Page 4 - Green Builder Nov-Dec 2021 Issue

EDITOR’S NOTE

The Inside Scoop

The Tangle of Transparency

Fly ash may finally come clean, as the ‘big guns’ follow their self interest.

N INTRIGUING STUDY CAME ACROSS MY DESK YESTERDAY, titled “Environmentally hazard-
ous coal waste diminished by citric acid.” What’s intriguing is that, for years now, I’ve been trying
to find definitive information about whether fly ash is a safe additive for concrete and other building
products such as porous pavers or cement board. It matters, because fly ash is plentiful, relatively
inexpensive and when used in place of cement, actually results in a slightly harder concrete.
I’ve assigned freelancers to dig into the topic too, with mixed results. We’ve been told by industry
experts that there’s no definitive measure of just how many heavy metals and other toxins remain in
the post-industrial residue left behind from burning coal — and every batch is different.
But concerns about leaching and human health after contact with fly ash linger. It turns out that
A these concerns are not unfounded. The study I mentioned touts the performance of a new citrus-
based additive. This solvent removed about 42 percent
0.60 of the rare earth metals found in a test batch of what the
author refers to as the “environmental pariah” — coal
0.55
Sandia technology: ash (of which fly ash is a part). The more typical method
0.50 SCCO2 + H2O + Citric Acid used to achieve the same goal involves nitric, sulfuric
or phosphoric acids, which “leave the environment in
0.45 worse shape than before.” And they only remove about
half as much of the bad stuff.
0.40
But entities such as Sandia National Laboratories,
0.35 which sponsored this research, want those metals for
their fighter jets, submarines and other military indus-
0.30 trial complex profit centers. Sandia also plays a large
0.25 role in America’s nuclear arsenal. Is it cynical to sug-
gest that the company’s interest in cleaning up coal ash
0.20 has less to do with sustainability, and more to do with
Existing extraction method: selling drones, missiles and surveillance?
0.15 concentrated HNO3 + H2O2
Some of you will say, “What does it matter WHY
0.10 they’re doing it?” I understand that viewpoint. Ulti-
Sc La Ce Pr Nd Sm Eu Gd Tb Dy Ho Y Er Tm Yb Lu mately, the research may unlock fly ash as a resource,
Fig 1. Comparison of extraction efficiency between Sandia’s environmentally reducing the vast footprint of cement, which is respon-
benign technology and existing method using strong acids—concentrated ntiric sible for about 8 percent of the world’s CO2. On the
other hand, the U.S. military and its hired con-
acid and hydrogen peroxide. SOURCE: SANDIA NATIONAL LABORATORIES
tractors currently rank among the world’s
biggest polluters. Will the gains in cement zero out the additional CO2 released by future bombs and
hardware made possible by rare metals?
Fly ash offers just one example of why it’s so hard to make real change in the status quo of Climate
Change. Why did it take 10 years to find a less-intensive way to clean fly ash? Where were government
regulators in solving the problem? Were they simply underfunded, or uninterested?
It’s great that private industry may solve the problem of toxicity, but the impetus for change shouldn’t
arise from the material needs of bomb makers. That’s a low bar at best, with a net ecological gain that’s
clouded by entanglement. Let’s put technology together with the public interest for a change. Let’s put
our tax dollars to work directly on solving ecological problems, not subsidize military contractors
to “solve” them for us. The computing power and tools are widely available. We can look at com- Matt Power
plex data and weigh cost-benefit, just like the “big guns” do. Unless we look at the Climate Change Editor-in-Chief
problem with full transparency and neutrality, we may never escape our current downward spiral matt.power@greenbuildermedia.com
toward self-induced oblivion. GB

2 GREEN BUILDER November/December 2021 www.greenbuildermedia.com