aditya kiran i vol.2 issue 1 49

Rawan Cement woRks

aditya kiran i vol.2 49aditya kiran i vol.2 49

By mR. Raj VeRma A perfect blend

Rawan Cement woRks

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The strength of the cement business’s strategic planning is evident in the decision

to set up a cement plant in india’s

Chhattisgarh belt. This belt is home to a liberal sprinkling of power plants and steel plants, which produce fly ash and slag as wastes.

Rawan Cement Works has the lowest-specific CO2 emissions among the UltraTech Cement plants. The plant has the added distinction of having

the highest usage of waste materials. How was all this achieved at a single plant? It’s all in the blend, we hear! Let’s hear it straight from one

of India’s greenest cement plants

Rawan Cement team: (Standing from left) Mr. V. P. Dubey, Mr. Amar Prem, Mr. U. N. Mishra, Mr. R. S. Sharma, Mr. R. K. Verma, Mr. C. D. Chitale, Mr. A. K. Shrivastava, Mr. T. Dewan and Mr. M. M. Ladha (Sitting from left) Mr. K. V. Rao, Mr. Ashish Ojha, Mr. D. K. Gupta, Mr. Rakesh Patnaik, Mr. P. K. Vishwakarma, Mr. K. K. Gajpal and Mr. Yogendra Verma

Rawan Cement woRks

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For the cement industry, these are not wastes, they are vital inputs - fly ash is used to produce Pozzolana Portland Cement (PPC), while slag is used to make Portland Slag Cement (PSC) – both popular blended cements. This process for producing PPC and PSC is eco friendly in more ways than one: it saves on limestone reserves and increases the life of the mines; it cuts short a lot of process, thus saving energy costs; and a lot of the high volume wastes are disposed of safely.

Keeping these benefits in mind, Rawan Cement Works was set up in 1995. Today, the product mix from plant includes 95 per cent blended cements.

Setting the standardThe Bureau of indian Standards has set the upper limits for the percentage of fly ash and slag that can be used in PPC and PSC at 35 per cent and 70 per cent respectively. This limit is difficult to achieve, the main reasons being the right quality of slag and fly ash is required as increasing the percentage of any of these could compromise the quality of the cement.

“At Rawan, a lot of expertise has gone into the manufacturing planning. in turn, the plant has achieved laudably high levels of blend,” said Mr. Raj Verma, Vice President, Technical, Rawan Cement Works. The plant has achieved the target of 31 per cent

mr. raj verma, vice president, technical, rawan cement works

At Rawan, a lot of expertise has gone into the manufacturing planning. in turn, the plant has achieved laudably high levels of blend.

Rawan Cement woRks

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for fly ash and 53 per cent for slag consistently throughout the year without compromising the quality norms.

With the guidance and experience of the business’s Technology and Research Centre, the unit adopted technologies and processes using chemical additives to aid in faster assimilation and greater saturation of fly ash and slag. The unit also increased the tricalcium silicate (an important mineral in portland cement) content and completely eliminated the use of iron ore – again saving a finite natural resource. It also altered the grinding technology to ensure maximum slag use.

Optimum quality Research showed that the cement easily achieves 3-day, 7-day and 28-day strength norms, but there was a reduction in the 1-day strength. Although maintaining

1-day strength is not a mandatory requirement, it is an unspoken need of the customer for speeding up construction work. The unit took special care to maintain 1-day strength even with higher percentage additions of fly ash by maintaining tight control of all the ingredients.

All this effort has paid off very well. Today, the average content of recycled materials in each bag of cement going out from the plant is around 38.3 per cent. And it also saves on natural resources, power consumption and ground and air pollution through industrial wastes. n

exploRing the gReen plant

(With inputs from Mr. Bimal Kumar Modi)