Because of the effective low thermal conductivity of gypsum powder, the Lai of Dashitai needs a long time of acidity to burn through uniformly, so in combustion, the Lai should be amplified by gypsum, and the core combustion distance is not too far. In order to avoid this situation, gypsum should be burned to the Long Elbow threshold at high temperature, but in this case, most products become "soluble" and "insoluble" broken gypsum.
Under production conditions, it is almost impossible to produce semi-hydrate with 6.2 water content. Measuring the amount of water produced by combustion is usually less than or greater than the above percentage. The product of the former is a mixture of hemihydrate (hemihydrate) and anhydrite; in the latter case, you get a mixture of hemihydrate and dihydrate.
Therefore, the reason for the uneven product is that when gypsum elbow burns, the gas is heated to high temperature steam, steam or other types of kiln wall installed in enzyme kiln with gypsum particles or gypsum, so that stone particles are located in the loss of complete dehydration in Han Dynasty. Gypsum naturally moves during the torsion of long P6, so the influence of high temperature on the positive particles of gypsum is very short.
This effect is not as obvious on larger gypsum particles as on the smallest ones (only a few microns in size), but only in a relatively short period of time when the gypsum particles are completely dehydrated and become anhydrite.
There are at least three kinds of changes in calcium sulfate in gypsum, namely dihydrate, nocturnal gypsum and hemihydrate. If the gypsum stays in the Wenlan container for a period of time, when the temperature of the container is approximately the same, the heat of combustion of gypsum will be transferred to a step-by-step color of gypsum, so that the whole dehydration becomes, density and hydration can become ordinary gypsum mortar.
In this way, a limited number of semi-hydrates can be produced, and soluble anhydrite can only be produced by combustion at temperatures higher than the required temperature for semi-hydrated salts. However, Wang Deche showed that the controlled tetracalcium gypsum was formed at the same temperature as the hemihydrate. In fact, it is advisable to make gypsum tables with less effective gypsum.