United States Patent: 4268316

In an earlier dispatch, now accessible via:

Coal Fly Ash Bricks are Greener and Stronger | Research & Development; concerning, primarily: "United States Patent 7,998,268 - Method to Produce Durable Non-vitrified Fly Ash Bricks and Blocks; 2011; Assignee: Ecological Tech Company, Inc.; MO; Abstract: A method of making durable, non-vitrified masonry units comprising fly ash";

we documented the practical use of Coal power plant Fly Ash in the making of, essentially, concrete blocks, and, other masonry units that could substitute for vitrified bricks, all of which meet the applicable American Society for Testing and Materials (ASTM) standards for such products.

The use of Coal Fly Ash in such applications offers the potentials for energy, and other, CO2-reducing, economies, since it isn't necessary to, first, generate heat, through the combustion of fuel, to bake, i.e., "vitrify", bricks; and, less limestone, CaCO3, would have to be processed in cement kilns, via the reaction CaCO3 = CaO + CO2, to make conventional, Portland-type cement.

Herein, we see that similar and related economies, and other conservation benefits, as well as improved performance, can be achieved through the use of Coal Fly Ash in the making of the masonry mortar with which those Fly Ash blocks and bricks are laid up.

Comment follows excerpts from the initial link in this dispatch to:

"United States Patent 4,268,316 - Masonry Cement Composition

Date: May, 1981

Inventor: Milton Wills, MD

Assignee: Martin Marietta Corporation, MD

(A complicated interruption is necessary here. The named assignee would now be:

Martin Marietta Materials - producing the construction aggregates that build our world.

And, perhaps, specifically, their "Martin Marietta Aggregates" division, which "is the nation’s second largest producer of construction aggregates in the United States" and "has more than 285 "quarries and distribution facilities in 28 states, the Bahamas and Nova Scotia".

Martin Marietta Materials is a descendent of the more-famed Lockheed-Martin Aerospace high-tech merger, and was spun off from Lockheed Martin almost immediately after that merger, in 1996.

More can be learned via: Martin Marietta Materials - Wikipedia, the free encyclopedia.)

Abstract: A masonry cement is prepared by blending portland cement, kiln dust, and fly ash. The cement of this invention exhibits no efflorescence, good board life, workability, and acceptable color for use with such construction materials as brick, cinder block, and concrete block.

Claims: A masonry cement consisting of from about 25 to about 55 percent portland cement, from about 25 to about 65 percent kiln dust, and from about 10 to about 25 percent fly ash. 

A cement ... wherein said kiln dust comprises cement kiln dust. 

A cement ... wherein said fly ash is produced by the combustion of coal.

(We'll interject here to emphasize the above claim, since "coal", as the source of the Fly Ash, isn't mentioned again; and, since the bulk of the Disclosure is given over primarily to exposition of how the properties of such mortar, as supplemented with Coal Fly Ash, are superior to those of more conventional mortar compositions.)

Background: The present invention is related to a masonry cement having improved characteristics and reduced limestone content, utilizing materials such as kiln dust and fly ash, which would otherwise constitute waste products. More broadly, this invention relates to hydraulic cement mixes, for example hydraulic cement concretes, mortars, and grouts, neat cement mixes, non-plastic cement or concrete mixes, such as concrete block mixes, and dry mixes for making such concretes, mortars, and grouts.

It is an object of the present invention to produce high strength mortar of improved workability and increased water retention while simultaneously eliminating the use of limestone as a filler. 

It is another object of the invention to provide a process for increasing the strength of mortar without undue retardation of the rate of set and early strength. It is another object of the invention to provide a hydraulic cement mix having enhanced compressive strength and reduced water requirements for a given plasticity, together with an acceptable rate of set. It is a further object of this invention to provide a material of construction having essentially no efflorescence, and acceptable compressive strength and rate of set. 

It is a further object of the invention to provide a means of utilization of kiln dust and fly ash, normally considered waste products. In this manner, the manufacture of cement is less energy intensive since it is blended rather than interground. 

It is another object of this invention to provide an improved cement composition for use in grout or neat cement mixes, mortar mixes, or concrete mixes and similar mixes adapted for use as toppings, patches and other mixes where and high early strength is necessary or desirable. 

Still another object of the invention is to provide hydraulic cement compositions comprising of cement, kiln dust and fly ash, either with or without aggregate material or ready mixes which can be dry-packaged and which provide, when mixed with water, setting times and early compressive strengths which adapt the compositions or ready mixes for use as a grout, mortar or concrete where high early strength development is necessary or desirable.

Summary: In accordance with the invention, a masonry cement is prepared which consists essentially of Type I cement (i.e. portland cement), fly ash, and kiln dust. This cement demonstrates complete compliance with ASTM Specification C 91 for Masonry Cement. Preferred compositions comprise from 50 to 60 percent portland cement, from 25 to 40 percent kiln dust, and from 10 to 25 percent fly ash.

The cements of the present invention thus demonstrate suitable properties for masonry use, and exceed the requirements of the applicable ASTM standards.

The invention also provides for consumption of waste ... and provides increased finished mill production, since the proposed masonry cement can be blended rather than interground with clinker and limestone, which conserves energy.

In addition, an extension of quarry reserves is envisioned, since limestone will be eliminated from the masonry product. The cement readily provides an option for the production of block cement ... as well as an option to produce a type IP Cement (ASTM C595) where fly ash is available."

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Anyone know where we might have a little "fly ash ... available"?

If we do have any old, unwanted Fly Ash lying around, then we could, as herein, begin using up a little bit of it to manufacture a higher-performance mortar for cement blocks and bricks, which themselves, as in the process of "United States Patent 7,998,268 - Method to Produce Durable Non-vitrified Fly Ash Bricks and Blocks", cited above, could be made in large part from Coal Fly Ash.

Taken together, those two, productive uses for the recycling of what some see as a noxious waste, could provide the multiple benefits of waste recycling, overall reductions in CO2 emissions, and, although not reflected well in our excerpts but specified in the full Disclosure, improvements in the performance of masonry structures laid up and built with masonry cement composed in part of Coal Fly Ash; a masonry cement whose properties and performance "exceed the" currently established "requirements".

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