Veena Sahajwalla, a native of Mumbai, is the director of the Centre for Sustainable Materials Research and Technology at the University of New South Wales in Australia
Last weekend, Sahajwalla was on one of her many visits to India, where she addressed a high profile seminar at the Scrap Recycling Conference: Emerging Markets. There, she told delegates about her pioneering effort in making “green steel” from, guess what? End-of-life rubber tires.
Polymer Injection Technology (PIT), a technology that Sahajwalla invented, can be used to recycle tires to replace coal and coke in the making of steel. While the two-day conference saw almost 300 delegates from the scrap and steel industry confab on issues ranging from the world business of recycling to automobile recycling in India, Veena’s presentation seemed to have created the most buzz.
The Indo-Australian scientist insists that her technology could be the answer to the growing global problem of disposal of waste tires globally. The United States, for example, was the largest producer of waste tires at about 290 million a year, but now China and India are giving the U.S. a run for its money because of increasing sales of new vehicles.
Automobile tires are made from a mix of natural and synthetic rubber, and various structural reinforcing elements including metal wires and chemical additives. The PIT introduces a modification into the conventional manufacturing process for steel. The technology precisely controls the injection of granulated waste tire material in conventional electric arc furnace (EAF) steelmaking, partially replacing non-renewable coke. Tire rubber, like coke, is a good source of hydrocarbons, which means they can be transformed in EAF steelmaking.
New South Wales University researched the replacement technology for years and, today, millions of waste tires are being transformed into high quality steel in Australia.
Recently, the same university also showcased a pilot micro-factory that safely transforms toxic e-waste into high-value metal alloys, offering a low-cost solution to what to do with the millions of phones, computers and other e-waste products plaguing India. Sahajwalla was involved in this project, too.
She told the Asian Scientist Magazine recently that a ton of mobile phones (about 6,000 handsets) contained about 130 kilograms of copper, 3.5 kg of silver, 340 grams of gold and 140 grams of palladium, worth tens of thousands of dollars. Sahajwalla explained that she used precisely controlled high-temperature reactions to produce copper and tin-based alloys from tossed out printed circuit boards (PCBs) while simultaneously destroying toxins.
All this is sweet music to the ears of Indian recycling industry. The country is the world’s second-largest mobile phone market, and the fifth-largest producer of e-waste, discarding roughly 1.9 million metric tons of such waste every year. Veena is confident that the PIT can solve India’s waste tyres problem.