Coal deposits

X 10 J/kg(10.4 X 10 Btu/lb) in 1990. The shift in coal production toward western coal deposits also reflects the shift in coal utilization patterns (Table 7). Electric utiUties are increasing coal consumption on both absolute and percentage bases, whereas coke plants, other industrial operations, and residential and commercial coal users are decreasing use of this soHd fossil fuel. 

Coal, tar, and heavy oil fuel reserves are widely distributed throughout the world. In the Western hemisphere, Canada has large tar sand, bitumen (very heavy cmde oil), and coal deposits. The United States has very large reserves of coal and shale. Coal comprises ca 85% of the U.S. recoverable fossil energy reserves (6). Venezuela has an enormous bitumen deposit and Brazil has significant oil shale (qv) reserves. Coal is also found in Brazil, Colombia, Mexico, and Pern. Worldwide, the total resource base of these reserves is immense and may constitute >90% of the hydrocarbon resources in place (see... 

The importance of a coal deposit depends on the amount that is economically recoverable by conventional mining techniques. The world total recoverable reserves of lignitic coals were 3.28 x 10 metric tons at the end of 1990 (3), of which ca 47% was economically recoverable as of 1994 (Table 4). These estimates of reserves change as geological survey data improve and as the resources are developed. 

North America.. In the United States, lignite deposits are located in the northern Great Plains and in the Gulf states. Subbituminous coal is found along the Rocky Mountains. The western half of North Dakota has about 74% of the nation s resources, Montana 23%, Texas 2%, and Alabama and South Dakota about 0.5% each. The lignite resources to 914 m represent 28% of the total toimage of all coal deposits in the United States. The lower cost and low sulfur content have contributed to rapid growth in production. 

A. E. Duzy and co-workers, "Western Coal Deposits, Pertinent QuaHtative Evaluations Prior to Mining and Utilization," paper presented at Ninth... 

Between 1930 and 1950, the primary emphasis of ammonia process development was ia the area of synthesis gas generation (3) (see Fuels, SYNTHETIC, GASEOUS FUELs). Extensive coal deposits ia Europe provided the feedstock for the ammonia iadustry. The North American ammonia iadustry was based primarily on abundant suppHes of low cost natural gas (see Gas, natural). 

Seam correlations, measurements of rank and geologic history, interpretation of petroleum (qv) formation with coal deposits, prediction of coke properties, and detection of coal oxidation can be deterrnined from petrographic analysis. Constituents of seams can be observed over considerable distances, permitting the correlation of seam profiles in coal basins. Measurements of vitrinite reflectance within a seam permit mapping of variations in thermal and tectonic histories. Figure 2 indicates the relationship of vitrinite reflectance to maximum temperatures and effective heating time in the seam (11,15). 

Reactions of Goal Ash. Mineral matter impurities have an important effect on the utili2ation of a coal. One of the constituents of greatest concern is pyrite because of the potential for sulfur oxide generation on combustion. The highest concentrations of pyrite are associated with coal deposition under marine environments, as typified by the Illinois Basin, including parts of Illinois, Indiana, and Kentucky. Additionally, the mineral matter... 

Coal deposits from east of the Mississippi River generally have acidic mineral constituents, ie, they are richer in siUca and alumina and tend to produce higher melting ash mixtures. These materials do not soften until above 1000°C and have limited problems with deposition on the inside walls of the boiler (slagging) or on the superheater tubes inside the boiler (fouling). 

Both classes of hydrocarbon occur naturally, notably in oil and coal deposits. Aromatic compounds are also products of incomplete combustion of organic compounds, and are released into the environment both by human activities, and by certain natural events, for example, forest tires and volcanic activity. 

The production of coke from coal is an important activity in the ferrous metallurgical industries. While coal serves as the principal source for coke, a second source, namely, heavy petroleum fractions, is especially important for countries which have large petroleum resources and lack coal deposits. The properties of metallurgical coke are listed in Table 1.29. 

The most significant Tertiary coals are represented by the vast brown coal deposits in Victoria, particularly in the Latrobe Valley. These brown coals with 68-70% carbon, occur in very thick seams (up to 200 meters) under shallow cover (<30 meters). These coals differ from the Tertiary brown coals of North America in that they have a much lower ash yield and significant amounts of the ash-forming inorganic constituents are present as cations on the carboxylic acid groups which are a characteristic of low rank coals ... 

Coal is the most abundant fossil fuel on Earth and is expected to continue to be an important source of energy over the next several hundred years. Coal deposits are widely... 

There are two main reasons for the economic importance of Fischer-Tropsch production in South Africa (a) the existence there of extremely large coal deposits which can be mined at low cost, and (b) that nation s wish to become independent of external oil supplies. 

Wubo" means an abundance of untapped subterranean resource deposits, potential sources of electric power and farm products. It is estimated that China s coal deposits amount to 1600 billion tons, iron ore deposits 120 million tons, and petroleum several billion tons. China s hydroelectric power alone is estimated to total 35 billion kilowatts. 

Near term options include primarily the unconventional natural gas resources (Western tight gas sands, Eastern Devonian gas shales, geopressured aquifers, and methane from coal deposits). Mid-term options include coal gasification (peat... 

In 2002, 5,000 million tons of coal were produced globally. China is the largest coal producer in the world, while the United States is the second largest producer, with widespread coal deposits in the Appalachian Mountains, the western Rockies, and the state of Texas. 

The distribution of cool is very extensive it is found in almost every country, although to a very unequal extent. The United States may be considered as the most highly favored in this respect, if the area of tkoir coal deposits be taken into account, irrespective of the extent to which they are worked. It happens, however, that, from the abundance of wood, the home consumption of the article is limited, while the conveyance is costly, so that the benefits which result from valuable coal seams in other nations, remain to be developed in Amorica. According to the Statistical calculations of Mitchell, the annexed table represents the amount and varieties of the mineral coal treasures in the United States —... 

In the area of her coal deposits, Britain, rauks next to the United States, and greatly exceeds the latter in the extant end value of her workable mines. The total extent of coal in England is estimated at about six thousand and thirty-nine square miles, or one-eighth of the whole area in Scotland, one thousand seven hundred and twenty square miles, or one-eighteenth of the whole and in Wales, one thousand one hundred and sixty square miles, or about one-sixth of its entire extent. 

Bitumen describes a black or dark brown masticlike material that is thermoplastic in nature and softens upon heating. The sources of bitumen are petroleum or coal deposits. The natural product is commonly called gilsonite or pitch, a mineral formed by an old weathered petroleum flow at the surface of the earth that has left behind the larger molecules from the petroleum. A principal source in the past has been Lake Trinidad, a 445,000 m2 deposit on the island of Trinidad. Bitumen from petroleum or crude oil is called asphalt (qv). It is the material left behind after all the valuable compounds, eg, gasolines, have been distilled out of the cmde oil. The amount and quality of asphalt is dependent on the source of the crude oil used in the refining process. Some cmde oils have a higher content of asphaltic bitumen left after the distillation process. Bitumen from coal is coal-tar pitch. It remains after the valuable coal oils and tars have been distilled out of the coal tars produced by distractive distillation. Most industrial applications for bitumen products use asphalt or coal-tar pitch because the supply is more uniform and plentiful. 

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