Forum Message

Heading: ash Compositon
Can Bottom ash be use instead of Fly ash inconcrete as subsitute to cement? Does anybody have information about chemical composition of bottom ash? does it have heavy metals?

Mario Bacic

Pulverised fuel ash or fly ash is used as a partial replacement of cement because it is pozzolanic in character. It acquires the characteristics because of the glass content, formed during the coal combustion in the boiler. Bottom ash does not contain glass, hence cannot replace fly ash. However it can be used as fine aggregates in concrete, after removal of carbon and proper testing.

Dr J D Bapat
Dr J D Bapat

I agree with Mario Bacic, in addition to his comments I would also add that Bottom ash contains sulfur as well, depending on the source of coal and burning procedures.

Mahfooz Soomro

I wonder if any followers of this thread would be interested in our alternative to fly ash in cement production: It is called VALOXY,a secondary alumina material produced by RVA in France.

VALOXY, comprising nominally around 70% alumina, is derived from the process of recycling salt slags generated by the aluminium refining industry. Use of Valoxy as a source of alumina can significantly reduce the cost of raw material formulations cement production as well as process benefits. Valoxy is used by several globally-known cement producers

VALOXY offers the following benefits:

· Predictable supply

· Stable low-cost pricing arrangements

· Saves on virgin material extracted from nature

RVA is located at Les Islettes, 200 km east of Paris and produces 50,000 tonnes VALOXY per annum.

We would be very pleased for the opportunity to provide technical information and a sample for evaluation.

Details about RVA can be found at

Howard Epstein

Howard Epstein
   Click Here to Reply    Areas
Advertise Here