The water content of coal is determined by the industrial analysis of coal. Water is the water of air drying coal samples (Mad). A certain number of coal samples is preairdried into airdried coal samples for laboratory use, which are dried to a constant weight at 102105℃, make the coal sample
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(5 marks) 6 (b) gm of air dried coal sample was taken in a crucible, after heating it in an electric oven at 110°C for 1 hr the residue was weighed gm. The residue was heated in Silica crucible covered with vented lid at a temperature 925±257°C for exactly 7 minutes. After cooling the weight of residue was found to contain gm.
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Air dried basis: The coal has naturally dried in the open air until it cannot dry or dissipate any more moisture. Use the coal in air dried basis to represent coal content. 3. Dry basis: An analysis expressed on the basis of a coal sample from which the total moisture has in theory been removed. Coal in dry basis includes all contents but moisture.
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gm of air dried coal sample was taken in a silica crucible, after heating it in an electric oven at 1050∘C − 1100∘C 1050 ∘ C − 1100 ∘ C for 1 hour, the residue was weighed gm. The residue was heated in silica crucible covered with vented lid at temperature 950 − 9700∘C 950 − 9700 ∘ C for exactly 7 minutes.
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After the stagnant water is discharged, the residual coal is airdried under the action of air leakage (Fig. 1), forming dried waterimmersed coal (DWIC) [1]. ... For type Ⅲ (the YHP coal sample), the adsorption capacity of the sample continued to increase with increasing relative pressure during the whole adsorption process, and the ...
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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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After soaking in water, the volume of the raw coal sample expanded, cracks and pores became more developed, and oxygen absorption was greater after water was removed by drying. ... . 19 pointed out that as the number of active functional groups and the oxidation heat release of the waterimmersed and airdried coal increase, ...
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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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Aad — The ash content of airdried coal sample, %. Method B (weighing coal sample) Sample treatment Ashing of coal sample. Accurately measure 1g~ of airdried coal sample with particle size less than (ash content is around ~). Put it in an ashpan, accurate to Shake it gently to spread it evenly.
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T 2 distribution and accumulated integral area of pores with different pore sizes for saturated coal after 8 h of drying. Note: sample number 11Rc indicates the test result of the first sample in the first experimental group under raw coal conditions. 11ad8 h is the test result of the first sample in the first experimental group after drying for 8 h in the air environment after saturation.
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Example 1: You have a set of airdried results where the asanalyzed Moisture is % (ad) and Ash is % (ad). For a contract you are required to report the Ash to a Moisture basis of % basis. 100 Moisture (required basis) . Ash result (ad) = Ash result (at required basis) 100 Moisture (ad) (100 ) . = % (ad) (100 )
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Method B (air drying method) Method summary Weigh a certain amount of coal sample for general analysis test; place them in blast drying oven at (105 ~ 110) °C; dry them in an air stream to a constant mass. The mass fraction of water is calculated from the mass loss of the coal sample. Instrumentation
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The physical and chemical properties of the airdried residual coal after soaking in the goaf will change, resulting in an increase in its spontaneous combustion tendency. This study aimed to look into the features and mechanism of soakeddried coal's spontaneous combustion. Five samples of coal were dried to various degrees, and the weight loss features during thermal processing were examined ...
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where M ad represents the airdrying base moisture, %; m and m 1 are the coal sample weight and its lost after the drying, g. The equilibrium moisture ( M e ) is defined as the moisture content when the pore water in the coal sample with ∼ mm pores reaches saturation at a temperature of 30°C and a relative humidity of 96% (using a ...
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At this time, the hightemperature oxidized coal sample in the goaf experienced water immersion and airdrying, and its surface pore structure changed greatly (As shown in Fig. 1). Therefore, the change in oxygen concentration caused by the strength of air leakage under the development of coal and rock mass fissures, and the ratio of coal ...
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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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Asdetermined (airdried) basis: Usually denoted as "adm" or "ADM." Even after airdrying, coal typically contains some moisture, which is referred to as residual moisture. Asreceived basis: Results are calculated to the moisture condition of the coal sample when it arrived at the testing facility. Usually written as "AR." Dry basis:
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coal and surface moisture present in the sample. (ii) Equilibrated Basis The sample is brought to standardized moisture and humidity levels and GCV of the resultant sample is reported. (iii) Air Dried Basis The given coal sample is air dried, as per procedure given by the Bureau of Indian Standards and the GCV is measured thereafter.
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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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Drying in a minimum freespace oven at 150 °C (302 °F) within a nitrogen atmosphere Drying in air at 100 to 105 °C (212 to 221 °F) and relative loss of mass determined Methods 1 and 2 are suitable with lowrank coals, but method 3 is only suitable for highrank coals as free air drying lowrank coals may promote oxidation.
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Asdetermined (airdried) basis: Usually denoted as "adm" or "ADM." Even after airdrying, coal typically contains some moisture, which is referred to as residual moisture. Asreceived basis: Data or results are calculated to the moisture condition of the coal sample when it arrived at the testing facility. Usually denoted as "ar" or "AR."
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Drying in air (two stage) airdrying followed by ovendr ying a. Stage I: special moisture sample of I kg of coal crushed (1 mm). weigh the sampl e and the
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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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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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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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Take (±) g (accurate to ) of airdry coal sample in a porcelain boat with a particle size of less than ; and cover the coal sample with a thin layer of tungsten xide. Place the porcelain boat on the quartz tray for sample delivery, start the sampledelivery program controller, and the coal sample shall be ...
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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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A sample of coal was analyzed as follows: Exactly was weighed into silica crucible. After heating for one hour at 110°C, the residue weighed The crucible next was covered with a vented lid and strongly heated for exactly seven minutes at 950 = 20° C. ... Solution: Weight of coal taken = gm Mass of moisture in coal = ...
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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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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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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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ADM is Air Dried Moisture (Moisture in the Analysis Sample) NM is Nominated Moisture AR is As Received Basis AD is As Determined (Air Dried) Basis ... Two stage total moisture determination is used when the coal sample is too small mass or too wet to divide or crush without the potential of losing significant amounts of moisture. TMar, % = [Rm ...
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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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Total moisture includes airdry loss moisture and inherent moisture. Airdry loss moisture, which is not linked to organic matter, is the loss of weight resulted by drying at room temperature. Inherent moisture content is determined by heating an airdried coal sample at 105°110°C (221230°F) under specified conditions until a constant ...
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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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