of water ratio and concentration of gypsum on the performance of gypsum model. Generally speaking, the paste has small water ratio, high porosity, low strength and short service life. The paste has high water ratio, low porosity, high strength and long service life. The change of gypsum water ratio is related to the aging time of gypsum powder, especially the difference between newly fired gypsum powder and mature gypsum powder. The newly fired gypsum powder has no deterioration, homogenization, high temperature, strong surface activity and high water mixing capacity. When used immediately, many bubbles will be formed on the surface of the model, and the overall strength is low. Generally, the newly fried gypsum powder needs to be stored for two weeks before it is applied.
The research results of foreign scholars show that the moisture content and rheological properties of gypsum powder vary with the storage time, which is due to the aging process of gypsum in the air. The process can be divided into two stages: one is the rapid hydration of soluble anhydrous gypsum (anhydrous gypsum) to form hemihydrate gypsum; the absorption rate of water by hemihydrate gypsum is very slow, so that the crystal transformation is completed, and the mixed water volume gradually decreases. When the relative humidity of air is low, the water content of gypsum powder can reach a certain level after the reaction of water-soluble anhydrite. If the relative humidity of air is relatively high and the hydration reaction continues, dihydrate gypsum can be formed, which has adverse effects on the quality and production stability control of gypsum powder. Generally speaking, gypsum powder enterprises store and use its performance to test, so as to judge the demand of gypsum powder mould, and adjust the parameters of the production model according to the performance index of gypsum powder to meet the requirements of the mould.