Wednesday, November 7, 2007 - 6:00 PM
494f

Experimental Investigation into Tailings as An Ingredient Material for Belite Mineral

Guoxian Xiao1, S. Ding2, Guoqiang Zhang3, Ci Zhou4, and Zhihai Gao3. (1) Dept. of Material Engineering, Soochow Univ, Suzhou, China, (2) Postec, Tel-Tek, Kjølnesring, Porsgrunn, Norway, (3) Dept. of Material Engineering, Soochow Univ, Suzhou, 215021, China, (4) Soochow Univ, Suzhou, 215021, China

The gold tailing regarded as the waste material in the nonferrous metal industry can be used as the sleazy raw material of the building materials industry. There are a large amount of SiO2, CaO and a small quantity of Al2O3 and Fe2O3 in gold tailing, but there are a large amount of CaO and a small quantity of SiO2 in limestone. So it is an effective measure to produce high belite cement by burning gold tailing with limestone. Now the development of the high-belite cement is hotspot in cement industry. The dicalcium silicate mineral (known as C2S, belite) in cement has, compared with the general silicate cement, better properties in for example low heat hydration, good in durability strength and small quantity of CO2 release, and caused many researching activities recently. In the present study, investigations were carried out in order to find an operation condition, under which the belite minerals C2S could be produced with the tailings. The possibility of producing new brand cements was also to be explored by blending the belite minerals with the certain amounts of silicate cements. The results show that the property of the high belite ingredient is excellent when a mixture of the tailing and the limestone in a ratio of 1:1 (in weight) is burned at 1350°C for 1 hour. Pozzolana cement of C42.5 can be made when 30% high belite blending (burned at 1350°C) is added in ordinary silicate cement; Pozzolana cement of grade 32.5R can be produced when 45% high belite ingredient (burnedg at 1350°C) or 30% high belite ingredient (burned at 1250°C) is added; Pozzolana cement of C32.5 can be produced when 45% high belite ingredient (burned at 1250°C) is added. Therefore, high-belite ingredient from gold tailing can not only reclaim a large amount of gold tailing and protect environment, but also reduce the cement production costs and bring out good economical, social and environment benefits.