CAPE TOWN (miningweekly.com) – A leading academic has called for a joint committee to track products that use minerals and metals to better understand how much stock is circulating globally.
“Knowing how much stock is in use enables one to estimate demand over the next few decades, taking into account global growth and the replacement of existing stocks,” Yale University Professor Emeritus of Industrial Ecology Thomas Graedel told delegates at the thirty-fifth International Geological Congress (IGC), in Cape Town.
He said that quantifying geological stocks was a “grand challenge” and was key to better understanding long-term sustainability prospects.
“We need to start with what we know about the stocks in use and measure year by year the inflow and outflow of a given material.
“When it comes to inflow, we have to ask where the material, such as copper, is being used. Twenty-one kilograms of copper is used in the average automobile, with 200 kg of copper used in the average home in Europe and North America. We need to multiply that by how many cars and homes there are and repeat this analysis for all metals. That is a big challenge . . . and we can only sketch answers to some of it.”
Graedel said it was difficult to estimate how long products are used for, but this was important as well. For transportation, products are typically used for 15 years, and 75 to 80 years in the construction of houses.
He suggested forming a joint committee involving the International Council on Mining and Metals, the Materials Research Society and the International Society for Industrial Ecology to deal with the challenge.
“It’s in everyone’s interests to regularly convene a group of experts to track products using minerals and metals,” he noted.
He said this would lead to a better understanding of urban mine stocks and their losses and could provide better information on discards and the recycling of industrial products.
Rates of recycling were another significant challenge, with more understanding needed on this front.
He said selenium used in fertiliser was recyclable but aluminium, for example, was “unrecyclable as best we know. We can recover it, but we don’t know what to do with it.
“The cycle of metals is a systems challenge, but we don’t understand it. We have to do better with this challenge,” he said.