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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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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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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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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The normal preparation procedure requires that each airdried coal sample pass through a jaw crusher; one subsample (split) of the crushed material (2 to 4 mm, or 5 to 10 mesh) is then taken for the ultimate and proximate analyses, and another split is reduced to approximately 150 m m (100 mesh) by a vertical grinder for chemical analysis.
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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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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 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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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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the analysis sample of coal or coke. It is used for calculating other analytical results to a dry basis. When used in conjunction with the air drying loss as determined in accordance with Method D 2013 or Practice D 346, each analytical result can be calculated to an asreceived basis: This standard does not purport to address all of the
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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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A known weight of powdered and air dried coal sample is taken in a crucible and it is placed in preheated oven for 1 hour at 110 C. Then the coal is cooled in a dessicator and weighed out. If the initial weight of the coal is m gms and final weight is m1 gms. Then the loss in weight corresponds to moisture in coal.
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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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According to Figure 2, compared with raw coal samples, watersoaked and airdried coal samples corresponded to higher absolute generation volumes and generation rates of CO and C 2 H 4 in the lowtemperature oxidation process. As the temperature rose, the volumes of generated indicator gases climbed slowly first and soared later.
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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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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 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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When processing coal samples, peel off the oxide layer and sieve into 4080 mesh ( mm). To avoid the interference of the original moisture, place the samples in a drying oven to dry for two days. The coal sample was removed and soaked in a conical flask for 200 days and then airdried for 3 days.
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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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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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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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The coal is first finely ground and airdried. 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
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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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1. Moisture content About 1 gm of powdered airdried coal sample is taken in a crusible, and is heated at 100 − 10 5 ∘ C in an electric hotair oven for 1 hour. The loss in weight of the sample is found out and the % of moisture is calculated as % of moisture in coal = weight of airdried coal loss in weight of the coal × 100 2.
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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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For the preparation of different water content coal samples s, taking the 115mm coal sample as an example, each coal samples from all the four particle sizes was evenly mixed, soaked in water for 6 h, then dried naturally on the filter screen for at least 20 h, then the coal samples were weighed, and the water contents of the coal samples were calculated.
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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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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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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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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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In this method, g of airdried coal sample of size 212 µ was taken, pressed to a pellet, and introduced in the bomb. Then it was fired with oxygen, and the result of airdried GCV was recorded. The results of GCV for raw and treated coals were presented in Table 1. (C) Inherent moisture
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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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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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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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