AN INVESTIGATION OF PELLETISATION OF FLY ASH

Abstract

Pelletisation of fly ash collected from Guru HarGobind Thermal Plant (Lehra Mohabbat), Punjab, has been investigated in this thesis. Pelletisation was carried out using a pelletiser fabricated by modifying a tilting-drum type of concrete mini mixer. The parameters investigated during the pelletisation process were: angle of pelletiser drum axis with vertical, rotational speed of the pelletiser and duration of rotation. The raw materials used in the pelletisation were water, fly ash, lime (as a binder) and coke (to sustain high temperature during sintering). The hardening of the pellets was carried out by sintering by exposing the pellets to a temperature of 1000°C for a period of 1 hour. Taguchi analysis of the test results indicate that the maximum value of the 10% fines for pelletised aggregates is obtained for the following conditions with respect to the test parameters: minimum value of angle of pelletiser drum in the selected range and maximum value of the rotational speed and the duration of rotation in the selected range. Results of Taguchi analysis of the test results with respect to water absorption of the pelletised aggregates, specific gravity, bulk density and percentage of voids have also been reported. The limited test results of the investigation indicate the potential for use of the pelletised aggregate in light weight concrete or non-structural applications