Development of Coal Fired Power Plant Aging Fly Ash and Bottom Ash Utilization

Abstract

Suralaya Coal Fired Power Plant (CFPP), with 3400 MW total capacity, contribute for 7.8% of the Java Bali transmission system load. Hazardous waste in form of fly ash bottom ash from Suralaya CFPP around 486,000 tons/year, consisting of fly ash 375,000 tons and bottom ash 111,000 tons. This research aims to maximize the composition of aging fly ash bottom ash (FABA) as raw material in lightweight aggregate (LWA) and nonstructural concrete products i.e. paving blocks, coarse aggregates and concrete panel fence. Testing was carried out until 90% mass composition of aging fly ash bottom ash per product. To ensure the product quality as result of FABA utilization, several tests were carried out such as compressive strength, material abrasion, material gradation, specific gravity and material absorption, and splitting tensile strength. From the abrasion test results, the lightweight aggregate has value 72.86% (the average natural aggregate has value <50%), fineness modulus 6.38 (average 6.3-6.9), and compressive strength 37.8-39.8 MPa at curing age of 28 days. The product meets the criteria of products standard of lightweight aggregate and concrete. By assuming the price of product 80% lower from market price, the economic value obtained can cover the investment costs and annual operational costs.