Nimbahera in Rajasthan will soon likely gain the reputation of being the highest cement manufacturing area of Asia. The area is known for its Nimbahera stone, a kind of limestone used as a building material and raw material in cement manufacturing. Little wonder why it serves as an ideal destination for cement industries, and for Wonder Cement.
So a little more than four years ago, the RK Marble group, already a well-established name in marble mining and supply in Rajasthan, decided that it would develop on the vast available resources of limestone deposits available in the neighbourhood. It formed a sister concern, Wonder Cement. The management was keen on one thing and that is staying true to the RK Marble mantra of sparing no expense in selecting the location, machinery, and bringing out a world-class product.
The same year, the company appointed engineering consultant Holtec to conduct a feasibility study and in July Wonder Cement began placing orders for machinery to build the plant. It awarded the construction contract of the plant to L&T Construction. By April 2012, the company produced clinker and in June 2012 they produced its first batch of cement. The company was in business.
With a plant area of 200 hectares and a mining area of 740 hectares, Wonder Cement has an installed capacity of 3.25mtpa of cement. The mines have more than 330 million tonnes proved reserves and more than 25 million tonnes probable reserves. The total mineable reserves are more than 355 million tons. Open cast mining is done in both the mines.
At a time when most manufacturers try to skimp with installing latest technology-savvy machines at their plants or bring in global technology, Wonder Cement has had no such second thoughts.
SM Joshi, president (plant), Wonder Cement, says, “It’s a matter of pride for us that our chairman was keen that we should buy the best equipment available. For that matter, we are the first company to import cement grinding equipment that was recently developed by Thyssenkrupp.”
Consider this. Wonder Cement uses the latest hydraulic drilling machines at its limestone mines that offer a drilling rate of 40 metres per hour (mph) as compared to those generally available and offer 12-13mph. It has also brought in Komatsu PC 1250 excavators and Komatsu 64-tonne dumpers that help it mine raw material faster.
Limestone deposits are mainly extracted by bench mining in which holes are charged with ammonium nitrate and fuel oil explosive and blasted. The rock is excavated with front end loaders (10 m3 capacity) and loaded into 55-60 tonne and then transported to the crusher. Clay and shale normally extracted using front end loaders and loaded into haul trucks. When they occur as overburden, the clays and shale not used are stored and often reused for reclamation in the mined out areas of the quarry.
Approximately 93-95% of materials i.e. limestone & marl is used from captive mines for the preparation of raw mix for manufacturing desired quality of clinker. The other additives (5-7%) used after pre-blending by Staker and Recliner to control the moduli values in the mix include Red Ochre, laterite, bauxite etc. which are purchased from the outside agencies.
Although the plant works on continuous process, the manufacturer has utilised part of the land for buffer storage. It has a clinker storage capacity of 45,000 tonnes and 30,000 tonnes for cement of three grades. Besides this, its packing system has three lines for 12 truck loads and a similar number of wagon loads.
The process of manufacturing of cement can be divided in the following sections: Mining, crushing, raw material grinding, coal grinding, Pyro-processing, cement grinding and cement packing.
Vivek Patni, director at Wonder Cement, says, “The limestone crushers that we use come from L&T and they crush 1,500 tonnes per hour (tph). Our transport and conveyance equipment and elevators also come from Germany.”
While raw material acquisition and refining is one of the most important stages of cement production for which Pfeiffer has supplied the latest VRM technology, the equipment for Pyro-processing and clinker grinding is supplied by ThyssenKrupp. This recently developed technology offers Wonder Cement narrow particle size distribution, which offers the cement strength as well as durability. It is for this reason that the company stayed clear from using local available technology. Wonder Cement is also the first manufacturer to deploy this technology in India.
In terms of equipment, there are different mixes of technologies available for cement manufacturing. However, the management refrained from opting for a single supplier for all its equipment requirements. So it preferred to buy from different suppliers and thus integrate the same into the plant.
To control consistency, the company has installed PGNAA+PFTNAA (on line analyser Gamma Matrix) that controls the quality of incoming raw material, a fully-automatic Quality Control Lab Polab equipped with XRF & XRD (X Ray Florescence & X-ray Diffraction) ARL and particle size analyser (Malvern) for better control constancy in raw mix.
The plant is fully automated with latest German technology and quality control is done through Automated Po-Lab (Robotic Lab) with AQCNET software. AQCNET/POLAB configuration consists of a standard industrial robot placed in the centre of a circular arrangement of sample preparation and analytical equipment. Samples arrive automatically from the connected automatic sample transport system or are entered via operator sample conveyors or special input/output magazines. The POLAB computer integrates the system components. It identifies incoming samples, downloads the relevant sample-handling specification and controls all intelligent devices in the configuration. Sequence control includes priority handling and intelligent handling of equipment failure situations.
The company uses the latest packing technology like three 16 spout packers, 12 WLM and 9 TLM with combined capacity of 720 TPH at the plant. Other auxiliary equipment are supplied from the best in the industry such as L&T, Aumund, Thermax, Elecon and Kaeser.
Joshi says, “We execute quality control at every stage of the manufacturing using robotic technology. We use cross belt analyser, which is the world’s best Combi CBA having CNA technology and analyse the entire quality of limestone being crushed and not just a mere sample. This gives an accurate chemical analysis of the limestone. In process quality control, we have sample preparation units at different stages where automatic sample is drawn and packed in a bottle and despatched through a robotic lab through a pipeline with no human intervention.”
In terms of being sustainable, the company uses a pre-heater technology that is low on fuel consumption. It uses petroleum coke (petcoke) instead of fossil fuels. The advantage of its location in the north zone enables the company to use petcoke as it’s cheaper than other fuels.
Considering that Wonder Cement is mainly a manufacturer, R&D becomes redundant. It prefers to refer to NCBM (national council for building materials), a government research institute in Delhi. Innovation is another that the company does not need to indulge in. Cement in India can only be sold under BIS licence, which offers fixed norms for each grade of cement. “You have to make within that grade. If you produce something outside the give grade, then it will not be permissible for sale,” says Joshi.
So how does the company employ latest techniques to retain employees? Joshi says, “Employee training is important as need to retain them. Nimbahera has a decent training centre set up by our government in league with the Danish government.” The company also offers a great township and facilities for employees.