Making Gorgeous Paint from Toxic Coal Mine Waste
Colors are serious business. Globally, pigments make up a $17 billion-a-year industry, tinting the world around you, from the white in your toothpaste to the blue in your bathroom tiles. Iron oxide, a chemical compound that creates earthy varieties of reds, oranges, yellows, and browns, is alone worth over $1 billion annually, with the market expected to grow substantially over the next decade.
But when it finds its way into rivers, lakes, and streams, iron oxide can also be a serious pollutant. At the sites of abandoned coal mines all over Appalachia, highly acidic, heavy metal-laden drainage poisons wildlife and colors waterways a deep burnt-orange. Guy Riefler, an engineering professor at Ohio University in Athens, Ohio, teamed up with artist John Sabraw on a project to clean up this polluted water, extracting the iron oxide and turning it into pigments that capitalize on the lucrative market. After years of experimenting in labs, their team is finally close to opening a pigment-producing test plant in Ohio, a state where more than 1,300 miles of streams have been tainted by mine drainage.
People have been tinkering with the idea of pulling pigment from mine sludge since at least the early aughts. But Riefler’s method is finally producing colors of a high enough quality to make consumer products: Portland, Oregon art supply company Gamblin has signed on to make a limited run of Reclaimed Earth Violet, incorporating iron oxide pigments filtered from the Ohio project. Make Change spoke with Sabraw soon after he closed out a successful Kickstarter campaign for the project, raising more than $33,000 in funding. Sabraw, who makes his own paints and creates artwork with the iron oxide, explains how the process works and how selling pigment could be a way to make cleaning up waterways pay for itself.
How did you first get involved in this project?
Professor Guy Riefler, an engineer here at Ohio University, was trying to solve this [iron oxide] problem, and thought the methods being used to deal with acid mine drainage were missing the mark, both in terms of cleaning up the streams and getting rid of the waste pollution. At the exact same time he starting to work on this, I started to train with a bunch of faculty on sustainability issues in Southeast Ohio...and I saw these streams on a field trip, just red, and orange, and caked with stuff. And they said it was iron oxide, and I was like, ‘I paint with iron oxide every day, I paint with this.’
And then, as often happens in small towns, I was watching my daughter's soccer game and one of the moms comes up to me, and she’s a graduate student working with Guy Riefler, and she was like 'hey, you're an artist, we need an artist, come meet my professor.’
What was it like when you first came in and started working with Riefler’s team? Did they just hand you some iron oxide in a vial, like ‘paint with this?’
It was actually in Mason jars. And it just looked like mud that you'd peel off the bottom of your shoe, it was horrible stuff. It was iron oxide but it didn't have any properties of beauty, or flow, or joy. It was semi-smelly mud, end of story.
And so the first couple years started off slow, They'd bring me samples, and I'd grind it, mix paint with it and test it out and tell them about the properties … and I'd say, let's see if we can get the crystals smaller, let's shift this orange. At the same time, I was trying to get people interested in what we were doing so we could get funding. That meant having exhibits, going out and talking about it. And it was 2013 when we started picking up steam, which coincided with the pigments getting much more sexy. So it was a good three years before we really had something that started to replicate a quality pigment.
You were learning about these environmental issues even before you got involved with the project. And you’ve probably also learned a lot since signing on. Can you describe this mine drainage problem in layman’s terms?
Sure. In Ohio, the bulk of the coal mining was done underground, deep underground. And until 1972, when the Clean Water Act was put in place, there were really no restrictions on what these people did. So most of them, when the coal was extracted and gone, they just left, and the mines, these networks of miles and miles of tunnels, were just left there.
Pumps were used to keep water out of the mines [when they were operational], but when they were abandoned, the water began to fill them back up. In the rock formations that we have here, there are sulfites present, and the water in the mines will extract those sulfites, and then the water itself becomes sulfuric acid, which in turn dissolves heavy metals into the water. Eventually, the water [in the mines] creates such a volume that in some places it blows out and starts finding its way into streams and waterways. And that's when you get an acid mine drainage seep. Now, we have hundreds of seeps that are leaching acid mine drainage into the streams in eastern and southern Ohio.
So are most of the problems due to the acidity of the water or the presence of the iron oxide?
It's a bit of both. Most of the acid mine drainage is coming out with a [very acidic] ph of 2, which is just crazy. The only things in these streams are these crazy diatoms and bacteria that can actually stand that kind of acidity. So the acid is a huge problem. But also, as the water meets sunlight, and oxygen, and temperature changes, the iron oxide and all the other heavy metals will precipitate out and go to the bottom of a stream. And that doesn't allow things to grow on the bottom of the stream and it kills say, fish eggs down there, and anything else trying to grow.
Does it impact human health?
If you drank out of that stream every day, that would be a problem. And in some of these locations there are small quantities of arsenic, lead, cadmium, chromium, that kind of thing. Really not good for you.
Can you describe the process of extracting the pigment and deacidifying the water?
The first thing we do is take the water and pump a bunch of oxygen in there. Because that will begin to make iron oxide in a crystal form that can precipitate out as pigment. To do that, we're building a big tower, and we'll have three different levels of trays with holes in them, think of it like three different colanders.
We'll pump the water straight from the mine seep up to the top of the tower and [the water] will fall into a large tank, where it'll settle, and the iron oxide crystals will fall to the bottom, leaving clear water up top. This water will go into a second tank and repeat the process, settling to let smaller crystals go to the bottom. And then it will go to a third tank and do it a third time. So here, all we're trying to do is to get the iron crystals to fall out, and get the heavy metals out.
At the end of that, the water should be very clean and virtually free of any heavy metals. But it's still acidic. So then it goes into another tank filled with steel slag, a hazardous byproduct of the steelmaking industry, which has a high ph … and can [neutralize the acid]. The water enters the slag bed and exits into the stream neutral. It will have virtually no heavy metals in it whatsoever, and it will be safe for aquatic life.
Where is this pilot plant situated? Is it near an old mine entrance? Where does it suck up the water from?
The plant we're building is in the middle of a town called Corning, like the glass. This was a coal mining town, where coal mining left. And somewhere in the late 1960s a mine seep began, that was coming out right next to the main creek that ran through town, Sunday Creek. ... That [seep] is still there, right in this public park in Corning called Algiers Park. So we got permission from the village of Corning to build our plant right there in the park, which is just grass basically, and a small pavilion where kids skateboard.
Your recent Kickstarter was for an “art wall” enclosure around the plant. Tell me about that.
I think I was just feeling bad about plunking a really ugly plant in the middle of Corning's public park. So in our proposal, I wrote that we would basically turn the plant into a piece of artwork… We're [also] going to be giving tours, and we want to make it educational for the public without being boring, or hideous, or corporate.
And the plant will capture all the water coming out of the seep?
No, for this pilot plant, we’ll be testing a percentage of the flow, about how much comes out of a shower tap. And we'll be testing that. … to really make sure we know how to scale it up. And that would be our hope, that we would prove this process by next year, and have our numbers solid, and we could [say] to the state, 'it works, it can pay for itself, it can pay for some jobs, it can clean up the stream. Pony up $3 million to build a full scale plant.' But say it in the nicest terms possible.
How much pigment will you be making in the pilot?
So the pilot right now, our best estimate is that we'll get a couple pounds a day. If we treated the whole flow, our estimates say we’d produce around 2,000 pounds per day. It's a lot. It's not just dirty water.
So when did Gamblin get involved, how did that happen?
They've been really amazing. [Company founder] Robert Gamblin started a different kind of paint company that was really focused on artists and artists’ needs, not just the bottom line. They've been developing a line of solvent-free, more sustainably oriented art products, so I thought they might be interested in this—and they were.
I was in Portland, Oregon, where their factory is located, and I just walked in. I just said 'hey, I have an idea.’ And they were like, 'no, please go away, no one can talk to you today, crazy man.' And I just kind of stayed there, and so their plant manager came out and he said, ‘alright, I have two minutes.' And then like three hours later I left.
They started testing our pigments in their labs, and sending out independent testers to make sure our toxicity levels meet their standards. And just a couple months ago they took 40 pounds of our pigment made 500 tubes of oil paint, and shipped them out to me. That's what we’re giving away with the Kickstarter.
And they're not selling it, it's just a promotion for the Kickstarter?
Correct. But obviously all of us hope that if we can get this full scale, that it will become a part of their paint line.
But the ideal thing for the pigment from the plant wouldn't necessarily be art supply stores. It would be industry, like concrete colorant, ceramic colorant, things like that. The market for iron oxide pigment in the US is huge. It's like 1.7 million tons or something, an epic amount of iron oxide. Before this [project], I had no idea. And I think on the market, right now, it sells for about a dollar a pound.
When will the test plant actually be completely up and running?
We got funding last summer to begin building the plant components, so we've been working since then. … Now we're just waiting for a little bit of a break in the weather. So we expect probably ... later in June, to actually start running water through.
And once it’s in full swing, what would ultimately make the pilot a success, to you?
If we can treat the mine seep before it gets to the stream, get rid of the pollutant in it, which is the iron oxide, by actually selling it, and then returning neutralized, clean water to the stream that's healthy for aquatic life, if we can do that—and we're really close to proving that we can—we're hopeful this can be replicated anywhere that this is a problem. That doesn't mean it's going to be easy. Every location has its own chemistry, its own problems. But if we can prove that it works here, it's possible we could eliminate most of this acid mine drainage within our lifetimes.