What is the influence of gypsum calcination equipment on the performance of desulfurized building gypsum

Gypsum calcination equipment greatly interferes with the production characteristics of FGD building gypsum. The proper calcination equipment and processing technology should be used to produce FGD gypsum for different purposes. For the production of gypsum building materials such as various gypsum plasterboards and aerated blocks, rapid calcination equipment should be used, that is, the calcination method in which the temperature of raw materials is ＞ 180 ℃ and the raw materials remain in the furnace for several minutes or seconds.

This kind of calcination method is that the dihydrate gypsum is quickly dehydrated after being heated, and quickly converted into hemihydrate or anhydrite III. Because of the high temperature of raw materials, anhydrite III accounts for a large proportion, while type III anhydrite is an unstable phase.

At the same time, the raw materials in the rapid calcination equipment only stay for a few minutes or seconds, which is very easy to cause uneven heat. In addition to semi hydrated gypsum, the proportion of dihydrate gypsum III and anhydrite in the production of building gypsum is high, and it is also converted into type II anhydrite. This type of building gypsum has a short setting time, which is suitable for the production of gypsum products, Improve the inventory turnover rate of product mold or the production volume of production line products.

Slow burning equipment should be used to produce plastering gypsum, gypsum binder, raw materials for gypsum joints and other powder gypsum building materials. The setting and hardening of gypsum produced by slow speed calcination equipment is relatively slow, which is beneficial to reduce the amount of water reducer and reduce the product cost.

Slow speed calcination refers to the calcination method in which the temperature of articles during calcination is more than 160 ℃ and the raw materials remain in the furnace for tens of minutes or more than 1h, such as continuous cooking pot, fluidized bed furnace, cement rotary kiln, etc. According to the temperature in the furnace and the time for raw materials to stay, the quality of calcined products is uniform and stable. The vast majority of its calcined commodities are semi hydrated anhydrite, a small amount of coarse crystal anhydrite III and undercooked dihydrate anhydrite.

In addition to the above factors, the calcination time, calcination temperature and the curing effect of FGD building gypsum production will endanger the production of FGD building gypsum.

The calcination equipment and processing technology should be selected in combination with the raw materials and desulfurization technology characteristics of wet flue gas denitration gypsum itself, and the main use of the waste after the solution, and the production process should be improved according to the analysis of the above influencing factors, so that its advantages and waste utilization can be used.