Analysis and Testing of Muddy Soil from the Sediment Pond of The Mae Moh Mine for Portland Pozzolan Cement Production

DOI: 10.14416/j.ind.tech.2022.11.001

Abstract

The clayed soil from the sediment-trapping sump of the Mae Moh mine was examined to produce Portland pozzolan cement. The X-ray diffusion (XRD) analysis showed that the clayed soil consisted of kaolinite. After heat-treated at temperatures in the range of 700-900 ^oC for 3 h, the clayed soil samples were mixed with ordinary Portland cement at the ratio of 0, 10 and 20 wt.%, and then cured in lime water for 3, 7 and 28 days, respectively. XRD results of the cement samples from the process revealed pozzolanic phases as Tobermorite (Ca₅(Si₆O₁₆)(OH)₂.4H₂O) and Foshagite (Ca₄(Si₃O₉)(OH)₂) or CSH structure. Consequently, the 100 and 700-900 ^oC of heat-treated clayed soils were mixed with ordinary Portland cement and sand to form the mortar in the proportions of 0, 10 and 20 wt.% according to the mortar forming standard. The mortar sample was formed in a brass mold of size 5 x 5 x 5 cm., then cured in lime water for 3, 7 and 28 days respectively. The properties of the samples were tested according to the TIS 849 standard. The results showed that the samples with 10 wt.% of 700 - 900 ^oC heat-treated clayed soils achieved compressive strength according to standard. The samples with 10 wt.% of 800 ^oC heat-treated clayed soil after being cured for 28 days have maximum compressive strength. This study shows the potential of clayed soil from the sediment-trapping sump of the Mae Moh mine for use in Portland pozzolan cement production.