The potential value of fly ash, which is ejected during coal power generation and mostly goes to the dump, just got a bit more interesting. On Wednesday Orbite Aluminae, a junior that has patented a process to remove rare earths and alumina (aluminum oxide) from atypical sources, said it expected to be able extract alumina and rare earths from fly ash in a way that would be "economically viable."
Of course, the potential is huge and Orbite was sure to marshal out some salient power industry statistics about the coal hungry world we live in: chiefly that coal dominates world power production with a 41% slice of the energy pie. Indeed, that means a lot of fly ash. To give you some rough numbers, China, which is the single largest consumer of the world's coal, burns through about 4 billion (4B) short tons of coal a year, according to the U.S. Energy Information Association. The U.S. is next, at 1B short tons, followed by Europe, which uses nearly as much, and then India with 800 million (800M) tons.
For the top two coal users, China and the U.S., that dependence on fossilized energy equates with fly ash production somewhere around 500M tonnes a year. In 2010 the U.S. alone made about 130M tonnes of "coal combustion products," as some like to call these leftovers, about half of which was fly ash. "Our industry refers to these materials as 'coal combustion products' or 'CCPs' to emphasize that they have significant commercial value," the American Coal Ash Association writes on its website. But that said, most fly ash ends up in dumps, while about 40% is reused, primarily in the construction industry as concrete and filler. That so much goes to the dump suggests there is room for more commercialization, no doubt.
The implication is that if Orbite's technology proves viable at the industrial scale for power producers, then it could open up a large market for Orbite to sell its patented alumina/rare earth extraction processes. It's a similar situation for Orbite in the aluminum industry, for which it says it can render red mud waste, a nasty leftover in aluminum production, inert, and also extract alumina and rare earths. That has attracted the interest of major aluminum producers, which have signed memorandums of understanding with Orbite.
Of course, the clincher in the coal case is how well the technology translates to the industrial scale and by extension how economic the process ends up being for users. Will it be worthwhile to install and sell metal for coal power producers rather than throwing it out? Orbite stated this: "This new application of Orbite's technology is anticipated to be economically viable, based on different sources of fly ash, with an alumina content as low as 15%." It then noted minimum recoveries of 88% for alumina and in the 96%-range for rare earths, using its patented process, which involves acid leaching and then isolation of metals. For reference, Orbite pointed out that fly ash typically contains 5–35% alumina.
But what does Orbite mean by economically viable? I asked Orbite to explain and they said the following in an emailed statement. "In the context of our press release issued today, we used the terms 'economically viable' to explain that there is a positive return on investment coupled with a definite environmental impact reduction when using the Orbite technology based on different sources of fly ash with an alumina content as low as 15%. Using the Orbite technology allows the recovery of commercializable elements such as alumina, iron (hematite) and others stated in today's release to generate revenues for companies."
In other words, coal power producers could make money by selling metals in their fly ash.
It will be interesting to see how lucrative this return on investment may be at the industrial scale. If it is fat, coal power producers with suitable fly ash would be silly not to license the process from Orbite (as Orbite wants to do with aluminum producers as regards their red mud.) And by extension, if the return on investment is high, then Orbite could command premium licensing fees. Alternatively, if the payback is long and returns meager, then coal power producers would be less inclined to adopt the new technology, even if doing so would green-up their operations.
Kip Keen
Mineweb
