• Share

Metals and Minerals Are at the Heart of a Circular Economy

29 November 2022

Circularity is not new in the mining and metals industry, which has been integrating circular principles at the site level for many years, in part to reduce any negative impacts of extraction, but also because it makes good business sense. Reducing and recycling waste, increasing use of renewable energy, optimising water usage, regenerating closed mine sites and focussing on efficiency is already foundational to strategy in the industry.

But for materials to be truly circular, both the way they are produced and consumed must be circular. In the case of mining, this means having operations that have a net positive contribution to people and the planet, and working with the wider metals value chain to promote the responsible use and recovery of metals after they enter markets.

Our members are already making great progress in different areas of the circular economy.

Reusing Mining Waste With Vale

The largest waste stream produced by the mining industry is waste rock and tailings. As part of our members’ commitment to the safe and responsible management of tailings, companies are also focused on innovation to reduce the volume of tailings that need to be stored.

One way mining companies can help to reduce tailings while building a circular economy is through using tailings to produce something new.

Vale is developing a new sustainable source of silica made from the treatment of iron ore tailings, called Vale’s Sustainable Sand. Since 2013, Vale has been researching new opportunities to transform sand into new products and new business, and has created an open innovative ecosystem with more than 40 universities, research centres and other companies.

In 2021, Vale started producing and selling sand. Each tonne of sand produced represents one tonne less of tailings being disposed. About 250,000 tonnes of sand were processed and destined for sale or donation for use in concrete, mortar, prefabricated materials, artifacts, cement and road paving. This leads to a reduction in usage of natural sand, which is the second most consumed natural resource in the world, and also, a reduction in carbon emissions compared with the use of natural sand.

As part of its research in developing Sustainable Sand, Vale’s Pico Blocks factory was the first-ever pilot plant for civil construction products made from tailings waste in 2020. The factory processes up to 30,000 tonnes per year of tailings, resulting in a production capacity of up to 3.8 million pre-moulded products, including flooring and concrete blocks. The project is also helping to promote diversity and inclusion, as all the concrete block factory processes are operated by women.

At the end of March, Vale inaugurated the first road in Brazil using “ore-sand” in all four layers of the pavement. Each kilometer of pavement can consume up to 7,000 tons of tailings, and the 425m long road at the Cauê mine, in Itabira (MG), is expected to have a longer lifespan and reduced costs compared to the most commonly used materials for road construction, such as sand extracted from the environment.

Through this strategy of using waste to create new products, Vale reduces the amount of waste, usage of natural resource and carbon emission while also creating value.

Alcoa: Reducing water use

Water is a precious shared resource with high environmental, social, cultural and economic value. There is increasing pressure on the industry to identify and implement operational practices that reduce water use, increase efficiency and eliminate environmental impacts.

Alcoa was the first major refiner in Australia to adapt “press filtration” technology, which uses pressure to separate liquids and solids, to manage bauxite residue at its Pinjarra and Kwinana alumina refiner in Western Australia. Through this technology, the two refineries have the capability to reduce their freshwater use by a collective 2.2 gigaliters (581 million gallons) annually – the equivalent of the amount of water needed to fill 880 Olympic-sized swimming pools. This technology also reduces land use.

Alcoa is expanding the use of press filtration technology among its operations, with a new facility commissioned at its Poços de Caldas alumina refinery in Brazil. All of the refinery’s bauxite residue is now being processed through the filtration technology.

Building a Regional Circular Economy With Boliden

The transition to a circular economy will require innovative thinking on how to reduce and repurpose waste. In some cases, it is possible to turn one industry’s waste into a product or material which is useful for a different industry – this is called industrial symbiosis.

The Kokkola Industrial Park (KIP) in western Finland is one of the best examples of how this can be done to contribute to a circular economy within one region. Collaboration between companies and industries here is seeing waste from one process being provided as fuel for another and, by doing so, creating new value while reducing environmental impacts.

Boliden’s Kokkola zinc smelter provides excess heat and steam to generate heat and electricity for buildings in the area. This heat and steam would otherwise be lost, but now equates to the energy use of approximately 16,000 households in the region. Furthermore the energy is classified as carbon-free, as the main fuel in Kokkola’s roasting process is zinc concentrate, which contains almost no carbon.

Boliden is also turning sulphuric acid, a by-product of the mining process, into a raw material which is used other companies in the KIP. The sulphuric acid provided by Boliden’s sulphuric acid plant is delivered by pipelines in the industrial park to neighbouring industrial partners, reducing transport-related emissions and costs.

Recycling E-Waste With Atlantic Copper (Freeport-McMoran)

Companies can help to build a circular economy by recovering metals once a product reaches the end of its life. The global recycling rate of waste from electronics (e-waste) is still low, at around 20 per cent, so there is great potential for metals companies to flourish in this area. Atlantic Copper, part of Freeport McMoRan, is building a recycling system in Huelva, Spain, to recover copper, gold, silver, palladium, platinum, tin and nickel from e-waste. With an investment of 280 million euros, this project will see 60,000 tonnes of e-waste being processed each year.

Recovering these materials consumes less energy than obtaining them from virgin raw materials. This project also has the potential to generate 350 jobs, which will benefit the local community and economy.

Reducing Waste With Teck

The sector can contribute to the circular economy by reducing or preventing waste. In 1999, Teck launched an online platform called Mining Surplus to assist in the disposal of mining equipment from its 11 operating mine sites in the Americas and Australia. The platform has since been expanded and provides a market to sell used and surplus mining equipment from Teck and other companies.

Mining Surplus lists surface, mill plant, and underground mining equipment from copper, lead, zinc, gold, and coal mining operations. For example, in 2019, over 150 truckloads of shovel components from three mining shovels and parts were shipped into the US and reassembled into operating shovels. This both saved the used and surplus equipment from becoming waste, as well as reducing the demand for new materials for the companies who bought the equipment.

Recycling Batteries With JX Nippon Mining & Metals

In a business-as-usual scenario, most EVs, renewable energy infrastructure, and batteries are likely to become future waves of waste, negatively impacting people and the planet. Our industry needs to work collaboratively and engage across metals value chains to ensure that policy makers, product designers, and finance providers recognize the inherent suitability of metals for a circular economy, and that conditions are in place to prevent metals from becoming waste

Mining companies can help build a circular economy by bringing metals back into the supply chain once a product reaches the end of its life. JX Nippon Mining & Metals specialises in the recycling of minor metals contained in lithium-ion batteries, commonly found in vehicles, household appliances, computers, and other consumer electronics. It has developed a new process for recovering high-grade metal salts from electric car batteries, which involves pre-treating heating of the batteries to detoxify hazardous substances. This is followed by the leaching of nickel, cobalt and lithium in black mass by acid and then separating and recovering the metals using unique hydro-metallurgical technology.

These recovered materials, including high-grade cobalt sulphate, nickel sulphate and lithium carbonate, are fed back into the supply chain for use in new products. This use of recovered materials consumes significantly less energy than smelting or refining primary raw materials, and the quality of these metals is comparable to primary raw materials.