摘要
从资源利用和物料平衡的观点看 ,稻壳最适宜的出路是制备用作混凝土掺合料的纳米SiO2 。实验表明 ,将稻壳控制在6 0 0℃焚烧 ,所得的低温稻壳灰 (LowTemperature-RiceHuskAsh ,L -RHA)由纳米尺度的SiO2 粒子 (约 5 0nm)疏松地粘聚而成。稻壳灰结构中除了以往报道过的微米尺度的蜂窝孔外 ,还含有大量由SiO2 粒子非紧密粘聚而形成的纳米尺度孔隙 (<5 0nm)。纳米尺度的SiO2 粒子和纳米尺度的孔隙是低温稻壳灰具有巨大的比表面积和超高火山灰活性的根本原因。活性试验显示 ,低温稻壳灰火山灰活性超过造粒硅灰 ,对普通混凝土和高强混凝土都具有强烈的增强作用。当低温稻壳灰替代水泥量为10 %～ 2 0 %时 ,可提高高强混凝土抗压强度 10MPa以上。
From the points of view of resources exploitation and material balance, the most suitable utilization of rice husk is to make nano SiO 2 to be used as the mineral admixture of concrete. Research results show that low-temperature rice husk ash burned at 600 ℃ (L-RHA) consists of nano SiO 2 particles (～50nm) sticking slackly with each other. Besides micron-cellular pores, there are many nano interstitial pores (< 50nm) formed by the packing of nano SiO 2 particles. The nano SiO 2 particles and nano pores are the basic reasons why the L-RHA is a “superpozzolan” with so great specific surface and so high activity. The activity test indicates that the pozzolanic activity of L-RHA surpasses that of palletized silica fume, and L-RHA has strong strength effect on ordinary concrete and high strength concrete. When the replacement proportion of cement by L-RHA equals 10～20%, the increase of compressive strength of HSC exceeds 10 MPa.
出处
《粮食与饲料工业》
CAS
2003年第6期40-42,共3页
Cereal & Feed Industry
