World reserves

Although estimated world reserves of shale are very high and shales contain other potentially useful materials, oil production has,... 

Some molybdenum contain from 0.002% to 0.2% rhenium. More than 150,000 troy ounces of rhenium are now being produced yearly in the United States. The total estimated Free World reserve of rhenium metal is 3500 tons. Rhenium metal is prepared by reducing ammonium perrhentate with hydrogen at elevated temperatures. 

Table 14. World Reserves and Resources of Phosphate Rock ...

At the present rate of world phosphate rock consumption (150 x 10 t/yr), the total world reserve (Table 14) is sufficient for about 200 years, and the resource would be sufficient for nearly 900 years. At expected increased rates of consumption, the reserves and resources are adequate for at least 150 years and 700 years, respectively. At projected rates of consumption, the high grade reserves in Florida probably will be exhausted by the year 2000. Rock production from the Florida reserve presentiy constitutes about 80% of all United States production and about one-third of world production (106). This rate of depletion is causing increased interest in western United States reserves which represent nearly 80% of present U.S. total reserves. 

In addition to the indicated total world reserves of about 21 x 10 t having P2 s content of at least 30%, and the 9.1 x 10 ° t classified as resources, there are about 250 x 10 t of reserves and resources derived from guano which are not included in Table 14. 

An assessment of world potash resources (108) is shown in Table 15. Of the 67 x 10 t of total estimated reserves and resources in Canada, nearly 5 X 10 t is recoverable by conventional mining methods and the remainder by solution mining. As of 1974, Canada had about half of the known world reserves and about 90% of known world resources of potassium. 

Iron. World reserves are placed at 236 x 10 t of ore containing 90 x 10 t of iron world resources are estimated at 180 x 10 t of iron. Only a small fraction of world production is required for fertilizer use. 

Molybdenum. U.S. reserves and resources are about 3 and 13 x 10 t, respectively. World reserves and resources are about 6 and 23 x 10 t, respectively (108). The requirement for fertilizer is very small. 

World reserves of germanium have been estimated at 4000 metric tons, but it is impossible to discuss reserves without considering price. In many apphcations, the cost of germanium is but a small part of the overall cost of the product. Thus substantially higher germanium prices would have Htde impact on such uses but would expand germanium reserves significantly. 

World Reserves and Resources. A summary of demonstrated and inferred worldwide reserves of lithium is given in Table 2. The reserve base and the lithium equivalent represent resources in the ground. An overall lithium recoverabiUty of 65% for pegmatites and 33% for brines must be apphed to these values to estabUsh the amount of lithium that could eventually reach the marketplace (15). 

Table 4 gives typical analyses of some of the commercial manganese ores available ia the world market. Table 5 gives a breakdown of the world s total estimated manganese ore reserves that account for 98—99% of the known world reserves of economic significance. No manganese ores of commercial value are to be found ia the United States. 

Table 1. Grade of Ore for Economic Processing and Estimated World Reserves...

Table 1. World Reserves and Production of Soluble Potassium Salts, t x 10 K O...

Deposits. Selenium forms natural compounds with 16 other elements. It is a main constituent of 39 mineral species and a minor component of 37 others, chiefly sulfides. The minerals are finely disseminated and do not form a selenium ore. Because there are no deposits that can be worked for selenium recovery alone, there are no mine reserves. Nevertheless, the 1995 world reserves, chiefly in nonferrous metals sulfide deposits, are ca 70,000 metric tons and total resources are ca 130,000 t (24). The principal resources of the world are in the base metal sulfide deposits that are mined primarily for copper, zinc, nickel, and silver, and to a lesser extent, lead and mercury, where selenium recovery is secondary. 

Tungsten deposits occur in association with metamorphic rocks and granitic igneous rocks throughout the world (Table 2). Deposits in China constitute over half of the world reserves and over five times the reserves of the second largest source, Canada. 

World reserves of antimony (5) ate estimated to be from 4—5 million metric tons. Approximately 80% of the world s reserves are located in China, Bohvia, Russia, Thailand, the RepubHc of South Africa, and Mexico China has the world s largest reserves. The United States possesses only 2% of the world s reserves. Most of the antimony produced in the United States is from the complex antimony deposits found in Idaho, Nevada, Alaska, and... 

Beryllium, like its neighbours Li and B, is relatively unabundant in the earth s crust it occurs to the extent of about 2 ppm and is thus similar to Sn (2.1 ppm), Eu (2.1 ppm) and As (1.8 ppm). However, its occurrence as surface deposits of beryl in pegmatite rocks (which are the last portions of granite domes to crystallize) makes it readily accessible. Crystals as large as 1 m on edge and weighing up to 60 tonnes have been reported. World reserves in commercial deposits are about 4 million tonnes of contained Be and mined production in 1985-86 was USA... 

Coal is the least expensive and most sustainable fossil fuel energy source (world reserves of 1.2 to 1.8... 

Coal is the giant of fossil fuel resources. World reserves are many times those of petroleum, and the United States is one of the major resource holders. Coal can be used directly in combustion or converted to gas or liquid. Only combustion consumes significant amounts of coal today. 

C04-0111. The element titanium is commonly found as the ore ilmenite, F eTi03. Much of the world reserves of titanium is found in Canada. At a particular mine, a sample of earth was found to contain 15% ilmenite by mass. What mass of pure titanium metal can be isolated from 1.00 x 10 metric tons of earth, if the extraction process is 95% efficient ... 

Despite its relatively late discovery, phosphorus is the eleventh most abundant element in Earth s crustal rock. It has been estimated that world reserves of phosphate rock are sufficient to last for several hundred years. Virtually all phosphorus deposits contain apatite, whose general formula is Caj (P04)3 X, where X — OH, or Cl. Fluoroapatite is the least soluble, hence most abundant, of the three apatite minerals. Phosphorus Is found in aqueous systems as HPOq and H2 PO4 ions. In biological organisms, phosphorus is a component of nucleic acids and energy-shuttling molecules such as ATP. 

With the increasing costs of raw materials and the threat of depletion of world reserves of many resources, electrochemical processes should become more attractive to reuse and recycle wastes/materials. The recovery of metals in chemical solutions is very important from both the environmental and economical view points [232]. 

U.S. dependence upon imported oil could grow faster depending on oil availability. The petroleum reserves in the U.S. could be depleted more rapidly but U.S. reserves, which were once about as large as Saudi Arabia s, have been depleted to the point where some believe that we now have less than 3% of the world s remaining oil reserves. The U.S. uses oil at a rate that amounts to more than 25% of the world s production, but both U.S. and world reserves have been growing as improved recovery techniques are applied to older fields. 

Increasing concern for the need to conserve and to use effectively world reserves of raw materials and, at the same time, to reduce the quantities of waste materials which are likely to have an adverse effect on the environment has led to pressure for the increased use of renewable resources and so-called green chemistry . The principles of green chemistry have been enunciated by Hamley and Poliakoff as follows ... 

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