EFFECT OF COMBUSTION TIME ON COMPRESSIVE STRENGTH AND WATER ABSORPTION IN RED BRICKS MADE FROM TAILINGS AND CLAY RAW

Abstract

Indonesia is the sixth largest bauxite producer in the world with 98 bauxite mining business permits in Indonesia and 84 of them are in West Kalimantan. If we look at the high bauxite production every year, the potential for waste produced is no less large. From the washing process, a by-product (waste) is produced which is called bauxite tailings. The resulting bauxite tailings account for up to 50% or more of the bauxite weight before washing. Bauxite tailings have physical properties by the fine aggregate standards for building material specifications part A (SK SNI S-04-1989-F) with a grain size of (-2+0.075) mm. They can be used as a substitute for fine aggregate from the natural environment. In this research, bauxite tailings, which are waste from mining activities, are used to make a product that has added value, namely red brick. Red bricks are mostly made from clay, but in this study, bauxite tailings were used as raw material with clay as a mixture. This research aims to determine the compressive strength and air absorption values of red bricks made from bauxite tailings mixed with clay at varying firing times of 7, 14, and 21 hours. From the test results, it was found that the longer the burning time, the higher the compressive strength value but the lower the air absorption.