磷石膏分解特性对磷石膏制硫酸联产水泥新工艺的影响研究

Thermal Effects of Phosphogypsum on Co-Production of Acid and Cement

磷石膏预分解制硫酸联产水泥技术的关键是对磷石膏分解特性的深入了解,结合水泥新型干法预分解窑的特点,采用热分析及相关试验对磷石膏的热分解性能进行了研究.结果表明,磷石膏完全分解温度在1 300℃以上,在还原条件下其分解温度也在1200℃以上.结果还表明,由于磷石膏的分解温度往往高于该系统的最低共熔点温度,其对预热器分解炉的适应性较差,易对窑系统造成粘结堵塞问题.利用水泥新型干法技术分解磷石膏制酸并联产水泥的实施会有较大难度.

The key in acid and cement co-production by use of phosphogypsum with the new dry cement technology is to deeply learn the decomposition character of phosphogypsum.In this paper,studies have been made in the decomposition performance of phosphogypsum with the thermal analysis and the analysis of the cement new dry technology.The results show that the fulfilled decomposition temperature of phosphogypsum is about 1 300℃,and even in the restore condition,the temperature is above 1 200℃.It also shows that the flexibility of the precalciner and the preheater in cement technology for the phosphogypsum is not so good,and it can easily result in bonding and jamming in the cement kiln system,owing to the fact that the decomposition temperature of phosphogypsum is higher than its melting point.It,therefore,seems that the use of new dry cement technology in the decomposition of phosphogypsum and co-production of cement is difficult to implement.