Setting standards in Sustainability
Plant Head, Kesoram Industries
Cement Division, Unit: Vasavadatta Cement
In an interaction with ICR, Chander Kumar Jain talks about the efforts taken by Vasavdatta to merit such applause. Excerpts from the interview.
How do you rate your company when it comes to sustainable production of cement?
We have installed Hot Disc instruments for utilising alternative fuel. We are utilising waste tyres, Plastic Waste, MSW as alternative fuel through Hot Disc, so use of additives is also reduced. All the waste is recycled in our plant. Ours is a green plant and we have got Green Co Gold rating from CII.
What is the scope for using raw material substitutes in cement production?
Cement manufacturing requires four elements as raw materials: calcium, silicon, aluminium and iron. The most common combination of ingredients is limestone (for calcium), coupled with much smaller quantities of laterite, bauxite (as sources of alumina, iron, and silica, respectively).
Cement is made with everything from seashells and shale to industrial by-products such as blast-furnace slag from steel plants and fly ash from coal-fired electric power plants. Cement plants are increasingly turning to industrial by-products that otherwise would be discarded. After completing detailed analyses to determine the effects on product chemistry and facility emissions, many cement plants are now using such by-products in the manufacture of clinker.
Please tell us about the measures taken by you for waste management?
Waste management at Vasavdatta is focused on three key aspects, viz;
1. Waste generated in the process of making cement (solid and liquid waste)
2. Utilisation of waste from other industry as raw material, and
3. Utilisation of waste from other industry as alternative fuel.
The treatment applied depends on the kind of waste to be processed. (see box for more details.
What are the benefits of co-processing wastes?
Co-processing of wastes has several benefits such as:
To what extent are you able to utilise low grade lime stone?
We are using online gamma ray analyser to monitor lime stone quality; as a result we are able to use low grade lime stone to the extent of 30 per cent in raw meal preparation.
Please elaborate on the water conservation measures taken by the company?
Water conservation measures at Vasavdatta include harvesting rainwater and its judicious use at and around our plants. The company believes in zero discharge philosophy. Some of the initiatives are detailed below.
Power Plant Pit
As this is a lime stone rich area, the rainwater does not percolate that well in the ground. So the rain water collected from the roof top and surface runoff is diverted by drains to the rain water harvesting pit at power plant. The total pit size is sufficient to collect 4, 00,000 m3 of water.
Rainwater harvesting at mine pit
Injepalli Limestone Mine has been developed systematically for rainwater harvesting. Since Gulbarga has scarcity of water, the cement plants of this region have to make their own arrangements for water. This called for the need for rainwater harvesting. The sump developed in the mine pit is utilised for storage of rainwater for its further use in the process during lean period. The quantity of rainwater collected, depends on the rainfall and the catchment area from where the water is diverted to the mine pit. For this purpose, Garland drains are cut around the quarry on the higher profile of the land channelling the rainwater from the catchment area. This water is then directed to the mine pit by opening the drain at desirable places. The mine sump has been developed to hold of 40,00,000 m3 of water.
Tell us about your green belt development programme?
Under its green belt development programme, Vasavdatta has planted 503,045 samplings as on March-2014. Survival rate was 54 per cent as on March-2013. The area covered in the afforestation programme is shown below.
Location-Area in Ha
Have you done any modifications in the plant lately to reduce emissions? Some the recent modifications and upgradations include:
What is the scope of using fly-ash in the cement manufactured at your plant?
We are injecting 32 per cent fly ash in PPC and are able to maintain same cement quality by proper blending and monitoring on continuous basis. We are using 100 per cent fly ash generated in CPP for PPC cement production.
How can IT be harnessed to reduce emissions and or to improve sustainability?
Better control and instrumentation systems over the years have ensured improved productivity of equipments resulting in optimised power and fuel consumption. Stack emissions are monitored in the central control room to ensure adherence to standards and corrective action. IT has become a lifeline in the modern age, without which information sharing and communication is difficult. It has helped to improve inventory management reducing inventory levels. Ambient air quality is also monitored online at Vasavdatta.
What are the challenges in switching to alternative fuels?
The main challenge in switching to AFR is inconsistent availability of the fuel. Handling is another major problem as the material often has obnoxious smell and it needs to be compacted as cubes before being fired in the calciner. Government policies too serve as an obstacle. We have to take permission every time we want to use a new material.
Waste management at Vasavdatta
1)Waste generated in the process of making cement
Over burden soil in mines
Entire over burden soil is transported into plant and colony to raise the ground level as well as give soil cover for plantation. In addition, the soil is used to make bund of sufficient height all across the mining lease boundary and trees are planted there.
Low grade limestone
Low grade limestone is kept separate and utilised by mixing it with high grade lime stone using suitable raw mix design.
Fly ash and bed ash
All the fly ash and bed ash is collected in five separate silos at power plant through pneumatic conveying. Both fly ash and bed ash are mixed in a silo and this ash is then transported pneumatically to cement plant in another silo where it is mixed and blended with other fly ash. After mixing the fly ash is used to manufacture cement by this we are able to use power plant bed ash, which is normally disposed in ponds.
Waste paper and packing wood
This waste is transported and processed for feeding into boiler.
These are sent back to original manufacturer for processing.
We have separate process tanks where effluent water is treated and pumped back to the cement plant. This is mixed further with fresh water and neutralised. The same water is utilised back in the cement manufacturing process. Hence, we are maintaining a zero discharge plant. Some part of water is also utilised for gardening and for spraying on the road.
Sewage water is treated through aeration system, clarifier, rapid sand filters and carbon filters. The waste sludge is stored in sludge drying beds. We maintain the prescribed standards for treated water and pump it to various gardens in and around colony and plant for gardening. Here too we follow zero discharge policy.
Lubricating oil and grease
All the lubricants, oil and grease from the plant are collected in barrels and stored on waste oil platform. We have oil storage tanks and suitable pumps to burn this oil and grease in our kilns.
2)Utilisation of waste from other industry as raw material
Our company has made various efforts to make quality PPC cement by utilisation of fly ash, which is a waste product of power plant. We have made arrangement for transportation, reception at Raichur Power Plant, NTPC, Ramagundam.
Chemical gypsum, which is a waste by-product of other industry making sulphuric acid, located at Tuticorin, Cochin and Vizag is also used at our plant. Gypsum is transported by rail wagon and stored in closed shed. This is used as a replacement of mineral gypsum by suitable adjustment into raw mix.
3)Utilisation of wastes of other industry as alternative fuel
Presently, we are utilising waste generated in other industries as alternative fuels. We have installed a new technology, Hot Disc, which is first in India supplied by FLSmidth. We are able to use 3.5/10 tonnes of waste per hour as alternative fuel. We have permission to co-process following waste in our cement kiln:
Co-processing in cement kiln ranks higher in the waste management hierarchy in comparison to other disposal options such as incineration and landfill. Unlike incineration and landfill, co-processing does not leave behind any residue that might have harmful impacts on the environment. Thus, co-processing is an ecologically sustainable solution for waste management.