Edward J. Griffith

THE CHEMICAL AND PHYSICAL PROPERTIES OF CONDENSED PHOSPHATES

ABSTRACT In the following work the current status of inorganic phosphate chemistry is discussed briefly. The influence of phase transitions upon the physical properties of condensed phosphates is reviewed and new data for the 54°C transition of Na 4 P 4 O 12 ·4H 2 O are presented. Urea will prevent the decomposition of Na 5 P 3 O 10 during the transition of Na 5 P 3 O 10 ·6H 2 O to Na 5 P 3 O 10 . The mechanism of this action is discussed. The growths of cleavage families resulting from the hydrolytic degradation of condensed phosphates are discussed, and published rate constants are employed to calculate the growth of families of phosphates.

Scale-Up from Laboratory to Plant

Very often scale-up from laboratory to pilot plant or full-size manufacturing plant can present many challenges that are not easily resolved. It is in this domain that chemical engineers make their greatest contribution to new progress. Chemists, more than engineers, are inclined to be artistic rather than practical. They often build art-forms of science for the archives rather than useful products for the everyday world. (I take license in this statement because I am a chemist and not an engineer.)

Fibers, Phosphates, and Public Protection

This book tells, in the simplest terms the author is capable of writing, the day-to-day experiences of a group of dedicated scientists. Their mission was to bring to the world a safe, inexpensive, mineral fiber that everyone could use without fear. It also teaches the background science and engineering required to bring this project to a technical success, only to have the project abandoned as a direct result of its initial reason for existing. Societies worldwide have become so afraid of “asbestos” that any mineral replacement for “asbestos” is viewed as potentially harmful, and is usually attacked immediately after it is announced.

The Future of Phosphate Fibers

The future of phosphate fibers should be very bright when the patents on the composition expire in 1999. In the author’s mind there has never been a safety issue with phosphate fibers or any other inorganic phosphate that does not contain a toxic cationic or anionic function. Phosphates such as sodium, potassium, calcium, magnesium, ammonium, and hydrogen have never caused a problem of any type with perhaps the exception of renal stones. In this case it may be more of a condition than the cause of a condition. Urine is known to be saturated with respect to calcium phosphates. Some threshold agent or other mechanism that is poorly understood keeps kidneys from becoming completely calcified even in the healthiest of persons.

Melts and Phases

The first requirement for anyone wishing to make significant contributions to the science of new condensed inorganic phosphates is some understanding of phase chemistry. It is not required that phase chemistry be an end in itself, as with those who are interested in the science of phase thermodynamics as an independent study. Some treatises dealing with phase chemistry are all but incomprehensible to those of us who are interested in using diagrams as tools, but not a life’s study.1 Although I have used and studied phase diagrams for most of a lifetime, I make no pretense of being an accomplished master of all aspects of this science. In phosphate chemistry, as I practice it, phase chemistry is an indispensable tool.

The Limiting Element for Life on Earth

It is the purpose of this chapter to furnish a background for understanding the indispensable nature of inorganic phosphates in life processes. If there were no phosphates, there would be no food for our food chain. It is self-evident that phosphates have been compatible with life for hundreds of millions of years. Their compatibility with life and life nurturing qualities make them ideal substances from which to manufacture fibers and other materials of commerce. We have no reasons to fear them.

Product Safety in the Climate that Phosphate Fibers Were Introduced: How Much Testing Is Enough?

It has been my steadfast conviction from the time I first conceived of phosphate fibers that they are a product that requires no toxicological study. This is the driving force that caused me to initiate the project in the first place. If the fibers are not obviously safe, it made no sense to begin a project. Fibers of phosphate are not new and have been used in all manner of household and industrial products for several lifetimes. They have never caused any toxic problems for people, animals, or vegetation. Literature mentions were made that many phosphates were fibrous and resemble chrysotile in appearance. No use had ever been made of their fiber properties. As long as they were merely being eaten, drunk, and inhaled, no notice was taken of the fact that they were fibrous. It was only when they were to become a safe replacement for “asbestos” that their safety was questioned. The same is true again today; we continue to eat, drink, and breathe phosphates and no one questions their safety.

General Phosphate Chemistry (As Applied to Fibers)

General inorganic phosphate chemistry is reviewed in this chapter. Both theory and practice are covered in some detail as a background for controlling both properties and formation of condensed phosphates. Particular attention will be directed toward the necessary constraints required to grow very long polyphosphate anions resulting in long strong phosphate fibers. Much of the work to follow will refer to this chapter. The old established chemistry and some very recent chemistry that is yet too new to judge its long term value is presented.

The Many Uses of Phosphates and Fibers

Almost every week several callers the world over inquire as to sources of phosphate fibers. They ask, “Are you manufacturing this product? Is anyone, anywhere, manufacturing this product?” Regretfully, I must tell them that I know of no commercial source of the fibers. Response to this product has been very rewarding to me, as an inventor. Monsanto’s management made a decision not to manufacture the product and to allow their patent estate to lapse, rather than pay annual fees required to keep the estate active. The problems with potential lawsuits are ever present.