微波煅烧硅酸盐水泥的研究

Microwave Sintering of Portland Cement

用微波在 1 370℃ ,1 40 0℃ ,不同生料组成下煅烧了硅酸盐水泥 ,并与在 1 45 0℃的电炉煅烧进行了比较。结果显示 :微波煅烧比电炉煅烧的温度至少降低 5 0℃ ,煅烧时间减少约 70 %。微波煅烧(1 40 0℃ ,1 0min)水化活性优于电炉煅烧 (1 45 0℃ ,30min) ,强度也提高。同种生料 ,两种不同煅烧模式得到的熟料中 ,其四大矿物 (C3S ,C2 S ,C3A ,C4 AF)是相同的 ,阿利特相结构都属于Ⅲ型和Ⅰ型单斜晶系 ,但微波煅烧的熟料中硅酸盐矿物 (C3S+C2 S)总含量提高了约 1 0 % ,晶体的尺寸较小且比例较高 ,中间相 (C3A+C4 AF)的含量降低了约 1 0 % ,黑色中间相的尺寸有增大趋势。结果还表明 ,适宜的组成有利于微波烧成硅酸盐水泥 ,并且其矿物形成过程也不同于电炉煅烧。

Portland cements with different composition of raw materials were sinteres at 1370℃ and 1400℃ by microwave.The comparison between Portland cements sintered by microwave and by electrical furnace at 1450℃ was made.It is shown that the temperature and time by microwave sintering reduce 50℃ and 70% respectively,compared to those by electrical furnace sintering.The hydrated activity and strength of the cements by microwave sintering are higher than that of the electrical furnace sintered cements.The sintered cements obtained with the same materials but different sintering methods have the same mineral phase,such as C 3S,C 2S,C 3A,and C 4AF.The phase structure of Alite is Ⅲ and I type of monoclinic system.For sintered cements by microwave,the total contents of si licate mineral,with smaller crystal size and higher proportion,increased about 10%,the content of middle phase(C 3A+C 4AF)reduced about 10%,and the size of black medium phase tended to increase.The proper composition is benefit to Portland cements by microwave sintering.