Phosphate rock mining

Phosphorus [7723-14-0] is a nonmetaUic element having widespread occurrence in nature as phosphate compounds (see Phosphoric acid and phosphates). Fluorapatite [1306-03-4], Ca F(P0 2> is the primary mineral in phosphate rock ores from which useful phosphoms compounds (qv) ate produced. The recovery from the ore into commercial chemicals is accompHshed by two routes the electric furnace process, which yields elemental phosphoms and the wet acid process, which generates phosphoric acid. The former is discussed herein (see Furnaces, electric). Less than 10% of the phosphate rock mined in the world is processed in electric furnaces. Over 90% is processed by the wet process, used primarily to make fertilisers (qv). 

Phosphate rock, mined widely throughout the world for its fertilizer value (see Fertilizers), in certain regions contains a few percent of lanthanides. For example, the apatite deposits in the Kola peninsula on the Russian/Finnish border. The Ln content is recoverable from the various processing residues, and because other Ln-containing minerals, such as loparite [12173-83-0], are also found there, the location suppHes a significant part of the demand in Eastern Europe. 

The major sources of TT3PO4 traditionally have been mineral deposits of phosphate rock. Mining operations are extensive in a number of locations, including the United States (Florida), the Mediterranean area, and Russia, among others. The major constituent of most phosphate rocks is fluorapatite, 3Cai(P04)2 CaF>. The supply of high-grade phosphates,... 

The World s Production of Phosphate Rock.—The amounts of phosphate rock mined annually increased only slowly from the beginnings of the industry in 1847 to 250,000 tons in 1869, then to about one million tons in 1887 and about seven million tons in 1918. 

Phosphate rock mining/production of phosphoric acid Gold mines Tin mines... 

Phosphorus (0.11% of the lithosphere) is found mainly in minerals based on calcium phosphate, collophanite, the monohydrate, Ca3(P04)2.H20, and apatite, CagF(P04)3. About 90% of the phosphate rock mined is converted into fertilisers, the rest is used for making elementary phosphorus, phosphorus compounds and such alloys as phosphor bronze. For fertilisers rock phosphate is finely ground and treated with sufficient concentrated sulphuric acid to convert it to the soluble dihydrogen phosphate ... 

More than 85 percent of phosphate rock mined in the United States comes from North Carolina and Florida. Smaller amounts are also mined in Idaho and Utah. Other major producers of phosphate rock are Morroco and Western Sahara, Russia, Tunisia, Brazil, Jordan, Syria, Israel, Egypt, South Africa, and Australia. 

In 2008, more than 95 percent of all the phosphate rock mined in the United States was used in the manufacture of fertilizer and animal feed supplements. Modern farmers use enormous amounts of synthetic (artificial) fertilizer on their crops. This synthetic fertilizer contains nitrogen, phosphorus, and potassium, the three elements critical to growing plants. These elements normally occur in the soil, but may not be present in large enough amounts. Adding them by means of synthetic fertilizer helps plants grow better. Most farmers add some form of synthetic fertilizer to their fields every year. This demand for synthetic fertilizers accounts for the major use of phosphorus compounds. 

Figure 13 shows an Australian example of industrial ecology. Sulfur dioxide is emitted from the metallurgical smelting of sulfide minerals at Mt. Isa in a remote area of Queensland. For many years, large quantities of SO2 had been emitted to the atmosphere. The development of phosphate rock mining at Phosphate Hill some 150 km away provided an opportunity to capture SO2 and convert it to sulfuric acid. The sulfuric acid could be used to digest the phosphate rock to make phosphoric acid. Ammonia manufacture from natural gas was possible, since natural gas from the Cooper Basin held in central... 

A typical phosphogypsum composition is shown in Table 12. The results in Table 12 were from the analyses of the core samples, excluding Samples C2, D, and I. The core for Sample C2 was taken from part of a phosphogypsum stack that had been placed in a phosphate rock mined-oui area. The base of... 

Domestic supplies of vanadium are obtained from a deposit in Arkansas that is mined for vanadium alone from some deposits in the western states that yield coproduct uranium and vanadium and from slags derived from making elemental phosphorus from phosphate rock mined in Idaho. The vanadium-production potential of these deposits does not appear to be adequate to satisfy long-range domestic requirements. 

Underground Methods - There are several underground phosphate rock mining operations in the world and, just as with surface mining, the methods used range from labor intensive to highly mechanized. 

Case studies by IFDC of small-scale phosphate rock mining and production in many developing countries have indicated production costs from about US 25/ tonne to several hundred dollars per tonne. At the lower costs, almost invariably the mining and production equipment and initial technical expertise were donated. At the higher costs, typically the operations were established and/or subsidized by a host government or aid organization however, capacity was severely underutilized. 

In addition to the factors outlined above, any economic comparison will be influenced by the overall plan, for example, whether there are coexisting phosphoric acid or ammonia production facilities and whether the plant is located adjacent to a phosphate rock mine. 

Phosphate rock mining, beneficiation (i.e., processes whereby extracted ore from mining is separated into mineral and gangue),... 

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