摘要 |
<p>Before the actual firing stage carried out in the region of 950 DEG C (G), this process comprises a preliminary stage of maintaining the product at a temperature of approximately 130 DEG C (E) for a period which can vary according to the degree of humidity of the product and situated between 1 and 10 minutes, the said preliminary stage being followed by a stage of increasing temperature from 130 DEG C to approximately 650 DEG C (F) over a period which can vary according to the nature and/or the particle size of the product and lies between 1 DEG C and 250 DEG C/minute, the said stage of rise in temperature being followed by a stage of maintaining the product at the calcination temperature of 650 DEG C (G) for 1 to 10 minutes. Furthermore, the actual baking stage is followed by a stage of progressive cooling comprising a plateau of being maintained under atmosphere at a temperature of approximately 850 DEG C (I) for three minutes, followed by a stage of linear cooling to a low temperature of approximately 100 DEG C. <IMAGE></p> |