Mining mine waste for technology metals

Aptly named startup Phoenix Tailings seeks to transform a core concern within the mining sector, the waste materials from mining, into a profitable and sustainable new solution and market.

Founded in 2018, Boston-based Phoenix Tailings saw potential untapped value in the waste left behind by the refining of metals and decided to get into the business of mining this mine waste, which could revolutionize the sector if done sustainably and economically.

Intending to leverage this unknown and untapped benefit within the mining sector, the company's services engaged in taking mining and refining waste and treating it as a new ore that can be used by various industries.

Using specialized chemical processes, they pull apart individual primary metals that can later be used in everything from cell phones and laptops to automobiles.

These metals include titanium, aluminum, iron, silica and more importantly, rare earth metals.

The hope is to sustainably create primary metals as well as eliminate hazardous environmental waste, enabling industry leading manufacturing companies to have access to carbon-free environmental alternatives from metals mined out of industrial waste.

Mining tailings

The extraction of minerals from ore can be done in two ways, with placer mining, which uses water and gravity to concentrate valuable minerals, or hard rock mining, which pulverizes the rock containing the ore.

For hard rock mining, a chemical reaction is necessary to concentrate the minerals, which is done by comminution, grinding the ore into fine particles to facilitate extraction of target elements.

Due to comminution, the remnant dust, powder, and fine grains usually produced by a mill is mixed with water leaving residue in the form of a slurry. Once the sought-after minerals are extracted, these tailings are considered worthless to the mine operator.

These tailing are typically stored in some type of tailings facility, often a containment area known as a tailings pond.

Before modern regulations, mining operations often did not take adequate steps to making areas for tailings environmentally safe after closure.

Modern mines, particularly those in jurisdictions with well-developed mining regulations and those operated by responsible mining companies, often include the rehabilitation and proper handling of tailings areas in their costs and activities.

For example, the Province of Quebec, Canada, requires not only the submission of a closure plan before the start of any mining activity, but also the deposit of a financial guarantee equal to 100% of estimated rehabilitation costs.

Rejected minerals and rocks removed through mining and its processes have the potential to damage the environment due to released toxic metals, arsenic and mercury being the two major culprits; by acid drainage, usually by microbial action on sulfide ores; or by damaging aquatic wildlife that rely on clean water.

Currently, the greatest risk of tailings ponds is dam failure. With a worldwide average of one significant accident involving tailings dams each year, the cost of mine cleanup has typically been ten times that of the industry estimate.

At present, the most sustainable tailing and waste rock management is to stably contain this material; minimize the water and energy inputs, as well as the surface footprint of wastes; and move toward finding alternate uses.

And Phoenix may have found that alternate use – remining the waste to provide a new reliable and sustainable source of metals critical in technology.

Phoenix rises

The mining industry, each year, produces more than 172 billion tons of waste material that is thrown away each year.

According to Phoenix, this is enough tailings and other waste to cover the entire state of California in a foot-deep worth of sludge each year.

The tailing stored in ponds and other containment facilities, however, often contain a suite of metals that are not captured while recovering the target metal. These discarded metals are often considered critical to high-tech manufacturing.

It is estimated that the tailings disposed of by mining companies each year contain US$112 trillion worth of raw materials, with just one percent of that value being enough to make a fortune 500 company.

Among the most common examples of this potentially valuable waste comes from the process of aluminum refinement, the residue becomes something known as bauxite tailings or "red mud."

For every ton of alumina produced, nearly 2 tons of this red mud is left behind – a Tesla car is made of about 1 ton of aluminum, yet this produces roughly 3 to 4 tons of more red mud.

Phoenix Tailings' beachhead market has primarily been focused on red mud, in the process pulling out iron, titanium, aluminum, silica and rare earth elements.

But each individual type of tailings has many different types of metals in it, while currently focusing their efforts heavily on bauxite residue, they have dealt with platinum tailings, gold tailings, copper, nickel, and iron.

All across the board their system is successful as it was constructed from scratch which allows them to be dynamic and flexible to any individual feed stock.

This is accomplished with a closed-loop system that leaves behind nothing but sand, or a sand like residue, reducing over 70% of the tailings volume and extracting the value from it.

Using three separate processes of hydrometallurgy, solvometallurgy and electrometallurgy they are able to tailor their extraction systems to purify the waste, obtain the remnant value in the discarded material and clean up the toxic pools at the same time.

Being such a newly formed company, the influence Phoenix' work has yet to be implemented on a grand scale, and it remains to be seen if such a technology will be a sustainable solution for mine tailings. Rising from the tailings left behind by miners, however, Phoenix may just be creating an entirely new industry with enormous growth and potential within the mining sector, only time will tell.

Phoenix Tailings is one of the 15 current members of Prospect Mining Studio, a platform to support startup companies developing frontier technologies that will advance the mining industry. More information of Prospect Mining Studio can be read at Tech startup platform for mining industry in the April 29 edition of Metal Tech News.