nsf.gov - Engineering (ENG) News - Follow the "Green" Brick Road? - US National Science Foundation (NSF)

This will be a lengthy dispatch. But, since legislation introduced by West Virginia's congressional contingent, intended to prevent the EPA from arbitrarily classifying Coal-fired power plant fly ash as hazardous waste, has passed the House of Representatives and been introduced to the Senate by West Virginia's US Senators, it might be worth the read.

We've lately been documenting the fact that solid Coal-use residuals, whether they result from simply burning Coal or from converting Coal into more versatile hydrocarbons, can be used in the manufacture, or supplementation, of "Portland"-type cement and mortar.

We won't cite any of our prior reports concerning that fact, since more are reports are in process demonstrating, as does this one, some of the, perhaps surprising, certainly not obvious, additional ecologic and economic benefits that could accrue from such usage.

As we've also reported, for one instance, in:

Carbon Dioxide + Coal Fly Ash = Synthetic Lumber | Research & Development; concerning, in part: "United States Patent Application 20080029925 - Filled Polymer Composite and Synthetic Building Material; 2008; Inventor: Wade Brown, FL; Abstract: The invention relates to composite compositions having a matrix of polymer networks and dispersed phases of particulate or fibrous materials. The matrix is filled with a particulate phase, which can be selected from one or more of a variety of components, such as fly ash particles ... . A method of continuously forming a molded material comprising: forming a composite mixture in an extruder, wherein the composite mixture comprises: (polyurethane reaction components, and) about 45 to about 85 weight percent of inorganic particulate material ...; and a catalyst; extruding the mixture through a die; and molding the mixture into a shaped article. (And) wherein the shaped article is a building material (such as) lumber (or) roofing (or) siding";

Coal fly ash can be utilized as a reinforcing, and cost reducing, "filler" for certain types of plastic, making the plastic suitable as a material from which we can fabricate various articles of construction which might otherwise demand the use of wood.

We'll note in passing that such applications are not necessarily just a "cheapening" of the plastics, or of the articles made of plastic. It is standard, common manufacturing practice to "fill" plastic resins of various types with one sort of chemically inert material or another. Such practice not only makes the plastic item more affordable, it often makes the plastic item more suitable for specific applications and improves it's strength.

Anyone who has tinkered around trying to repair dents or rust holes or their work trucks with fiber glass mats and resin, and fiber-filled patching compound, will understand. Even auto body putty itself, you can see if you look close at the stuff in the big cans, and anyone out in the sticks whose driven to work at the mine everyday throughout a Coal Country winter has, contains a lot of almost-microscopic "grains", often just ground limestone, that gives the stuff some rigidity when it sets up.

More on the use of Coal fly ash in both plastics and cement will follow in coming reports, but, herein, we document how fly ash can be utilized to great good effect in yet another construction material: Bricks.

First, though, for those not familiar with the differences between Portland-type cement, and various related mortars, and traditional "bricks", some background:

Although, on the face of it, they can, once both are cured and utilized, appear very similar, since they both appear to be some sort of artificial "stone", the processes of how they finally achieve their rock-like status are very different.

In brief: Concrete, or cement, hardens up and gets solid through a chemical reaction between water and the reactive mineral components of the cement. Brick, on the other hand, gets to be what it is by being heated to the point where the minerals of which it was originally made almost, but not quite, "melt" together and are made to react, to re-crystallize as it were, in a process somewhat akin to making alloys of metal.

Traditional brick could be thought of as a kind of ceramic, for anyone having experience with pottery kilns.

But, Coal fly ash can be utilized in an untraditional, lower-temperature and lower-energy way of making bricks, with, as with concrete, some additional and surprising ecological benefits, as we alluded to above, and, as seen in excerpts, with additional links and excerpts to follow, from the initial link in this dispatch to:  .

"Follow the Green Brick Road?

Engineering News; US National Science Foundation

Researchers have found that bricks made from fly ash--fine ash particles captured as waste by coal-fired power plants--may be even safer than predicted. Instead of leaching minute amounts of mercury as some researchers had predicted, the bricks apparently do the reverse, pulling minute amounts of the toxic metal out of ambient air.

Each year, roughly 25 million tons of fly ash from coal-fired power plants are recycled, generally as additives in building materials such as concrete, but 45 million tons go to waste.

Fly ash bricks both find a use for some of that waste and counter the environmental impact from the manufacture of standard bricks.

'Manufacturing clay brick requires kilns fired to high temperatures,' said Henry Liu, a longtime National Science Foundation (NSF) awardee and the president of Freight Pipeline Company (FPC), which developed the bricks. 'That wastes energy, pollutes air and generates greenhouse gases that contribute to global warming. In contrast, fly ash bricks are manufactured at room temperature. They conserve energy, cost less to manufacture, and don't contribute to air pollution or global warming.'

(Note, though we won't reference the fact, "Freight Pipeline Company" has since officially changed it's name to "Ecological Tech Company", as is reflected in the United States Patent included below. - JtM)

Once colored and shaped, the FPC bricks are similar to their clay counterparts, both in appearance and in meeting or exceeding construction-material standards.

Supported by National Science Foundation's Small Business Innovation Research (SBIR) program, Liu has been working since 2004 to develop the bricks. The first phase of support enabled him to make fly ash bricks more durable by engineering them to resist freezing and thawing due to weather. Liu is now working from a second-phase SBIR award to test the brick material's safety and prepare it for market.

While researchers need to study the bricks further to determine how the mercury adsorption occurs and how tightly the metal is trapped, the new findings suggest the bricks will not have a negative impact on indoor air quality.

On average, air contains low amounts of mercury (and, inside) a confined experimental chamber, the bricks did not raise the mercury levels in the surrounding air (but),instead appeared to lower the concentration ... .

Engineers from FPC of Columbia, Mo., developed the bricks with NSF support and reported their findings on mercury leaching at the May 7-10, 2007, World of Coal Ash Conference in Cincinnati, Ohio.

Henry Liu has received a number of NSF awards since 1980 and founded FPC after retiring as professor of civil engineering and director of Capsule Pipeline Research Center, a state/industry university cooperative research center established by NSF at University of Missouri-Columbia in 1991 to research and develop capsule pipeline technology."

We must note, before continuing, that the esteemed Dr. Liu is no longer with us. As seen in:

UPDATE: Inventor and retired MU professor Henry Liu died in crash Tuesday - Columbia Missourian; "The man killed in a single-vehicle crash on Interstate 70 Tuesday was a Columbia engineer and a retired MU professor known for his work in "green" technologies. Henry Liu, 73, was traveling westbound near mile marker 129.6 when his 2003 Toyota SUV veered off the road striking two trees before coming to rest 200 feet off the road. Liu was awarded the $100,000 Purpose Prize award in October 2009 for developing environmentally-friendly bricks from fly ashl. This production method is more efficient and does not contribute to air pollution."He was in the process of making the world a better place with his inventions," said Carla Roberts, Liu's administrative assistant at Freight Pipeline Co. "We plan to continue the projects that he has in motion now"";

he tragically died, if we understand the dates provided by the full article correctly, just slightly less than one year ago.

But, he had, fortunately for us, before his passing, applied for a United States Patent on his technology for utilizing Coal fly ash productively and profitably in the manufacture of brick. And, recently, that application resulted in the posthumous award of:

"United States Patent: 7998268 - Method to Produce Durable Non-vitrified Fly Ash Bricks and Blocks

Date: August, 2011

Inventor: Henry Liu, Missouri

Assignee: Ecological Tech Company, Inc., Columbia, MO

(Again, as noted above, formerly: "Freight Pipeline Company".)

Abstract: A method of making durable, non-vitrified masonry units comprising fly ash, the method comprising mixing fly ash comprising a minimum of 15% Calcium Oxide (CaO) by weight and ... and an air entrainment agent to form a fly ash mixture; compacting the fly ash mixture in a shaping device by applying pressure of at least 1000 psi to the fly ash mixture; and curing the compacted fly ash mixture to cause the mixture to harden and gain strength.

A method to produce durable, non-vitrified masonry units comprising fly ash ... .

(And) wherein the CaO content of the fly ash is adjusted by adding Portland cement, lime, or another fly ash, so that the CaO content of the adjusted fly ash is more than 15% by weight.

(And) wherein the shaping device is a mold (or) an extruder.

(And) wherein the masonry units withstand at least 50 freeze/thaw cycles as determined in accordance with ASTM Standard C62.

(By way of reference, have a look at:

ASTM C62 - 10 Standard Specification for Building Brick (Solid Masonry Units Made From Clay or Shale);

which tells us that: "ASTM C62 - 10 Standard Specification for Building Brick (Solid Masonry Units Made From Clay or Shale) ... covers building bricks intended for use in structural and nonstructural masonry where external appearance is not a requirement. The bricks are prismatic units available in a variety of sizes, shapes, textures, and colors and are manufactured from clay, shale, or similar naturally occurring earthy substances by firing. The heat treatment should develop sufficient fired bond between material particulates to produce a material that conforms to the required strength and durability.")

Description and Background: This patent deals with a new method to produce from fly ash durable (i.e., freeze/thaw resistant) masonry units such as bricks at room temperature, without having to heat the units in kilns at high temperature in order to vitrify the units, as it is required for ordinary masonry units made of clay.

(Note, thus, as above, the implied energy savings. It takes a lot of heat, a lot of energy, perhaps with concomitant emissions of Carbon Dioxide, to "fire" traditional clay bricks. This process might not only save energy while it recycles Coal ash, it might also help to reduce overall Carbon Dioxide emissions.)

This patent application deals with a new technology that uses fly ash to make durable bricks, blocks, and other similar materials--hereafter referred to simply as "bricks"--for construction and other purposes. With this new technology, fly ash mixed with a small amount of water is compacted at room temperature to produce strong and durable bricks and blocks. Unlike the clay bricks which must be heated at high temperature to vitrify the clay, the fly ash bricks and blocks made by this technology need not be heated or vitrified. Hardening of the bricks is accomplished at room temperature by curing, in a way similar to the hardening of concrete products. Consequently, by using the non-vitrified fly ash bricks instead of the vitrified (fired) clay bricks, the fossil fuel used in vitrifying clay bricks and the air pollutant caused by burning the fossil fuel are both avoided, making the non-vitrified fly ash brick technology both energy-efficient and pollution-free. It constitutes the most energy-efficient and environmentally-friendly process of making bricks."


And, these "energy-efficient" Coal fly ash bricks are "environmentally-friendly" not just because they utilize what might otherwise be classified as a "hazardous waste" in need of some sort of disposal, nor because they reduce the overall emissions of Carbon Dioxide in the total, combined electric power-generating and  brick-making  "big picture".

If you're not familiar with how and where we now get clay from which we make bricks, we suggest that you someday take a tour on the back roads of the piney woods in certain areas of our southeastern United States.

There, you will that it is, and has been for a century, strip mined.

And, perhaps because it ain't Coal they're mining, no one, as far as the one-time professional geologist among our number who visited a few brick clay mines back in the eighties could tell, gives much of a hoot about how they go about it.

The only "regulators" that he ever saw or heard of were those wanting to make certain that everyone there was wearing steel-toed boots and hard hats.

The rest of the operations were just bulldozers, end loaders and dump trucks, without even a bag of grass seed lying around to make a token gesture towards restoration.

The infected, festering wound of an old, abandoned clay mine would make the restored terrain of a played-out Coal surface mine look like a park and playground.

So, by using Coal fly ash to make bricks, we might not only cut back on total Carbon Dioxide emissions, and energy consumption in the brick-making industry, while we're more fully utilizing a valuable Coal combustion by-product, we might, too, be reducing the total number of surface mines in operation, especially some surface mines that aren't held, as surface mines extracting Coal are held, to stringent levels of environmental quality and environmental restoration.

And, making bricks - - bricks that, as we documented above, can leach and sequester mercury out the atmosphere - - out of Coal fly ash would, just as, as in:

US Navy Awarded September, 2011, CO2 Recycling Patent | Research & Development; concerning: "United States Patent 8,017,658 - Synthesis of Hydrocarbons via Catalytic Reduction of CO2; 2011; The United States of America as represented by the Secretary of the Navy; A method of: introducing hydrogen and a feed gas containing at least 50 % carbon dioxide into a reactor containing a Fischer-Tropsch catalyst; and heating the hydrogen and carbon dioxide to ... produce hydrocarbons";

making liquid hydrocarbon fuels out of Coal plant exhaust fumes would, not only improve the environment of United States Coal Country, but, the economy of United States Coal Country, as well.

When, can anyone remember, is the last time the beautiful state of West Virginia used the words, except in bitter jest, "full employment"?

West Virginia Coal Association - PO Box 3923 - Charleston, WV 25339 | 304-342-4153 | website developed by brickswithoutstraw