The numerical value as established in ASTM D3173 or D7582 is used for converting the asdetermined data to a dry basis. • Dry, ashfree basis (daf): The basis for data calculated to a theoretical basis of no moisture or ash associated with the sample. Numerical values as established by ASTM D3173 and D3174, or D7582, are used for converting ...
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Typical comparison of readsorption curves between the ovendried coal sample and blending of the hot oven (150 C) dried coal sample (500 g) with 200 g of raw (airdried) coal sample.
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It is observed that a significant increase in the concentration of CO occurred at 110 °C for raw coal and 90 °C for soaked coal, thus the inflection point temperatures for two coal samples were set at 110 °C and 90 °C. The results indicate that although the soaked coal sample was dried by air, some changes occurred in coal structure.
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2 EXPERIMENTAL A Spanish subbituminous A coal named Encasur was used in the liquefaction experiments. It was first dried in air and then ground and sieved to a particle size of 100200 μm.
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SAMPLE PROBLEMS: 2 g of Dried Air Coal sample was taken in Silica Crucible, after heating it in a muffle furnace at 105110°C for 1 hour, the residue was weighted 2 g. The residue was heated in silica crucible covered with vented lid at temperature 950 ± 20°C for exactly 7 minutes. After cooling weight of residue was found to be 1 g.
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Experimental system Thermal analysis. The thermal analysis experiment used a STA449C synchronous thermal analyzer. The initial temperature of the experiment was 30 °C; the heating rate was 10 °C/min; the termination temperature was 800 °C; and the mass of coal samples at different immersion times and airdrying times was 25 ± 1 mg.
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Air drying or drying in a nitrogen atmosphere can be used for either method, depending on the coal rank. Drying in a nitrogen atmosphere is suitable for all hard coals, while drying in air is suitable only for hard coals not susceptible to oxidation. 1. Singlestage—The sample is crushed to a nominal topsize of mm. A subsample is dried ...
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The coal is first finely ground and air dried. Samples of the dried coal are then subjected to several operations, with the sample weights being recorded before and after each operation. Moisture content is determined as the weight loss when a sample is held at 105°C in an oxygenfree atmosphere for roughly 2 hours, added to the weight loss ...
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ADB AirDried Basis. In coal sample analysis, ADB neglects the presence of moistures other than inherent moisture while DB (drybasis) leaves out all moistures, including surface moisture, inherent moisture, and other moistures. ARB AsReceived Basis. In coal sample analysis, ARB puts all variables into consideration and uses the total ...
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Analysis sample of about 300 g of airdried coal, ground to p ass 21 2micron IS Sieve; and in addition special moisture sample of 1 kg of coal, crus hed to pass IS Sieve 125 mm, to be sent in ...
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Moisture determination: place g of airdry coal samples in a shallow wall crucible and put the crucible on the ceramic rotary table of the heating furnace for moisture and ash measurement (Analyzer II). ... The bottom of coal sample is a type of dim coal with the poorly developed fractures, only showing a little number of fractures ...
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Visualization of coal analysis bases (1) Airdried is calculated using the analysis moisture (AM) and not the residual moisture (RM). RM and AM are often similar in value, ... Sample preparation includes air drying, crushing, dividing, mixing, and sometimes cleaning of coal. Division and reduction of coal samples may occur at different ...
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1 Scope. This International Standard describes two methods for determination of the total moisture content of hard coals, a twostage method and a singlestage method. For either method there is a choice between drying in air and drying in a nitrogen atmosphere. Depending on the coal rank, there may be systematic differences between the results ...
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Airdried moisture: Moisture (water) in a sample after airdrying. Airdrying removes surface moisture prior to analysis. Because this term was also sometimes used for residual moisture, it was withdrawn by the American Society for Testing and Materials (ASTM method D12109; American Society for Testing and Materials, 2013, p. 355368).
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Experimental Procedure : About 1g of finely pulverized 212 micron (BSS) airdried coal sample is weighed in a silica crucible and then placed within an electric hot air oven. It is maintained at 110o C. The crucible with the coal sample is allowed to put in the oven for hours and it is taken out with the help of tongues, and then cooled in ...
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A certain number of coal samples is preairdried into airdried coal samples for laboratory use, which are dried to a constant weigh t at 102105 ℃, make the coal sample
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The surface moisture (also known as free moisture) of coal is the moisture attached to the particle surfaces and large capillary pores (of diameter greater than 10 −5 cm) in the mining, transport, storage, and washing of coal; it is represented by the symbol M f (%).
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To keep the energy consumption per unit mass of coal dried by hot air the same as that for microwave dried sample, 80 g of the sample with three different kinds of particle sizes was also placed in a drying chamber and the temperature of the drying chamber was kept at 105 °C with a power of kW. Moisture loss was measured by taking out and ...
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by heating an airdried coal sample at 105 ... (Btu/lb dry) OF THE INDIANA DANVILLE COAL Source: M. Mastalerz, A Drobniak, J. Rupp and N. Shaffer, "Assessment of the Quality of Indiana coal for Integrated Gasification Combined Cycle Performance (IGCC)', Indiana Geological Survey, Indiana University, June 2005
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That means drying the coal at ambient temperatures or at elevated temperatures not exceeding 40°C (SANS 589:2009, 2009). The apparently dry coal obtained is referred to as 'airdry'. The mass loss from wet coal to 'airdry' coal is referred to as free moisture content. The mass loss when a sample of airdry coal, after proper sample ...
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1g of air dried coal sample is taken by weighing in a balance of 212 micron (72 mesh BSS). A pellet is made with the coal and weighed. The calorimeter cover is taken and about 10 ml/min of distilled water is poured into it. The pellet in the crucible is brought in contact with the fuse wire by means of a thread. The cover is then tightened.
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Alteration measurements were made in air and in vacuum. A sample of fresh Goonyella coal (10mm, floated to % ash adb) was oxidised by boiling in 30% H 2 O 2 at 100°C for an hour. Figure 1 shows the fluorescence spectra of fresh and treated coal. There is a large decrease in fluorescence intensity.
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The specific experimental steps are as follows. Filling the Sample. Put 50 g samples to be tested into the sample tank, and cover a layer of asbestos with a thickness of 23 mm evenly above the coal sample, filter the air flow to prevent blocking the gas path, tighten the sample tank with screws at both ends, and seal both ends of the sample tank and the inlet and outlet joint with ...
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The airdried coal sample exhibits a considerably lower oxygen reactivity than the untreated coal sample. This is not unexpected in view of the fact that the airdried 184 FUEL, 1992, Vol 71, February Effect of drying methods on oxygen reactivity: S. Onal et al. Figure 1 Schematic outline of drying procedure n; 0 00o 32 n o a T a 01 a l' 24 a ...
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Moisture content in a coal sample is measured by placing 1 g of airdried coal sample of comminated 212micron size in a petri dish, as shown in Fig. 3a. Further, it is placed in an electric hot air oven and kept at 108 °C along with the lid for 1 h, as illustrated in Fig. 3b. Then, the sample is cooled to room temperature in a desiccator for ...
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according to formula added adjust Airdried base airdried coal sample Annex aperture correction value automatic Beckman thermometer benzoic acid bomb calorific value calculation calculation methods calibration calorimeter carbon coal water slurry combustion dish conduct connected constant pressure constant volume continuous correction value ...
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About 1 gm of powdered, air dried coal sample is heated in silica crucible at 100 to 105 °C for one hour. Percentage of moisture can be calculated from the loss in weight of the coal sample as
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After being soaked in water for 20 days and air dried for 10 days, the coal sample loosened and the chain reaction accelerated. These effects promote the oxidation and spontaneous combustion of coal. Coal samples immersed for 90 days and air dried for 4 days show decreased activation energy and increased tendency for spontaneous combustion.
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A sample of coal was found to have the following composition by weight C = 75%; H = %; O = %; N = % and ash = % Calculate (i) minimum amount of O2 and air necessary for complete combustion of 1 kg of coal; (ii) weight of air required if 40% excess air is supplied. ...
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