The demand for copper is skyrocketing, as is the pollution resulting from its environmentally detrimental production methods. The creators of a startup, Still Bright, believe they have discovered a superior, more eco-friendly approach to produce the copper that is essential worldwide.
This company employs water-based reactions, utilizing battery chemistry technology, to refine copper through a method that may potentially generate less pollution compared to conventional smelting techniques. The goal is that this innovative alternative will alleviate the escalating pressure on the copper supply chain.
“Our primary focus is on tackling the impending copper supply crisis,” states Randy Allen, cofounder and CEO of Still Bright.
Copper plays a vital role in a myriad of applications, from electrical wiring to cookware in contemporary settings. Additionally, clean energy innovations such as solar panels and electric vehicles are driving even greater demand for this metal. It is projected that global copper demand will rise by 40% by 2040.
As the demand increases, so too do the environmental and climate consequences of copper extraction, which involves converting ore into a pure metal. There are escalating worries regarding the geographic concentration of the copper supply chain. Copper is sourced globally, and traditionally, many of these mines would have on-site smelters to process their yields. (Smelters create pure copper metal primarily by heating concentrated copper ore at high temperatures.) However, the smelting sector has become more centralized, with many mines now transporting copper concentrates to smelters located in Asia, particularly in China.
This shift is partially because smelting processes are energy-intensive and chemical-reliant, often resulting in sulfur emissions that can degrade air quality. “They’ve shifted the environmental and social challenges to other regions,” mentions Simon Jowitt, a professor at the University of Nevada, Reno, and director of the Nevada Bureau of Mines and Geology.
While it is feasible to clean pollutants from smelter emissions, and modern smelting facilities are significantly cleaner than in the past, Jowitt notes that smelting hubs aren’t particularly renowned for their environmental stewardship.
Consequently, even nations like the US, which have substantial copper deposits and operating mines, predominantly transport copper concentrates—containing around 30% copper—to China or other nations for processing. (Currently, only two operational ore smelters exist in the US.)
Still Bright bypasses the pyrometallurgical methods employed by smelters in favor of a chemical method, partially inspired by devices known as vanadium flow batteries.
In the reactor utilized by the startup, vanadium interacts with the copper compounds found in copper concentrates. The copper metal remains solid, while various impurities are left behind in the liquid phase. This entire process lasts between 30 and 90 minutes. The resultant solid, composed of approximately 70% copper after this reaction, can then undergo another established process in the mining sector, called solvent extraction and electrowinning, to produce copper that exceeds 99% purity.
This is not the first endeavor to apply a water-based, chemical methodology for copper processing. Currently, some copper ore is treated with acid, for instance, and Ceibo, a Chilean startup, is attempting to implement a variant of that method for the type of copper that is typically smelted. The distinguishing factor here is the specific chemistry used, notably the choice to incorporate vanadium.
One of the founders of Still Bright, Jon Vardner, was investigating copper reactions and vanadium flow batteries when he conceived the concept of combining a copper extraction reaction with an electrical charging phase that could recycle the vanadium.
After the vanadium acts with the copper, the resulting liquid mixture can be processed in an electrolyzer, which applies electricity to revert the vanadium into a reusable form that can interact with copper once more. This process is fundamentally similar to how vanadium flow batteries store energy.
While alternative chemical methods for copper refining mandate high temperatures or extremely acidic environments to dissolve the copper and expedite the reaction to ensure complete interaction, Still Bright’s technique can be conducted at ambient temperatures.
A significant advantage of this methodology is its capacity to reduce pollution associated with copper refining. Traditional smelting heats the target material beyond 1,200 °C (2,000 °F), producing sulfur-rich gases that are emitted into the atmosphere.
Instead, Still Bright’s method generates hydrogen sulfide gas as a by-product. Although this is still a hazardous material, it can be efficiently collected and converted into beneficial products, according to Allen.
Another potential source of pollution arises from the sulfide minerals remaining post-refining, which can create sulfuric acid when exposed to air and water (this phenomenon is referred to as acid mine drainage, often seen in mining waste). Still Bright’s approach will also yield this material, and the company intends to monitor it closely to prevent any leakage into groundwater.
The company is presently conducting laboratory tests in New Jersey and designing a pilot facility in Colorado, which will be capable of producing approximately two tons of copper annually. The subsequent phase will involve a demonstration-scale reactor, intended to support an annual capacity of 500 tons and projected to become operational by 2027 or 2028 at a mine site, according to Allen. Still Bright recently secured an $18.7 million seed funding to aid in scaling up its operations.
The success of the scale-up will be a vital evaluation of the technology and whether the generally cautious mining industry will embrace it, notes Jowitt from UNR: “You want to observe what transpires on an industrial scale. Until then, there may be some hesitance to engage in this.”
