How to Crystallize Tons of Melt

Even before engineers were requested for help, all manner of schemes were proposed for potential ways to overcome corrosion and methods to remove a charge from processing equipment, when a melt had crystallized in a vessel, making itself a part of the container walls. One suggestion was that a large hole be dug into an 

Before much engineering work was needed, it was required that a product be defined. There were several candidates. Two leading candidates were calcium polyphosphate and sodium calcium polyphosphates. Calcium polyphosphate was more difficult to make. There was probably no way that a product of this type could be made without heating raw materials to a clear melt at temperatures near 900 °C. Yields were not as high as with sodium calcium polyphosphate. An overriding property of calcium polyphosphate, making it a poor second choice, was its irritating prickly nature. 

One young chemist was heard to say, If I wanted to torture a person, I would strip him and lock him in a room of calcium polyphosphate fibers. His point was well taken and this problem has never been solved, but it probably could be solved in a relatively short period of time. It should be emphasized that only [Ca(P03)2]n fibers, and not [NaCa(P03)3] , were irritating. Not all batches of [Ca(P03)2]n fibers were irritating. This alone is evidence that this problem can be eliminated. It is merely a matter of knowing which variables must be controlled. Some work 

Not only the containment problem was difficult with calcium polyphosphate melts, but leaching and fiber opening were also involved. Separation problems of leachate solubles were certain to be difficult engineering challenges. It would be necessary to recapture dissolved phosphate in leach water before it could be recycled. The cost of phosphate in leach water was too expensive to consider it as waste and recycling was to be expensive also. 

As problems were identified, solutions would arise almost as if by magic. Nevertheless, it was obvious that calcium polyphosphate fiber could never be commercialized as a commodity product using this process. It still has some very interesting properties for specialties where price is not a major issue. Some medical uses could fall in this area. Abe s work in Japan has concentrated on this particular compound and some outstanding results have been obtained. 

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