Acid Mine Drainage Repurposed for Paint


After years of research, two professors from Ohio University recently announced the development of a full-scale treatment facility designed to remediate acid mine drainage (AMD) in southeastern Ohio.

Once operational, the treatment facility plans to extract approximately two million pounds of iron oxide per year from AMD to turn it into pigments for paint.

About AMD

For hundreds of years, coal was mined throughout much of Central Appalachia and the surrounding area. The Ohio Department of Natural Resources reports that between 1800 and 2010 the state produced approximately 2.35 billion tons of coal from its underground mines.

While coal is still being mined at several locations throughout the state and surrounding areas today, many regulations have since been adopted to better protect the environment and prevent pollution. Most notably, the Surface Mining Control and Reclamation Act, which was introduced in 1977, was implemented to prevent the abandonment of underground mines.

According to research, abandoned underground coal mines often result in the contamination of streams from a toxic sludge known as AMD. As water encounters the exposed mining rock, acidic wastewater results from the reaction, thus leading to the contamination of rivers and streams. Often observed as an orange or rust-like color, in worst cases, the AMD can devoid the waterways of aquatic life altogether.

In Ohio, it is reported that 1,300 miles of streams have been polluted by AMD. While these waterways can be cleaned up by neutralizing the acidity of the AMD, it is noted to be an expensive process.

Years of Research

To mitigate the issue more cost-effectively, Guy Riefler, an environmental engineer and Ohio University professor, began searching for a solution to the problem 15 years ago.

“It's a nuisance and an eyesore and an embarrassment really to the population. And because it's a poor area, it really doesn't get the attention it deserves,” Riefler told reporters.

As a result of his research, Riefler started extracting iron oxide from the polluted water and turning it into color pigments. His idea was to sell the pigments to further fund the AMD cleanup in the area, however, Riefler didn’t know much about paint to determine what made good quality pigments.

Coincidentally, around the same time Riefler began looking into this, Ohio University art professor John Sabraw was also starting to experiment with AMD. Reportedly trying to create paint from a jar of polluted stream water, Sabraw was not very successful.

It was then that the pair began working together on the issue and how extracted iron oxide could be turned into artist-quality paint. From what began as two separate science experiments, the duo developed a small-scale process to neutralize the acidity of contaminated streams and extract iron oxide particles.

“The modern artist is very good at engineering solutions to problems,” Riefler said. “I can't tell you how many times I got to a roadblock and I bounce it off John ... he'd come up with something that I didn't think of and just took us to the next level.”

In 2018, Riefler, Sabraw and local non-profit Rural Action partnered with paint company Gamblin to create a limited run of 500 oil paints. Dubbed the “Reclaimed Earth Colors” set, the paints funded their research-scale pilot facility.

What Now

Today, the team runs a social enterprise of Rural Action called True Pigments, which continues the mitigation of AMD in waterways by turning pollution into vibrant pigments for paint and other products. The enterprise was officially launched in 2019.

“Our goal is to bring life back to these tainted streams while making the U.S. iron pigment supply chain more sustainable,” reads True Pigments’ website. “Our technology and process can curb carbon emissions by creating a source of domestic iron oxide pigment production, decreasing the amount of iron needing to be mined or created through synthetic processes around the world.”

Due to be operational by 2024, the enterprise intends to launch operations of a full-scale treatment facility at the Truetown discharge at the Sunday Creek Watershed, a site in southeastern Ohio.

“Every single minute, 1,000 gallons of water is coming out of this abandoned mine. It's got a lot of iron and it's acidic,” said Michelle Shively MacIver, True Pigments' Director of Project Development. “Very little life can live in an area that looks like this.”

More information on True Pigments can be found here.


Tagged categories: Asia Pacific; Coating chemistry; Coating Materials - Commercial; Colleges and Universities; Color + Design; EMEA (Europe, Middle East and Africa); Good Technical Practice; Iron oxide pigments; Latin America; North America; Paint; Pigments; Research and development; Z-Continents

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