A large amount of fertile top soil from agricultural lands is used for the manufacture of Tiles and Bricks.  Since good quality clay is essential for both agricultural use as well as Tile and Brick industries, there is a severe shortage.  Thus the need for alternative, cost-effective construction products is immediate.  The situation is further compounded by the fact that new, cost effective technologies have to be developed locally as importing of technology is not economically viable in the Tile and Brick industry.

Iron Ore Waste Tailings – a hazardous by-product
India is the world’s sixth largest iron ore producer, generating about 18 million tones of Waste Tailings annually.  M/s. Kudremukh Iron Ore Co. Ltd. (KIOCL) is one of the major producers of Iron Ore in the country.  Situated in the ecologically sensitive region of Western Ghats, the company produces around 10 million tones of Waste Tailings per year.  At present, over 150 million tones of iron Ore Waste Tailings is accumulated at the Lakya Dam Reservoir, which has been constructed just to dump the tailings.  Storage and handling of these tailings is a serious environmental concern.  Safe disposal and utilisation of the tailings is a technological challenge.

The challenge

R&D Centre for Clay, Roofing Tiles, Bricks and other Ceramic products, National Institute of Technology Karnataka, Surathkal.

In order to save the Tile and Brick industry from the problems of raw material shortage and obsolete production technology, the Govt. of Karnataka has set up the R&D Centre at National Institute of Technology Karnataka.  The centre has carried out intensive research and developmental work in the field of conversion of various solid industrial wastes into value-added products.  With the available expertise in the field, the centre has made successful preliminary studies on the substitution of Iron Ore Waste Tailings for clay and other raw materials used in the manufacture of various building products.
Based on successful results obtained at the laboratory scale development, the project on establishment of Technology Development and Demonstration Cell for Iron Ore Waste Tailings based building products has been undertaken in Karnataka.  The project aims at development and demonstration of various technologies of making building products out of Iron Ore Waste Tailings of KIOCL.  The project will bring out an economically viable and environment-friendly technology with greater socio-economic benefits to the districts of Chikmagalur and its neighbouring districts including Dakshina Kannada and Uttara Kannada districts of Karnataka.  Replacement of up to 50% of clay will be done with tailings.

Physical properties

Chemical properties
(Typical)

Manufacturing process

The tailings available are blended with locally available clay and finely ground in a Ball Mill with water as the liquid medium.  The tailings used are in the range of 40% to 70% which replace the clay in conventional building products like roofing tiles, bricks etc.  The finely ground mix is filter pressed to remove excess water.  The resulting filter pressed cakes are then taken into two processes.  The water so removed is reused for the next batch of grinding.  Thus, water is conserved, avoiding water pollution.

This is followed by Extrusion and Semi-dry Pressing process.

Extrusion process
The filtered cakes are extruded for different shapes in a de-airing (vacuum) pug mill.  The extruded product is dried and kept for firing in the Shuttle Kiln 

Semi-dry Pressing process
The filter cakes are dried and granulated in a granulator for the desired granulate size.  These granules are mixed with a binder in a planetary mixer.  The output of the planetary mixer is taken to the Hydraulic Press to press social products like Wall Tiles, Floor Tiles, Telephone Bricks, Facing Tiles etc.

Advantage of Tailings-based products
Strength:  Meets relevant BIS standards.  Cost: 20% lesser than clay products.  Production Capacity:  4 tons/day (at Pilot Plant, R&D Centre, Surathkal).  Acceptance:  Local artisans are keen to know more about this technology.  The industry too has reacted  favourably for transfer of technology.  The centre plans to conduct training to artisans on a regular basis.

Environmental benefits
Successful implementation of the project results in a net savings in fertile land area to the extent of about 3,000 acres per annum in the state.  The present stock of Tailings will be sufficient for about 87 years at the present consumption rate for only roofing Tiles and Bricks. Reduced air and water pollution.

Thus the project has strong environmental and ecological benefits.

Spin-off technologies developed
Successfully designed and developed FCC and RCC roof tile supporting structures like Rafters and Reepers.  This has been used in the construction of the Pilot Plant.

Strengths of the project

For further details, please contact:

Shri N.N. Sampath Kumar
Co-ordinator

R&D Centre for Clay Roofing Tiles, Bricks and Other Ceramic Products
National Institute of Technology, Karnataka.
Surathkal, P.O. Srinivasanagar 575 025
Dakshina Kannada District, Karnataka State, India.
Tel: 0824 2476471  Fax: 0824 2476090
E-mail:  rdc@nitk.ac.in  Website: www.nitka.ac.in

Department of Forest Environment & Ecology (E&E)
Government of Karnataka
VII Floor, Multi storeyed Building, Dr. Ambedkar Veedhi, Bangalore 560 001.

Indo-Norwegian Environment Programme
#49, 2^nd Floor, Parisara Bhavan, Church Street, Bangalore 560 001
Contact: Mr. Chakravarthi Mohan, K.A.S. - Programme Co-ordinator INEP and Ex-officio Director, NGC
Mobile: +91 94482 82199         Tel: +91 80 2532 6185          Telefax: +91 80 2532 6186  
E-mail: ineptwo@vsnl.net        Website: www.inep-karnataka.org