Paving the way: New technique for utilisation of zinc byproduct in road construction

Use of jarofix like waste material in road construction is an innovative technology and would show the way for utilisation of more industrial waste.

By Rahul Chhabra

Mounds of jarofix waste (zinc byproduct) near mines and industries in Rajasthan have gradually started shrinking as scientists have developed a technique that allows using the material as a substitute of precious soil needed for building highways. The development promises to reduce pollution, cut road construction cost and save lakhs of rupees that miners spend annually for the upkeep of these dusty mountains of waste.

The technique developed by Delhi-based CSIR-Central Road Research Institute has come as a permanent solution to dispose of nearly 60-80 lakh tonne of jarofix–the waste left behind after extracting zinc metal from ore–that is dumped around two mines/industries of Hindustan Zinc Limited at Chittorgarh and Udaipur.

Use of jarofix like waste material in road construction is an innovative technology and would show the way for utilisation of more industrial waste, said CSIR-CRRI director Satish Chandra. Anil Kumar Sinha, principal scientist, geotechnical engineering division, CSIR-CRRI, said, “We determined the properties of jarofix in the laboratory and recommended it for building road embankment and other layers of roads.”

Test road stretches using jarofix were laid on Rajasthan State Highway (SH-9) between Chittorgarh and Udaipur and a cost analysis showed that using jarofix as a substitute of soil, saves the builder about `4.5 lakh for every 1 km of road (single lane) of 1.5-metre embankment height, he said.

“The same technique is now being used for six-laning of a National Highway in Rajasthan, and almost 1.5 lakh tonne of jarofix from the Chittorgarh has been used so far,” said Dr Vasant G Havanagi, chief scientist. “Earlier, road builders needed to buy soil for laying embankment for highways, but jarofix comes very cheap and is readily available in areas close to the mine dumps,” Sinha said, adding even miners and industries end up saving resources and staff man-hours spent on ensuring that the waste dust does not pollute the air.

During the CSIR-CRRI study for exploring productive use of jarofix, three road stretches of 100-metre each were studied over three years to evaluate its performance. Jarofix was used alone and mixed with soil (in 50:50 ratio) on two separate test stretches. On the third stretch, no jarofix was used, but only the soil was used to compare the performance. The findings of the study showed that jarofix is a low-cost and stronger substitute for soil and can serve multiple purposes of waste disposal and cost-saving in road construction.