Flyash a waste material from thermal power station of mahagenco posses dual problem of environmental pollution & disposal .The coals generally used are of inferior quality. Therefore the ash content in these coals may be upto 30% - 35%.
DISPOSAL OF FLYASH IS AN EXPENSIVE OPERATION DUE TO THE FOLLOWING REASON:-
(1) Ash deposition requires large area.
(2) It`s operational cost is very high.
*“If the flyash is not properly collected and disposed off it can create serious problems of air & water – pollution thus causing diseases like lung cancer , tuberculoris etc. Therefore from the point of view of public health , the process of ash disposal should be such that it should not affect the environment.”
*MAHAGENCO is Maharashtra largest energy conglomerate with present installed capacity of 10170 MW coal based station .Being the largest thermal power generating company in the Maharashtra state MAHAGENCO produces approx. 11.22 MILLION METRIC TONS of ash annually.Out of which 80%(approx. 8.98 MILLION MT) is fly ash and 20% bottom ash (MT).
*DISPOSAL OF FLYASH
Presently the fly ash & bottom ash is disposed by 3 modes:-
(a)Dumping in open land areas.
(b)Mixing with water & then discharging the slurry into prebuilt ash ponds.
(c)Discharging in ravines in close proximity.
*Generally a 1000MW thermal power station will requires nearly 500acres of land for dumping flyash in its useful life of 30 to 35 years.Normally flyash slurry to the extent of 10% to 20% concentration with water is formed .This slurry is than disposed off by pumping and is then let out in the earthen bund , where the flyash gets settele down & the clear water flows out through waste well. By continuous deposition of ash the water column get reduced and ash column reaches to finished reduced outgoing efficient starts getting turbid .
*This slurry is disposed of either in ravives in close proximity or in pre-built ash ponds. Disposing of in ravives again may lead to pollution cause this slurry gets mixed up with running water. This running water is used in irrigation , drinking process etc.
*So considering all the facts – disposal of slurry in pre-built ash ponds are supposed to be most asthetic and hygenic . The slurry is disposed by dumping and is then let out in the earthen bund where the flyash gets settled down & the clear water flows out through waste weir.