Petrography, chemical composition, and stratigraphic setting of the coals of North-Central Missouri
"Under a grant from the National Air Pollution Control Administration, the Missouri Geological Survey undertook a core drilling program to learn more about the coals in north-central Missouri. The stratigraphic setting and chemical and petrographic characteristics of 43 complete samples of coal recovered from 13 diamond drill holes in the exploration program in north-central Missouri are major contributions of this study. These samples represent twelve different coal beds of the Atokan and Desmoinesian Series of the Pennsylvanian System of Missouri and range in thickness from 9.6 to 44.4 inches. They have an average thickness of 20.4 inches and a combined thickness of 71.8 feet. Detailec lithologic logs of the drill cores are an additional contribution of this investigation. In the seven county area of this report, there are an estimated 15.4 billion tons of coal resources. Of this total about 4.3 billion tons are classified as unmined coal reserves. Proximate and ultimate analyses, BTU and sulfur content including forms of sulfur are given for each of the coals sampled. The BTU content of the coals has an arithmetic mean of 10,447 as received. The arithmetic mean of the sulfur content of the coals is 4.69 percent as received of which 3.26 percent is pyritic, 1.39 percent is organic, and 0.04 percent is sulfate. The weighted average sulfur content based on thickness of the coal is 4.94 percent as received of which 3.37 percent is pyritic, 1.53 per cent is organic, and 0.04 percent is sulfate. The coals studied may be classified as high volatile bituminous. They have an arithmetic mean of 35.9 percent volatile matter and 13.8 percent moisture as received. The arithmetic mean of the fixed carbon content is 36.1 percent. Ash content is quite variable and ranges from 3.6 to 25.9 percent with an arithmetic mean of 11.9 percent. The maceral groups of vitrinite, inertinite, and exinite as well as mineral matter were identified and counted under reflected light from polished particulate sections of each of the 43 coal samples. This is the first time that such work has been done in Missouri. Vitrinite is the major maceral group present in the coals with an arithmetic mean of 80.1 percent. The vitrinite content of the coals increases irregularly towards the west in the study area. Inertinite has an arithmetic mean of 4.9 percent and exinite has an arithmetic mean of 2.5 per cent. Mineral matter is the second highest overall of the microscopic components studied, with an arithmetic mean of 12.5 percent. Practical uses of coal petrography in exploration and exploitation of coal mine lands are suggested. Other practical applications such as coal correlation, cost estimates in mining, and coal preparation are briefly described. A quantitative analysis was made of 74 elements with a mass spectrometer from seven selected coals. This was done by the U.S. Bureau of Mines at the request of the Missouri Geological Survey for this study. Most elements occur in the total coal sample in less concentration than the average amount of the same element found in crustal rocks of the earth. Sulfur, boron, silver, selenium, molybdenum, iodine, germanium, arsenic, and antimony are enriched in the total coal relative to the abundance of these nine elements in crustal rocks. The enrichment ratio ranges from 2 (antimony and arsenic) to 65 (sulfur)"--Abstract, pages ii-iii.
Missouri University of Science and Technology
Networked Digital Library of Theses and Dissertations