Recycling of cement kiln dust and waterglass sludge in the manufacture of acid resistant masonry units

Abstract EN

The objective of the reported paper is to study recycling of some Egyptian wastes with a clay raw material in the manufacture of acid resistant masonry units.

These include acid resisting bricks for using in the sewage canals and tanks lining as well as in structures requiring low absorption and high resistance to chemical action.

This is a dual target for economic benefit and environmental pollution protection.

Accordingly, four batches composed of Kafr Homeid clay (KHC) and wastes of cement kiln dust (CKD) and water glass sludge (WGS) were suggested for this investigation.

Articles from each batch composition were prepared by pressing then firing them at temperatures ranging from 1075oC to 1150oC at 5o / m (firing rate) and 4 hours (soaking time).

The CKD and WGS wastes were added in different percentages ranging from 25-40% and 10-25%, respectively.

To assess the product properties the testing methods outlined in the ESS 41 : 1986 and ASTM C32-93 (2000) standards were applied.

Consequently, the suitable mixtures design that fulfill these specifications were selected, taking into consideration the industrial economy and environmental protection factors.

It was found that the most applicable articles which achieve the applied specifications were prepared from batch T3 after firing at 1125oC having 50% clay, 30% CKD and 20% WGS.

Also, batch T3 successfully achieved comparable properties of water absorption, weight loss due to acid attack and compressive strength and deserve to be the most applicable and superior one from the industrial point of view.