ZHU Fu-jie, ZHANG Xian, ZHOU Shuo, WEI Cun-di, MIAO Shi-ding*

(Solid Waste Recycling Engineering Research Center of Jilin Province, Open Research Laboratory for Physicochemical Testing Methods of Functional Minerals, Ministry of Land and Resources, Jilin University, Changchun 130022, China)

Abstract: A type of ultra-light ceramsite has been successfully prepared with raw material of white mud which is an industrial solid waste, fluxing agent of black cotton regur soil which is a swelling clay, and foaming agent of oil shale semi-coke. The ultra-light ceramsite, which meets the national standard GB/T 17431-2010, were produced under the optimized experimental conditions of the raw materials mass ratio (white mud: black cotton regur soil: oil shale semi-coke) of 7:7:6 and the optimal sintering procedure of being pre-sintered at 450 oC for 15 min and further being sintered at 1230 oC for 15 min. We have explored the suitable relationship between the sintering process of expanded ceramsite and raw material compositions, discussed the regulation of phase transition in the sintering process, and modified the range of compositions for preparing the foam ceramsite in the Riley's phase diagram. The prepared ceramsites have a bulk density of 355 kg/m3, a density rating of 400, a water absorption rate of 10.22%, and a porosity of 49.06%. The formation process of the ceramsite has been investigated using thermogravimetric (TG) analyses, polarizing microscopy (OLYMPUS), and scanning electron microscopy (SEM) .

Keywords: The ultra-light ceramsite; white mud; black cotton regur soils; oil shale semi-coke; phase transition; the Riley phase diagram analysis

ACTA MINERALOGICA SINICA Vol. 39, No.5, 2019, page 577-584