ASTM D_自然科学_专业资料。Designation: D – 07 Standard Practice for Preparing Coal Samples for Analysis1 This standard. ASTM. American Society for Testing and Materials. Btu/lb. British thermal units per pound cal/g (ISO ), or m/s (18 inches/s) (ASTM D). ASTM D/DM Standard Practice for Preparing Coal Samples for Analysis. standard by ASTM International, 09/01/ View all product details.
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A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. Unknown coals are to be considered under Group B. These lower weights may be used for particular coals if they have been shown, by using the procedures of Annex A1.
It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. The values given in parentheses are provided for information purposes only. Current edition approved June 1, Originally approved in Last previous edition approved in as D — Many terms used in this practice may be found in Terminologies D and E and in Practice E Summary of Practice 4.
The mass and top size of the gross or d0213 sample collected by using these guides and practices are usually too large for chemical or physical testing. Practice D provide instructions for reducing and dividing the gross or divided sample, by on-line or off-line processes, or both, to a top size and mass suitable to the performance of testing.
Any bias in the gross or divided sample before adherence to this practice will remain in the? Therefore, carefully select the standard to be used to collect the gross ast.
Most often, the sample is collected, reduced, and divided one or more times by use of a mechanical sampling system. The remaining sample may be further divided on-site to facilitate transporting it to the laboratory where further reduction and division likely occurs before analysis.
Procedures for air drying and air-dry loss determination are provided in Test Method D d201 However, some tests may require a sample of different mass or top size. This procedure may be used to provide a sample of any mass and size consist from the gross or divided sample to, and including, the analysis sample. Hard steel or chilled iron plate with tamper, sledge, asgm hand bar may be used for preliminary crushing of any large lumps in the sample before feeding into the crusher.
Crushers should be designed and operated in a manner to minimize the effect of induced air circulation and thus the potential for drying the coal. Typical mechanical sample dividers are shown in Fig. These illustrate various designs, but other acceptable designs are available.
Riffle slots should be at least three times the top size of coal being divided. A typical riffle is shown in Fig. It is preferable that feed chutes and enclosed riffles be used.
The minimum discharge opening of the feed chute shall be the same width as the riffle slot opening. The wheel provides space for a number of containers depending on its diameter and is turned slowly by a small motor and reduction gear.
The wheel should be rotated at a speed so that the particles fall gently from top to bottom of the container, mixing the sample thoroughly. The container should be about half full and never more than two thirds full to obtain good mixing of the sample.
Glass containers, sealed with rubber gaskets, may be used, but care must be taken to avoid breakage in transport.
ASTM D 2013 – 1986 Standard Method of Preparing Coal Sample for Analysis
Sample preparation should be checked at intervals by the methods described in Annex A1 or Annex A2. A separate moisture laboratory sample may be required, and portions may be required for grindability and other tests. Also, a reserve sample may be desired in case a check analysis or test is required.
Test Method D speci? At regular intervals, the cutter movement is reversed and a sample increment is collected on each trip through the coal stream.
Each cutter is designed to extract increments from the feed and to discharge these into the hollow shaft. One or more cutters may be used. Two slotted cones are locked together and rotated on a vertical shaft so that on each revolution the common slot operating intercepts the falling stream of coal and collects an increment. Sieve tests shall be made and reported in accordance with Test Method D D — 07 FIG.
Samples may require air drying to feed properly through the reduction and dividing equipment. Air dry in accordance with Test Method D Riffles properly used will reduce sample variability but cannot eliminate it. A typical enclosed riffle is shown in Fig. Pass the coal through the riffle from a feed scoop, feed bucket, or riffle pan having a lip or opening the full width of the riffle. Under no circumstances shovel the sample into the riffle or dribble into the riffle from a small-mouthed container.
Do not allow the coal to build up in or above the riffle slots. If it does not? Divide the ground subsample by riffling, using the small riffle see 6. Quickly pass the subsample through a ?
Reduce the particles retained on the screen, on a bucking board or mortar and pestle to pass the sieve, and add to what passed through the sieve and mix thoroughly. This is the analysis sample. Divide this subsample by riffling with the small riffle to not less than the quantity speci? Distribute this large number of increments equally throughout the entire discharge from the sample crusher because crushers can introduce appreciable segregation.
At each stage of division, take at least 60 increments. NOTE 1—It is recommended that, in the case of mechanical division in which an increment is not thoroughly mixed with other increments before division, a portion of each increment be collected by the subsequent stage increment collection process.
When the analytical parameters of interest are additive for example, proximate and ultimate analyses the preferred method is to test the individual samples and perform a ton-weighted mathematical average to determine the result for the lot or consignment. On the other hand, when the sought-after parameters are non-additive for example, ash fusibility and Hardgrove grindabilityanalysis of a composite sample is the only way to achieve a meaningful test result.
Another consideration is that since there are no provisions in this standard for dividing samples of top size larger than ? Taking these and other issues into account leads to the requirement that preparation of composites be performed with strict adherence to the procedures which are described below and are summarized in Table 2.
The details pertaining to the preparation of composite samples must be agreed to by all concerned parties. NOTE 2—As used in this standard, the term represent together with its related forms does not imply that samples satisfy a particular quantitative or statistical relationship to the coal which was sampled.
ASTM D – 00ae1 Standard Practice of Preparing Coal Samples for Analysis
The term is used within Practice D in the sense of its broad dictionary de? NOTE 3—As used in this standard, parameters which are additive are those having values that are not affected by interactions between the physical and chemical properties of the combined d2031 samples.
Non-additive parameters are those for which such interactions may occur or those for which de? Determine whether sample f2013 have been decreased, and by what percentage, prior to arrival of samples at the laboratory. Account for that information when making the composite. The samples may be reduced in nominal c2013 size for example, to pass a 2. Adhere to the minimum weights required in Table 1. It is advisable to mix the composite sample thoroughly, but without altering the moisture content, before reducing or dividing to smaller quantities.
Designate the results R1, R2, R Add the individual lot or sub-lot masses to? Mn to be combined to make the composite sample. Calculate the percentage of the total sub-lot or lot which each sample represents. Select an approximate desired mass for the composite sample. Multiply the desired composite mass d20013 the percentage of the total which each sample represents to? Do not produce riffle portions which are smaller in mass than stated in Table 1 of atsm standard. Select and combine the riffle portions which yield a close approximation of the desired mass.
Repeat for all samples, then combine the riffled portions of the original samples to form the composite. NOTE 4—It is highly unlikely that the exact number of grams needed for each sample can be obtained using a riffle while adhering to the requirements of Table 1.
Do not add or delete particles without using d20013 riffle in order to obtain the exact desired mass. The user must exercise judgment to assess when the riffled mass is sufficiently close to the desired mass so as to not materially affect the results of the test s for which the composite sample is being prepared.
Mix by mechanical means before extracting portions for analysis. Compute that value as shown below: Indicate on the laboratory report that data were obtained e2013 testing a close-approximation composite, and that the results may therefore not fully re?
Precision and Bias Since this practice does not produce a numerical result, determination of bias asm not applicable. The data obtained from tests using consistent sample preparation and analysis method are used to estimate the random errors in the various stages of sample division and analysis.
If, however, it is desired zstm crush directly to No.
ASTM D / DM – 18 Standard Practice for Preparing Coal Samples for Analysis
Divide each subsample to no less than the minimum weights as outlined in Table 1. The purpose of these tests is not to? Calculate the variances of these combinations: VP, the variance of the difference between duplicate analyses; VQ, the variance of the difference sstm the averages of duplicate analyses; and VR, the variance of the difference between the average of each four analyses, as follows: Data taken at intermediate steps are not consistent within limits of these rounding errors.
Thus, the difference 0. Coals used in these variance tests should be of similar ash content. Any gross change in the division and analysis methods or in the ash characteristics of the test coal will nullify the test results.