Circular Economy – Using Mine Waste to Improve Mining Sustainability

Dr Raquel Balanay, Associate Professor, Caraga State University, Philippines and alumnus of Minerals Policy and Economics 2014, shares her research on circular economy. Her research is a collaboration with Dr Anthony Halog, University of Queensland and is funded through a Schlumberger Foundation Faculty for the Future Fellowship.

The mining value chain is characterised as a linear process that generates large volumes of waste. Circular economy is challenging this paradigm to improve sustainability of the industry by utilising and generating value from mining waste or making it available as a feedstock from which other industries can harness value.

Raquel’s current area of research is circular economy/industrial ecology (CE/IE) applications in mining and identifying applications of CE for the Philippines. It is a multidisciplinary field that involves engineering, chemistry, economics, biology, etc.

The implications of CE/IE application in mining is that it is a potential win-win solution by changing how we see mine wastes. The ultimate goal of CE/IE is designing wastes out, which means looking at wastes as sources of opportunities when these wastes cannot be avoided. It is because CE is a close-loop system that means no emissions and wastes from operations.

Mineralised waste is one of the largest industrial waste streams. Globally this is estimated to be between 4-15 Gt/year – a gigaton is equivalent to a billion metric tons or 1,600,000 - 6,000,000 Olympic swimming pools of mineralised waste. There are opportunities to make use of mineralised waste. They can remined or reprocessed. For example in Australia, there are synergies between industries where some industries take the wastes and by-products of mineral processing for separation, reuse, and conversion into useful products (e.g. fertilizers, cement, and plasterboard).

Further downstream, CE can be applied to waste recycling, notably electronic waste. For example to obtain the gold for network/telecom connectors – traditional mining would involve digging two miles underground, processing 1 tonne of earth to eventually get 2-5 grams of gold – alternatively recycling 1 tonne of old mobile phones could obtain 180 -300g of gold and various other precious metals including 8000g of copper. Apple is reported to have harvested almost $US40 million worth of gold from recycled gadgets in 2015.

Raquel has co-authored two papers with Dr Halog on “Charting Policy Directions for Mining’s Sustainability with Circular Economy” and “Promoting life cycle thinking for sustainability in the mining sector of the Philippines”. She has conducted some analysis of life cycle assessment of small scale gold mining in the Philippines and has put in a proposal to develop this work further.

In terms of challenges and a way forward Raquel observes that the coordination and integration of CE initiatives is where most of the challenge is. Mine wastes cannot be avoided in any mining activity. Stopping mine wastes means no mining, so instead of fighting over the issue whether to mine or not to mine if the area/country is indeed mineral-rich, it is good to anticipate how mining can produce wastes, what these wastes are, how these wastes can become input materials, what enterprises existing or to exist yet can take on the mine wastes as raw materials, and what policies can glue all these initiatives together so that pollution will be minimized at least cost by the industries and at terms beneficial to people in need of economic opportunities and to the environment that must be preserved.

She proposes that technologically rich countries should work with mineral rich emerging economies to close the loop and improve mining sustainability.

More details: https://m4dlink.org/spotlight/2017-07/circular-economy-%E2%80%93-using-mine-waste-to-improve-mining-sustainability