As we earlier reported, and as now accessible on the West Virginia Coal Association's web site via:
Leftover Gets a Makeover: Professor Develops a New Use for Coal Ash | Research & Development; wherein we learn that:
"An assistant professor in Georgia Tech’s School of Civil and Environmental Engineering, Professor Mulalo Doyoyo, has developed a new structural material based on (the) leftovers from coal burning. Known as Cenocell, the material offers attributes that include high strength and light weight – without the use of cement, an essential ingredient of conventional concrete";
one of the common ingredients in Coal Ash are tiny, hollow "microspheres", known in the trade as "Cenospheres", composed of what are labeled "aluminosilicate" compounds.
Due to their chemical composition, and like the bulk of Coal Ash, they can be used as a reactive filler in conventional Portland cement, and concrete made from that cement, to which compositions they impart some special properties, in addition to those imparted by regular Coal Ash, including most especially lighter weight and increased insulation value.
Concerning the above, and as we've documented in a number of other reports, such as:
US Government Coal Ash Cement Stronger than Portland Cement | Research & Development; concerning, primarily:"United States Patent 4,256,504 - Fly Ash-based Cement; 1981; Assignee: The United States of America (as represented by the Secretary of the Interior); Abstract: A cement composition comprising a high calcium-content fly ash and calcium sulfate, and mortar and concrete compositions containing the cement";
the use of Coal Fly Ash as one of the components of cement can, as well, make the concrete resulting from that cement stronger than that made with conventional Portland cement.
That is because, as we've also documented previously, Coal Ash acts as a "pozzolan", a term evolving from an area in Italy where volcanic ash was originally used for the purpose, and, which, as can be learned via:
Pozzolan - Wikipedia, the free encyclopedia;
when added "to Portland cement concrete mixtures" serves "to increase the long-term strength and other material properties of Portland cement concrete, and in some cases reduce the material cost of concrete".
The value of the Cenospheres, relative to the bulk of Coal Ash, lies in the fact that, physically, they are spherical, or roughly spherical, hollow "bubbles" of the same aluminosilicate minerals present in Coal Ash.
They thus represent relatively strong and rigid, though light weight, particles, with intrinsic insulating properties.
And, their specific value has been recognized by our United States Government, since, as they officially record the fact, the University of Kentucky has expended some effort to figure out ways in which the Cenospheres could be extracted from the bulk of the Coal Ash material, as seen in:
http://www.netl.doe.gov/
The University of Kentucky does provide some technical data concerning the efficiencies of various Cenosphere harvesting techniques, and urges that more work be done to improve those techniques, since the effort, given the potentials for utilization of the Cenospheres, would seem to be worth it.
As we will see in coming reports, that effort has already been, successfully, made in other parts of the world, and Coal Ash Cenosperes are becoming, again in other, surprising, parts of the world, a desirable product.
But, herein, we submit, with comment inserted and appended, as excerpted from the initial link in this dispatch, the recently-issued United States Patent awarded to Georgia Tech's Mulalo Doyoyo, for the use of Coal Ash Cenospheres:
"United States Patent 8,057,594 - High Strength Pozzolan Foam Materials and Methods of Making Same
Date: November, 2011
Inventors: Mulalo Doyoyo, et. al., US and France
Assignee: Georgia Tech Research Corporation, Atlanta, GA
Abstract: The various embodiments of the present invention relate generally to high strength foam materials and methods of making the same. More particularly, various embodiments of the present invention relate to high strength foam materials comprising pozzolans, such as cenospheres derived from fly ash. An embodiment of the present invention comprises, a pozzolan foam material comprising a pozzolan, an alkali, a silicate, and an organosilicon compound. Various embodiments of the present invention are directed to strong, lightweight materials that are environmentally-friendly and can be economically manufactured.
Claims: A pozzolan foam material, comprising: a pozzolan in an amount ranging from about 50% to about 95%, an organosilicon compound ... , an alkali hydroxide ... , and a silicate ... .
The pozzolan foam material ... wherein the pozzolan comprises a plurality of cenospheres.
The method of making a pozzolan foam material ... further comprising prior to step curing the mixture to form a pozzolan foam material, forming the mixture into an article, wherein the step of curing the mixture to form a pozzolan foam material comprises curing the article to form an article comprising a pozzolan foam material.
Background and Field: The various embodiments of the present invention relate generally to high strength foam materials and methods of making the same. More particularly, various embodiments of the present invention relate to high strength foam materials comprising pozzolans and an organosilicon compound.
Enormous amounts of ash are produced in the generation of electricity using black coal-fired burners. Fly ash is generally captured from the chimneys of power generation facilities, whereas bottom ash, as the name suggests, is removed from the bottom of the furnace. In the past, fly ash was generally released into the atmosphere, but pollution control equipment permits the capture of fly ash, preventing its entrance into the atmosphere ... .
One component of fly ash is cenospheres, which are spherical inorganic hollow microparticles comprising the lightest component of fly ash. Cenospheres typically comprise approximately 1%-2% of fly ash and can be recovered or "harvested" from fly ash.
(Don't be discouraged by the low percentage of "Cenospheres" contained in Coal Ash. They are a relatively high-value product that are worth physically extracting. But, once they are extracted, the chemical composition of the bulk of the Coal Ash remains unchanged; and, that remaining bulk of Coal Ash can still be further utilized in other technologies, such as that described in our report of:
Pittsburgh Converts Coal Ash and Flue Gas into Cement | Research & Development; concerning: "United States Patent 5,766,339 - Producing Cement from a Flue Gas Desulfurization Waste; 1998; Dravo Lime Company, Pittsburgh; Abstract: Cement is produced by forming a moist mixture of a flue gas desulfurization process waste product (and) a source of aluminum, iron, carbon, and a siliceous material (and) wherein said source of aluminum and iron comprises fly ash";
and, be converted, with "flue gas desulfurization" scrubber sludge, for instance, into a perfectly-acceptable, and much more environmentally-friendly,
The recycling of fly ash has become an increasing concern in recent years due to increasing landfill costs and current interest in sustainable development (and, recycling) fly ash provides other environmental benefits, such as reducing the demand for virgin materials that would need quarrying and substituting for materials that may be energy-intensive to create (e.g., Portland cement).
There is currently a great demand for strong and lightweight materials that are easily and economically manufactured. Such materials have long been sought by the construction and automotive industries to increase the strength, durability, and resilience of structures while reducing the weight of the structure. In the context of the construction industry, such materials can make buildings more resistant to natural disasters (e.g., earthquakes), whereas strong, lightweight materials can reduce the energy consumption of an automobile. In addition, there is a demand for porous materials as they can act as sound or thermal insulators and as shock absorbers. However, presently available materials that meet these criteria, such as metallic foams, are very expensive. Furthermore, there is a great demand for environmentally-friendly "green" materials.
Accordingly, there is a need for strong and lightweight materials that are environmentally-friendly and can be manufactured economically. It is to the provision of such materials that the various embodiments of the present invention are directed.
Summary: Various embodiments of the present invention are directed to high strength pozzolan foam materials and methods of making the same. More particularly, various embodiments of the present invention comprise a pozzolan foam material comprising a pozzolan and an organosilicon compound. In an embodiment of the present invention, a pozzolan foam material can further comprise an alkali and a silicate. The pozzolan can comprise an aluminosilicous material. In an embodiment of the present invention, an aluminosilicous material can comprise a plurality of cenospheres. The pozzolan of the pozzolan foam material can comprise about 50% to about 90% of the foam material. In an embodiment of the present invention, the pozzolan foam material can comprise a foam-induced porosity of about 0% to about 30%.
In an embodiment of the present invention, the alkali can comprise ... sodium hydroxide, calcium hydroxide, potassium hydroxide, and magnesium hydroxide. In an embodiment of the present invention, the silicate can comprise ... sodium silicate. In an embodiment of the present invention, the organosilicon compound can comprise dimethylsiloxane.
(In other words, nothing very expensive, in addition to the Coal Ash Cenospheres, is needed.)
A pozzolan foam material can further comprise one or more of gravel, sand, soil, stone, pigment, calcined soil, Portland cement, limestone, gypsum, concrete, mortar, and grout.
In an embodiment of the present invention, the plurality of cenospheres can comprise about 50% to about 90% of the foam material.
(In other words, we can make some useful stuff, more than half of which consists of a product extracted from Coal Fly Ash.)
In an embodiment of the present invention, a method of making a pozzolan foam material can further comprise prior to step curing the mixture to form a pozzolan foam material, forming the mixture into an article, wherein the ... article can comprise a building element."
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The full Disclosure goes on at quite some considerable, and complicated, length describing the ways and means by which Coal Ash Cenospheres can be advantageously utilized, in admixture with various other materials, in the manufacture of various other products; which other products have a number of, some not that obvious, potential applications.
Of most interest, though, we think, should be their use in admixture with, as specified herein by Georgia Tech, "Portland cement, ... concrete, mortar, and grout", especially since, as seen in our above citation of ""United States Patent 5,766,339", the "cement" itself can actually be made from the other, remaining constituents of Coal Ash.
And, somewhat unsurprisingly, just as with the truth that Coal can be economically converted into various and more versatile forms of liquid and gaseous hydrocarbons; which is openly acknowledged and recognized, as seen in:
China Celebrates Coal Liquefaction | Research & Development; concerning: "The World CTL 2012 Conference takes place on April 17-20, 2012 in China, featuring two World Best: The reference gathering of Coal Conversion experts and managers on April 17-19 in Beijing (and) the visit to the World’s Largest Coal-To-Olefins Plant on April 20 in Baotou (Inner Mongolia)"; and, in:
South Africa 100% Coal Conversion | Research & Development; concerning: "United States Patent 4,251,346 - Process for Coal Liquefaction; 1981; Assignee: SASOL One (South Africa); Abstract: The invention provides a process for the liquefaction of coal (which) can be controlled so that the coal is converted virtually completely into distillable products";
in some other, less-than-mainstream, parts of the world; the fact that Cenospheres, as extracted from Coal Ash, have great commercial value as a specialty construction material is recognized, too, and commercially exploited, in some relatively out-of-the-way, and unlikely, places; as we will document in reports to follow.
In any case, again, as demonstrated herein, even the solid residues remaining from our vital, even essential, use of Coal for the generation of electrical power have valuable commercial utility.
We need to stop letting ourselves be deceived into thinking, and acting, as if they are some sort of poisonous waste we must, at great expense to our vital Coal-use industries, and their customers, find some way acceptable to the vocal, and from our point of view now suspect, critics of Coal, to dispose of.
Like Carbon Dioxide, as seen, for just one example, in our report of:
Conoco Converts CO2 to Methanol and Dimethyl Ether | Research & Development; concerning: "United States Patent 6,664,207 - Catalyst for Converting Carbon Dioxide to Oxygenates; 2003; Assignee: ConocoPhillips Company, Houston; Abstract: A catalyst and process for converting carbon dioxide into oxygenates (such as) methanol and dimethyl ether";
our Coal Ash is a Coal Utilization Byproduct of potentially-great value.
We should start focusing our attention on the ways in which the United States citizens of United States Coal Country can start receiving some benefit from that value.