Fly ash has become a precious commodity thanks to a Central government directive allowing more of it to be blended in cement. Cement companies are now vying with each other to get fly ash, hitherto derided as a polluting waste product spewed by thermal power stations using coal. With the Centre allowing up to 35 per cent fly ash to be blended with cement, it has become a revenue-earner for power stations too. APGenco has now been approached by companies including India Cements, Kesoram Cements, Zuari Cements, Panyam cements, Hyderabad Industries and Visakha Industries.