Grinding of clinker into cement has always been a rather important component of the cement manufacturing process. But it has assumed greater significance with the introduction of blended cements, particularly PPC,PSC. Advent and acceptance of Portland Pozzolona Cement by the regulators and the consumers have opened up the magical possibilities of simultaneously reducing carbon emissions, conserving natural resources, utilising hazardous waste materials, reducing cost, and on top of all, giving the customer a stronger "long-run" product. This has transformed the cement plant configuration forever, and brought in the concept of satellite grinding plants.
Traditionally, integrated cement plants were always located next door to limestone mines, for obvious reasons of practicality of transportation. Although, at times, driven by geopolitical and/or historical issues, crushed/uncrushed limestone has been carried over 20 to 30 kilometres to the cement plant by way of overland belt conveyors, ropeways, captive railways, etc., these have been more exceptions than the rule. As blended cement made inroads into the consumers? mind, the business model of split-grinding came into being as a logistical innovation. Transporting clinker (the cement intermediate) in the direction of the target market and sourcing fly ash from a power station en route, enabled setting up of standalone grinding and shipping facilities nearer to the marketplace. All this helped to reduce transport cost, increased the market footprint, and was a winning solution for all stakeholders like cement maker, cement consumer and the power generator. Even the environmental evangelists were for once, happy with the absorption of huge quantities of fly ash into cement. This has been one of the finest examples of combining manufacturing and logistics strategy for achieving greater competitiveness in the market.
One of the forerunners of implementation of this strategy was the Jafarabad clinkering plant of Narmada Cement, along with grinding capacities set up at Magdalla and Ratnagiri. Narmada Cement was the prime supplier of fly ash based Portland Pozzolana Cement (PPC) to Sardar Sarovar Dam on river Narmada. Coincidentally, these pioneering split grinding plants were implemented in the year 1982, which happens to be the watershed year for the Indian cement industry for another reason also – this was the milestone year when the industry was decontrolled by the government.
In no time, implementation of this innovative strategy of satellite grinding locations became commonplace all over India, and at the same time, grinding as a process came out from the shadows of clinkering, and started attracting a lot of attention and experimentation as a standalone component of the cement manufacturing process chain. Things like classifying, storage, conveying and blending of fly ash, also came under focus, in the cement industry parlance. Designers of cement plants started applying a whole set of new concepts to grinding technologies and logistics planning, and built these into the new layouts of the new-age stand-alone cement grinding units.
Adoption of blended cement in large quantities, helped our cement industry to substantially reduce both direct (energy savings) and indirect (transportation savings) carbon footprint of the product. In fact, due to our success in PPC, India is today the leading country in the world, with one of the lowest CO2 intensity per tonne of cement produced. This is something we can be justifiably proud of.