PREAMBLE

 

Fly Ash utilization in India is currently a burning issue that needs to be addressed.

India generates 90 million metric tonnes of fly ash per annum but only about 10% (as per the Fly Ash Mission ‘98) of it is gainfully utilized. However a World Bank study of 9 National Thermal Power Corporation Ltd and other thermal power plants in 1997 has put this usage to 2%, the rest being dumped. (Annexure 1).

This compares unfavorably with most of the developed countries. In the USA, for example, the dry ash usage exceeds 34.2%, and Ponded Ash usage is 22.7% ( American Coal Ash Association ‘99) (Annexure 2). In Japan there is a 100% utilization of Ash (Center for Coal Utilization, Japan 1998). In most of Europe and in China too there is in-fact a shortage of cement/concrete grade fly ash.

The developing countries too have begun steps in this direction. The countries in the Middle East including the UAE have now made fly ash usage compulsory for all structures above 4 stories. Fly Ash retails there for US $ 80-85 PMT, which is higher than retail cement prices.

As these oil rich nations do not have coal fired power plants they are importing fly ash mostly from South Africa. An opportunity therefore exists for dry cement grade fly ash generated at Neyveli to be exported to the gulf countries due to its proximity to the sea.

What is the reason that the ash utilization in India is so pitifully low? Why have the other countries been successful in this field whereas we will be utilizing 1000 sq. km or one sq. metre of land per person for dumping ash by 2015 (World Bank), & recurrence of tragedies like the Nalco (Angul) Ash pond breach where 20 villages were swept away & 3000 hectares of fertile land has been silted

A paradigm shift is required in the Indian approach for finding gainful usage of Ash.

 

OUR PROPOSAL

ASHTECH will conduct a feasibility study to determine whether it is advisable to set up a cement plant in order to gainfully utilize the fly ash generated by the power plant at Neyveli. Whether a composite cement plant or a cement grinding unit can be set up will depend on the availability of limestone in the vicinity.

ASHTECH will also look into the other possible uses of fly ash and advise on the feasibility of the same. A write up on some of the key uses of Fly Ash is provided hereunder. ASHTECH enjoys the capability to advise on all these uses.

ASHTECH will specifically collect the latest research papers on all of the above topics and provide our comments on usage in the Indian conditions.

ASHTECH will undertake preparation of such documents that may be submitted to Central/State Government departments so that they can bring out important orders/ legislations on fly ash usage and concessions for the end users.

ASHTECH will also provide actual technical specifications of cement/fly ash/aggregate/water compositions after testing the concrete so obtained in Indian conditions at our laboratory at ABS Cement P Ltd. This would be necessary for educating the consumers.

ASHTECH will also advise on the wet and dry disposal process of fly ash, marketing (including exports), distribution, handling and packaging thereof.

ASHTECH would also consider being included on the list of entrepreneurs/companies invited to market fly ash.

 

 

 

POTENTIAL USES OF ASH GENERATED AT NEYVELI

 

Ash Usage in Cement Concrete:

That fly ash is beneficial as an additive in concrete - the second most heavily consumed substance by mankind (after water) is beyond doubt & established by all. In India 700-750 million metric tons of concrete is produced annually from the 100 MMT of cement every year. Our aim is to replace 25- 35% of cement at the construction sites, which is the expected norm all over the world. This would lead to an ash usage of 25to 35 million tons. For South India it translates to 8- 10 million tons of ash usage.

This is more than what Neyveli can produce.

Our plan is to educate the consumer & market this fly ash in 40 kg bags as replacement for cement in Portland Cement Concrete (PCC). The price of ash to the consumer to the would be around 40% of that of cement.

To achieve this an efficient & effective marketing & distribution network is required. The Indian consumer has to be educated on the benefits of adding ash to concrete including cash savings & ash made available at his doorstep

A leaf must be taken from the success of ISG resources in the USA (Annexure3). The company handles about 12 million tons of fly ash a year, and was started with the backing of Citicorp Venture Capital Ltd. It earned a tidy profit of $2.6 million on sales of $117.3 million last year. And it projects sales of $160 million this year.

In order to ensure that the fly ash generated is of the quality required for use in Portland Cement Concrete (PCC), the following sources of ash should be avoided:

· Ash from a peaking plant instead of a base loaded plant.

· Ash from plants burning different coals or blends of coal.

· Ash from plants burning other fuels (wood chips, tires, trash) blended with coal.

· Ash from plants using oil as a supplementary fuel.

· Ash from plants using precipitator additives, such as ammonia.

· Ash from start-up or shutdown phases of operation.

· Ash from plants not operating at a "steady state."

· Ash that is handled and stored using a wet system.

· Ash with LOI of less than 6%. (ASTM 618).

The net result of all these restrictions is that only a relatively low percentage (30-35%, at most) of all the coal fly ash produced annually worldwide is even potentially suitable for use in PCC. Neyveli Ash IS (if collected dry). Modern day power plants based on latest technology can produce upto 80% PCC grade fly ash.

Ash Usage in Cement

Fly Ash blended cement (PPC) too is gaining acceptance. The share of Ordinary Portland Cement is projected to decline to 57.9% (from 71% in 1998) by the year 2011, according to TERI. With a projected annual production of 180-200 MMT of cement by 2011, the share of fly ash blended cement IS: 1489 would be more than 25%.

This should account for a consumption of 6-8 million tons/annum of PCC grade fly ash in cement by the year 2011.

Other potential uses of Ash

Another important area of PCC grade ash utilization that can be taken up immediately is as a mineral filler (5-7%) for our bituminous roads. This is an accepted technology and the 33.5 million kms of our expressways will provide for another 0.5 to 1 million TPA of Ash usage. The Hot Mix plant owners would not be that difficult to educate.

We will also be advising on other various avenues of fly ash usage i.e.

· Fly ash brick manufacture. The only meaningful technology we think is that of FAL-G, but production is limited by the availability of Calcium Carbide sludge.

· Cellular Concrete products.

· Asbestos cement products.

· Usage with Ferro cement. Fishing fleets, coastal steamers, boats and barges etc.

· Refractory bricks - we believe that the central laboratory at Neyveli has developed a process for the manufacture of insulation bricks but the efficacy will have to be studied. Central Power Research Institute, Bangalore, too has developed another process.

· Embankments, backfills, land development etc (important for usage of bottom ash/pond ash

· Other uses.