Cement firms change product mix, opt for pozzolana variety

Major players of grey cement in Gujarat such as Ambuja Cement, Ultratech and the Mehta group (Hathi and Siddhi brands) are switching over to portland pozzolana cement (PPC) from ordinary portland cement (OPC).

While OPC contains mixture of portland clinker and gypsum ground to a very fine powder, PPC is manufactured by blending a mixture of ordinary portland cement and pozzolana materials such as flyash, in proportions not less than 15 per cent and not over 35 per cent by weight of cement, according to industry experts.

O P Puranmalka, group executive president and chief marketing officer of cement, Ultratech, said, "At present, we produce 30-34 per cent of PPC in Gujarat. With proper infrastructure, which will be ready in the next two months, we aim to produce 75-80 per cent." Tata Chemicals is said to be the pioneer in producing PPC in Gujarat.

Ultratech was the first company to produce PPC at a higher percentage, he claimed. "Blended cement (PPC) is suitable for general construction, while OPC is more suitable for structure like high-rise buildings," he said.

On where Ultratech obtains the required flyash from, Puranmalka said, "There are two-three thermal power plants in Gujarat which regularly provide us with flyash. The company currently produces 80,000-85,000 tonne of PPC a month."

According to market experts, 8-9 lakh tonne of cement is sold in the state, of which Ambuja Cement has a major share of about 25 per cent . They said Ambuja is likely to produce 90-95 per cent PPC.

Prasanna Upadhyay, HR division, Ambuja Cement, said, "Our PPC-OPC ratio for Gujarat market is 60:40. We opt for PPC, as flyash adds to the strength of cement." The company sells 20 lakh tonne of cement in the western region, according to an official website.

Shridhar Shrimali, vice-president, sales and marketing, Sanghi Cement, said, "We are completely into OPC and have no plans to opt for PPC, as of now." Sanghi is believed to have the largest cement producing capacity in Asia.

Sand mixing in OPC and PPC is at different levels depending upon the nature of mortar or concrete works.

In some of the specialised concreting works, the addition of sand is restricted in PPC vis-a-vis OPC, technical sources said. Further, the coal imported after Tsunami was of inferior quality. Hence, flyash produced contained sulphur, which weakened the quality of cement, according to the sources.

The state has witnessed 8 per cent growth in the overall cement market in the last one year, according to industry sources.