Could a new Jetti Resources breakthrough unlock low-grade copper ores?

Emily de La Bruyère, co-founder at Horizon Advisory.

Image: Horizon Advisory

Jetti’s catalytic technology enables the industry to meet a challenge by addressing a key technical problem – preventing the recovery of trillions of dollars of copper resources trapped in low-grade primary ores, often at existing operations. These low-grade resources contain more than 70% of the world’s copper reserves and they cannot be processed using traditional leaching processes.

Standard leaching techniques on primary copper ores are blocked by a hard, non-reactive coating, which forms around the crystal structure of the ore. This is known as a “passivation layer,” which prevents contact between the leaching solution and the surface of the mineral. Jetti’s catalyst enables the disruption of the sulphur metal bond of the mineral, allowing copper extraction by leaching to take place unimpeded.

The strengths of Jetti’s technology lies in its ease of use and its environmental credentials. The technology requires limited levels of capex as it can be easily integrated with existing plants and processes. The catalyst enables the use of hydrometallurgy, which requires less power, transportation, and water use than pyrometallurgy.

This means that 40% less carbon dioxide, 70% less sulphur oxides, and 70% less nitrogen oxides-associated emissions are generated when processing copper ore. Leaching also requires less than half the water that traditional pyrometallurgical approaches need to produce the same amount of copper.

Jetti makes it possible to produce copper in a more sustainable manner. The technology allows for the use of leaching systems on primary sulphides. These systems have a far superior environmental profile compared to traditional extraction methods. The environmental benefits include improved resource maximisation, significantly lower emissions, and lower water usage.

Jetti’s catalytic formulation is unique in that it integrates seamlessly with the existing heap leach solvent extraction and electrowinning (SX-EW) infrastructure already on site. Jetti’s soluble catalyst is added to the leaching solution, which percolates through the ore. After percolation, copper from the copper-rich leachate is recovered using the industry standard processes of solvent extraction and electrowinning to produce copper cathode.

Jetti’s technology has numerous benefits for our partners, including reducing operating costs, extending mine lives, converting waste streams and uneconomic deposits into valuable assets, and increasing copper production in a cost effective and environmentally responsible manner.

The technology has been proven commercially in partnership with Capstone Mining at their Pinto Valley Copper Mine in Arizona where, within one year, we were able to double production from a leach area containing hundreds of millions of tons of ore.

Jetti is now in advanced testing programmes with some of the largest copper mines in the world including 20 mines in Chile, Peru, and the US.

Prior to beginning operations, we undertake a number of tests on the ores we receive from each mine to quickly understand whether the ore type will likely be a good match for our technology. We then request a sample of their ore and do standard, industry-recognised laboratory testing to verify the approach. We also assess how best to deploy the technology in the field by looking at the existing infrastructure on site and selecting a location for a small catalyst addition facility.

Pinto Valley was a perfect candidate to pioneer our breakthrough technology given the abundance of primary sulphide copper resources available for leaching and the presence of an underutilised SX-EW plant and infrastructure in place. Jetti’s technology integrated seamlessly with Pinto Valley’s heap leaching and processing chain.

We began testing with Capstone in late 2017 and, after showing positive amenability results, construction of Jetti’s commercial facilities began at the mine site in mid-2019. We applied our catalytic technology to a leach area containing hundreds of millions of tons of ore.

At Pinto Valley, cathode production per area irrigated has doubled in one year. In their press release in July 2020, Capstone stated that it intends to significantly expand leaching activity, targeting approximately 280-300 million tonnes of historic leach stockpile and 175-185 million tonnes of high-grade waste over the remaining 19 years of mine life, creating 30 new jobs.

According to Capstone, they plan to generate strong cash flow from Pinto Valley’s underutilised 25 million pound per year SX-EW plant, which is currently operating at only 20% of capacity. Capstone’s plan is to increase cathode production to 300-350 million pounds from residual and high-grade waste over the next two decades. Working with Capstone, Jetti will continue to assess how best to deploy the technology in the field.

The potential of the technology is very significant; 70% of the world’s copper resources are trapped in primary sulphides that until now could not be extracted using traditional leaching processes.

Other approaches require massive capex, long timelines, and will be met with environmental and social challenges.

Our catalytic technology can be deployed in a wide range of situations, making it relevant across the copper industry. The catalyst can be used at mines with existing SX-EW plants on legacy dumps and at greenfield deposits, as well as at mines with concentrators that are unable to treat low-grade material.

There is a great number of mines that could benefit in terms of increased copper yield, longer mine life, and greater profitability from utilising Jetti’s catalyst. We are currently focused on capturing the significant upside from implementing our technology in partnership with these mine operators through as many deployments of the technology as possible.

The technology also has the potential to tackle the increasingly acute problems faced by miners by reducing water usage, improving energy efficiency, and minimising footprint. Water usage is especially important in the copper industry.

The biggest producers of copper globally are Chile and Peru, which are water-constrained countries. The copper industry faces an increasing need to improve its water consumption profile and hydrometallurgy, supported by Jetti’s catalytic technology, is key to achieving this.