Beneficiation of noncoking coal (with high ash content of over 40%), particularly from large open cast mines extracting highly interbanded seams, is a technological necessity to ensure supply of consistent size and quality to distant cement plants. ... During the hard coal beneficiation process, coal tailing slurries and coarse, small, or fine ...
article{osti_, title = {Making liquid fuels from coal by solvent extraction process}, author = {Gorin, E and Phinney, J A and Reichl, E H}, abstractNote = {Solvent extraction processes for coal are improved if the hydrocyclone underflow, consisting of undissolved coal residue in a solvent, is maintained as a pumpable slurry containing at least 35% by volume of liquid.
The aim of this study is to extract alumina from ARCG by the hydrochemical process and determine the behaviour of Al 2O 3 during the extraction process. Meanwhile, the phase transformation of ARCG in hydrochemical process is also researched. 2. Experimental Raw materials The ARCG was derived from a coal mine of Shanxi Province, China.
The resultant coal extract solution is then hydrocracked to premium liquid products and a fraction suitable for recycling as process solvent. For the process to be economically attractive, it is important to achieve a high rate of filtration.
Laudal and colleagues have demonstrated they can generate a product with 60 to 90% (600,000 to 900,000 ppm) rare earths from lignite. They are now scaling up their solvent extraction process to a ...
Approximately 90% of nonfuel mineral resources and 60% of coal is extracted in the United States using surface mining. Processing. ... This process can be very dangerous for miners due to issues such as fires, explosions, and roof falls. According to the United States Department of Labor, in the early years of coal mining () there was ...
Coal mining Coal preparation: As explained above, during the formation of coal and subsequent geologic activities, a coal seam may acquire mineral matter, veins of clay, bands of rock, and igneous intrusions. In addition, during the process of mining, a portion of the roof and floor material may be taken along with the coal seam in order to create adequate working height for the equipment ...
Coal mining Extraction, Processing, Pollution: In geologic terms, coal is a sedimentary rock containing a mixture of constituents, mostly of vegetal origin. Vegetal matter is composed mainly of carbon, hydrogen, oxygen, nitrogen, sulfur, and some inorganic mineral elements. When this material decays under water, in the absence of oxygen, the carbon content increases.
Coal Mining Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity. Surface Mining If coal is less than 61 meters (200 feet) underground, it can be extracted through surface mining.
This Department of Energy National Energy Technology Laboratory sponsored project developed carbon products, using mildly hydrogenated solvents to extract the organic portion of coal to create synthetic pitches, cokes, carbon and carbon fibers.
For a discussion of the coalextraction process, see the article coal mining. For a more complete treatment of the processes involved in coal combustion, see the article coal utilization. History of the use of coal In ancient times. The discovery of the use of fire helped to distinguish humans from other animals.
2. A process for obtaining liquids from coal by heating in the absence of added hydrogen at a supercritical temperature between about 325° C. and about 425° C. a mixture of particulate coal of from about 4 to about 30 mesh and from about 50% to about 75% by weight of tetralin and from about 50% to about 25% by weight of xylene whereby said ...
Hydrocarbons from coal. James G. Speight PhD, DSc, PhD, in Handbook of Industrial Hydrocarbon Processes (Second Edition), 2020 Solvent extraction processes. Solvent extraction processes are those processes in which coal is mixed with a solvent (donor solvent) that is capable of providing atomic or molecular hydrogen to the system at temperatures up to 500°C (930°F) and pressures up to ...
A new process by Penn State chemists improves how we extract ... including industrial waste from burning coal and mining other metals as well as electronic waste from cell phones and many other materials. ... The researchers do not think their method will necessarily supplant the current liquidliquid extraction process that is commonly used ...
A schematic diagram incorporating the use of the alkaliacid leaching process to extract REEs from coal and coal refuse is shown in Figure 1. A negative aspect of the alkali leaching step is the considerable amount of contaminants dissolved into solution along with the REEs, which complicates the downstream purification process.
The dynamic factors generated by the redistribution of the initial rock stress by coal mining or methane extraction, static factors such as coal ranks, moisture contents, temperatures, and minerals of methane adsorption in coal also have attracted extensive attention. ... Based on the methane adsorption as an exothermic process, Tang et al ...
There are two main methods for extracting energy fuels from the Earth: mining and drilling. Mining is used to extract solid fuels, such as coal and uranium. Drilling is used to extract gaseous or liquid fuels, such as natural gas and crude oil. Subsurface mining describes the process of extracting resources from deep underground, using tunnels ...
Coal is either extracted from deep inside the earth or removed from its surface. The former is known as underground mining, the latter as strip mining or mountaintop removal. Either process contributes a high level of damage to the environment: #12 Noise pollution. One of the most obvious (albeit perhaps least harmful) environmental effects of ...
Coal mining (also called colliery) is the process of extracting coal from the ground's surface or from deep underground. Coal miners literally raze entire mountain ranges to feed our insurmountable desire for cheap energy. There's something brutally simple about coal mining.
About % coal gasification tar residue was extracted. The extract and residue were analyzed by GC/MS, FTIR and DSCTGA, respectively. Results revealed that coal gasification tar residue contained polycyclic aromatic compounds, which could be extracted easily by ethyl acetate. Boiling points of the extractable polycyclic aromatic compounds ...
Abstract. Nearly 40% of the worldwide electricity generated comes from coal; therefore, coal will remain a crucial contributor to the global security of energy supply in the following decades. In the extraction of precious coal products, 1 ton of hard coal produces tons of extractive waste materials, including coal washery rejects, tailings ...
Coalbed methane extraction (CBM extraction) is a method for extracting methane from a coal deposit. Coal bed methane (CBM) is one of the factors restricting safe production of coal in underground coal mines. It is also a form of highquality energy that can be used in many fields such as power generation, heating, and chemical industries.
[Show full abstract] separation of phenol, ocresol, and pcresol from the coal tar by solvent extraction process. The aim of the present work was to study the effect of two kinds of aqueous were ...
Resource Demands of Coal Production. In Environmental Impacts of Coal Mining Utilization, 1987. A Waterconscious Future. Having estimated the quantity and location of future coal production and processing, and the methods by which this coal will be extracted, transported and processed, Alcamo (1984) computed the industry's water requirements. He assumed a "waterconscious" future in ...
For high addedvalue utilization of alumina rich coal gangue (ARCG), a mild hydrochemical process was investigated to extract alumina. The influences of NaOH concentration, mass ratio of alkali to gangue, reaction temperature and reaction time were systematically studied. An alumina extraction rate of % was achieved at the condition of ...
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