PREPARATION OF GEOPOLYMER CEMENT FROM CRUSHED STONE BY-PRODUCT USING ALKALI FUSION

Abstract

In the crushed stone production process, crushed stone fines, such as dust and slurry cake, are
generated as by-products, and most of them are landfilled. Recently, it is becoming difficult to secure landfill
sites, and effective utilization of by-products is desired. On the other hand, geopolymer cement has attracted
attention due to the higher acid resistance than that of ordinary Portland cement. In this study, we attempted to
prepare geopolymer cement from crushed stone by-products using alkali fusion. In the experiment, crushed
stone dust, discharged from one of the quarries in Japan, the fused dust, which prepared from the dust by
heating at 500 o
f with NaOH addition (weight ratio of addition is 1:1.6) for 0.5 h using rotary kiln, tap water
and coal fly ash were used as raw materials. Crushed stone dust, fused dust, and tap water are mixed on various
mixed ratio, with or without the addition of coal fly ash, heat at 30 o
f or 80 C for 24 h, and then stand at room
temperature, in the air or distilled water to prepare geopolymer cement. Acid resistances for the obtained
product and ordinary Portland cement was also investigated. As a result, 7 g of mixture of crushed stone dust,
water and fused dust (mix ratio is 1: 1: 2) with 3 g of coal fly ash, heated at 80 o
C, and cured in water to obtain
the geopolymer cement with hard structure, and the obtained geopolymer cement indicates higher acid
resistance than ordinary Portland cement.