我厂几台20吨的低频熔锌感应电炉自1966年先后投产以来,炉子寿命平均只有3～4个月,通过修补使用最长也不过一年多。1974年以前一直采用高铝骨料正磷酸铝胶结的耐热混凝土作捣固料。由于这种炉料在高温(>1000℃)烧结下强度才大,而在熔锌温度420～520℃的范围内,是不可能达到烧结强度的;即使处在锌环周围的熔沟, I plant a few 20 tons of low-frequency induction heating furnace has been put into operation since 1966, the average furnace life of only 3 to 4 months, but also by using the longest but also more than a year. Before 1974, high-alumina aggregate aluminum orthophosphate cements heat-resistant concrete was used as tamping material. Since such a material has a high strength when sintered at a high temperature (> 1000 ° C), it is impossible to achieve a sintering strength within the range of a temperature of 420 to 520 ° C. Even in the case of a melt groove around the zinc ring,