3 edition of Assessment of Phosphogypsum as A Constituent of Aggregate Material. found in the catalog.
Assessment of Phosphogypsum as A Constituent of Aggregate Material.
United States. Bureau of Mines.
|Series||Report of investigations (United States. Bureau of Mines) -- 8939|
|Contributions||May, A., Cobble, J., Sweeney, J.|
November Kennedy and Francis K. Description: "This report summarizes the findings of a 9-yr research program, sponsored by the U. The gypsum slurry is pumped wOne metric ton MT is approximately 1.
Thus, most of the radium follows the phosphogypsum in the wet process, while most of the uranium and thorium are in the phosphoric acid product. Abdel-Aall, University of Florida. Thirty-six castable or gunnable refractories and cements and 24 refractory brick were evaluated. A number of chemical elements are required to support vigorous plant growth. Although gypsum is a widely used material in the construction industryphosphogypsum is usually not used, but is stored indefinitely because of its weak radioactivity.
There are currently about 1 billion tons of phosphogypsum stacked in 25 stacks in Florida 22 are in central Florida and about 30 million new tons are generated each year. There are approximately five tons of phosphogypsum produced for every ton of phosphoric acid produced. Kennedy and Francis K. Phosphogypsum Stack Gardinier W. The radium that is found naturally associated with phosphate rock becomes associated with the phosphogypsum after the rock is reacted with sulfuric acid. This byproduct material, filtered from the phosphoric acid, is transferred as a water slurry to open air storage areas known as stacks.
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Gallardo, and Barbara B. Sumpter, Melissa Derby, Maria T. Total accumulations of phosphogypsum are well in excess of million metric tons million tons and are expected to approach million metric tons 1 billion tons by the year The physical treatment was based on the particle size separation dry and wet fractionationwhereas the chemical treatment was carried out using leaching solutions single and sequential leaching processes.
The phosphogypsum stacks ranged in area from approximately 5 to almost acres, and heights of the stacks ranged from 3 to about 60 meters. There are approximately five tons of phosphogypsum produced for every ton of phosphoric acid produced. United States. As a result, phosphogypsum which exceeds this limit is stored in large stacks.
The major phosphorus materials in the rock are geologically in the apatite group, which in high grade ores is about seventy percent calcium phosphate and is mixed with a large number of impurities, such as calcium fluoride, chlorides, chromium, rare earths, and radionuclides.
The phosphate rock is recovered by open pit mining. Fluorogypsum Recycling Fluorogypsum is not being used in any commercial applications; however, fluorogypsum has been evaluated for use as a road base material. Gypsum is dredged from the pond on top of the stack and used to increase the height of the dike surrounding the pond.
A stack was classified as idle if there were definite plans to reactivate it and it has the characteristics of an active stack, e.
These conditions were the result of low domestic demand and reduced foreign purchases EPA The location and characteristics States EPA89a. The values of pH and pCa suspensions of gypsum binders can serve as design criteria for innovative multiphase gypsum binders.
Royster Royster Seminole Pert. It is uncertain which of the above processes are used by each of the phosphoric acid facilities; however, indications are that only two or three facilities use one of the processes which generate the hemihydrate phosphogypsum while the large majority of the facilities use one of the processes which generate the dihydrate phosphogypsum EPA The material is arranged as shown in the following descriptions of the chapters and appendices.
Grace Royster Conserv Estech a. Cedar Holding Co. As a result, the market for the phosphogypsum generated by the chemical processing of phosphate rock has been limited. When the waiver expired on October 1,all persons holding stacks of phosphogypsum became subject to the work practice requirements in subpart R.
America is blessed with abundant, low-cost natural gypsum. Department of Energy and conducted by the Bureau of Mines, to evaluate refractory liner materials for coal gasifier reactors. Economic analysis on the construction of the experimental roads conducted by the University of Miami, indicated tremendous saving on the construction cost of utilizing phosphogypsum as compared to the traditional method of construction.To conveniently discuss common amounts of radioactivity – such as that associated with phosphogypsum – we often talk in terms of picocuries (pCi).
A picocurie is one trillionth of a curie. The activity is then related to a given mass or volume of material, such as a liter or a gram, depending on whether the material is liquid, solid or gas. «Back. Use of Florida Phosphogypsum in Synthetic Construction Aggregate.
Final. In its role to provide technology to promote the efficient use of minerals and mineral process waste, the U.S. Bureau of Mines has conducted research to identify and develop high volume uses for phosphogypsum.
The output of waste materials suitable as cement replacement (slags, fly ashes, silica fumes, rice husk ash, etc.) is more than double that of cement production.
These waste materials can partly be used, or processed, to produce materials suitable as aggregates or fillers in concrete. The physico-chemical characterization of Brazilian phosphogypsum showed that some phosphogypsum, the group 2, may be used as building materials.
The thoron levels are high in Brazilian phosphogypsum. material is developed the important question of product demand remains an open one. The study of a new product demand can start by determining what traditional products substitute for recycled materials.
Recycled phosphogypsum based materials are believed to be substitutes for traditional construction material such asAuthor: Alicia Norma Rambaldi. Admixtures of phosphogypsum, fly ash, and lime that could produce a coarse aggregate suitable for road construction were investigated.
Using phosphogypsum with asphalt, cement, cement-kiln dust, silica, clays, and oxychlorides to produce aggregate was also examined.