A process for the manufacture of bricks using waste materials like fly ash and bottom ash of coal/lignite fired fluidised bed combustion boilers

摘要

A process for the manufacture of bricks using waste materials like fly ash and bottom ash of coal/lignite fired fludised bed combustion (FBC) boilers which comprises: (a) mixing fly ash and bottom ash in a ratio ranges from 25:75 to 75: 25, adding binders such as lime cement with gypsum and sand ranges from 0-10% in admixture (b) adding an aqueous solution of chloride of Group 11 & Group 111 metals of iron, titanium or hydrogen singly or in combination for 10-25 minutes so as to obtain a mixture having solid, water ratio in the mix is in the range of 90-80:10-20, (c) allowing the said mix to soak and cool for a period in the range of 12-24 hours, (d) feeding the said wet mix into a press hopper which is maintained at a pressure in the range of 150-300 kg/square centimeter to produce the green bricks, (e) the green bricks are partially dried under shed for 24-48 hours to a moisture level of below 10% before putting it in steam chamber for steam curing.(f) the parti8ally dried green bricks obtained are put in steam curing chamber for curing at a steam temperature of 95 to 105 degree Celsius for 5-7 hours or 125-130 degree Celsius for 21/2 -3 hours (g) the green bricks are cured humid (100% RH) atmosphere at a temperature of around 40-60 degree Celsius for 5 days.