以磷石膏基α型高强石膏为原料,通过粉磨、缓凝、增稠等手段对其进行改性制备陶瓷模具石膏粉,以验证磷石膏在陶瓷模具领域应用的技术可行性.实验结果表明,磷石膏基α型高强石膏经粉磨7 min以及添加0.05%石膏缓凝剂1改性后,各项指标能够达到陶瓷模具石膏粉一类品要求;在此基础上添加0.06%黏度为6 000 mPa·s的羟丙基甲基纤维素醚对其进行增稠改性,可将产品吸水率优化至24%以上,达到陶瓷模具石膏粉二类品指标要求.
The feasibility of using phosphogypsum-based α-type high-strength gypsum powder as a raw material to prepare ceramic mold gypsum through grinding,retarding,thickening and other modifications is explored.The experimental results indicate that after grinding for 7 min and modification by 0.05%retarder 1,the product satisfies the requirements of class Ⅰ product indicators of ceramic mold gypsum.Further optimization can be achieved by adding 0.06%hydroxypropyl methyl cellulose ether with viscosity of 6 000 mPa·s,the water absorption rate is increased to over 24%,meeting the requirements of class Ⅱ product indicators of ceramic mold gypsum.