Efforts to develop a water-based chemical method for processing copper are not new. Currently, some copper ores are treated using acid, and a Chilean startup named Ceibo is exploring a similar approach focused on traditionally smelted copper. The innovation in this case lies in the specific chemistry, particularly the use of vanadium.
Jon Vardner, one of the founders of Still Bright, was investigating copper reactions and vanadium flow batteries when he conceptualized a process combining copper extraction with an electrical charging step that allows for the recycling of vanadium. In this process, the vanadium interacts with copper, forming a liquid solution that is subsequently processed in an electrolyzer. This machine uses electricity to convert the vanadium back to a form that can react with copper again, akin to the charging mechanism of vanadium flow batteries.
Traditional copper refining methods often require high temperatures or highly acidic conditions. However, Still Bright’s approach operates at ambient temperatures. This method aims to reduce pollution associated with copper refining. Conventional smelting can generate sulfur-containing gases due to the high temperatures employed, while Still Bright’s process produces hydrogen sulfide gas as a byproduct. Although hydrogen sulfide is hazardous, it can be captured and converted into useful products.
Additionally, leftover sulfide minerals from the refining process can lead to acid mine drainage, a significant environmental concern. Still Bright intends to monitor and manage these byproducts to prevent contamination of groundwater.
Currently, the company is conducting lab tests in New Jersey and is planning a pilot facility in Colorado, which will be capable of producing two tons of copper annually. Following this, a demonstration-scale reactor is expected to be built with a capacity of 500 tons per year and is projected to be operational by 2027 or 2028. Recently, Still Bright secured $18.7 million in seed funding to facilitate this scale-up. The success of this initiative will be critical in determining its acceptance within the conservative mining industry.
Source: https://www.technologyreview.com/2025/11/03/1127474/copper-smelting-chemistry-clean/