GB 475(1).docx

Commercial coal sample taken by manual methods GB 475-2008 Instead of GB 475-1996 1. **Range** This standard specifies the commercial coal sampling method of manual terms and definitions, the general principle of sampling and sampling precision, sampling scheme establishment, sampling method, m...

Commercial coal sample taken by manual methods GB 475-2008 Instead of GB 475-1996 1. **Range** This standard specifies the commercial coal sampling method of manual terms and definitions, the general principle of sampling and sampling precision, sampling scheme establishment, sampling method, manual sampling tools, packaging and labeling of coal sample and sampling report. This standard is applicable to **lignite, bituminous coal and anthracite**. 2. **Normative References** The clauses in the following documents become the terms of this standard by reference to this standard. For dated references, all subsequent amendments (excluding corrigenda) or revisions do not apply to this standard, however, parties to agreements based on this standard are encouraged to investigate the possibility of using the most recent versions of these documents. For undated references, the latest edition applies to this standard. 3. **Terms and Definitions** The following terms and definitions apply to this standard. 1. **Coal sample** A representative part of the coal taken in order to determine certain characteristics. 2. **Sample of commercial coal** Coal samples representing the average properties of commercial coal. 3. **Special test sample** In order to meet the requirements of a particular test, the preparation of coal samples. 4. **Common coal sample** Coal samples taken to carry out a number of tests. 5. **Total moisture sample** Coal samples for the determination of total moisture content. 6. **General coal sample** Specially taken for the preparation of coal samples for general analysis test. 7. **General analysis test samples** [Crushed to a particle size of less than 0.2mm and to air dry state, for most of the physical and chemical properties of coal samples.] 8. **Particle size analysis** Specially taken coal samples for particle size analysis. 9. **Increment** Sampling device to operate once or interception of a cross-section of the coal flow, increment taken. 10. **Decimation increment** Consists of several sub-uniformly distributed throughout the primary sampling unit samples consisting of coal samples. (Decimation increment comprises several sub-uniformly distributed samples throughout the primary sampling unit, which consist of coal samples.) 11. **Gross sample** All the increments taken from a sample merged into the coal sample. 12. **Primary Increment** The sample taken in the first stage of sampling, before any breakage and division. 13. **Reduction (dividing) sample** In order to reduce the sample mass, sample is divided. 14. **Sampling** Process of taking a representative part of coal from a large coal. 15. **Continuous sampling** From **each sample unit** to take a sample, Increment points spaced evenly. 16. **Intermittent sampling** Sampling only from a **few sampling units.** 17. **Batch lot** An independent quantity of coal is required to determine the overall properties. 18. **Sampling unit** 19. **Nominal top size** With the cumulative oversize mass fraction is closest to **(but not more than 5%)** the corresponding sieve size. 20. **Precision** The degree of compliance between the independent tests results obtained under the specified conditions. Formula of variance V= Note 1: It is often expressed as a precision index, such as twice the standard deviation. Note 2: The precision of coal sampling is the difference between the result of single sampling measurement and the average value of the results of the measurement of the same coal (the same source, the same nature) for countless sampling (at 95% probability)..?????? 21. **Systematic Sampling** The increments are taken at the same time, space, or mass interval**, but the first subsample is taken at random** within the first interval and the remaining increments are taken at the selected intervals. 22. **Random sampling** Take the sample, the sampling location or time are not applying, any human will have the opportunity to make any part of the coal collected. 23. **Time-based sampling** The increment is taken from the coal flow and the position of each increment is determined by a time interval proportional to the coal flow at the time of sampling. 24. **Mass-based sampling** The increments are taken from a coal flow or still coal, the position of each increment being determined by a mass interval, and the increment mass fixed. 25. **Stratified random sampling** A random sample is taken **at the mass or time interval** of the mass-based sampling and the time-based sampling division. 26. **Error** The difference between the **observed value and the acceptable parameter**. Note: in all the sampling, sample preparation and testing methods, the error always exists, and at the same time the test results obtained by this method can also deviate from the true value of the parameter. Since the \"true value\" cannot be known exactly, it is often measured using a relatively accurate method, which is an acceptable 27. **Variance** The **measure of dispersion**. Is the sum of the squares of the difference between the observed value and their mean value divided by the degrees of freedom (the number of observations minus 1)  28. **Standard deviation** The square root of the variance. 29. **The coefficient of variation** The standard deviation of the arithmetic mean of the absolute value of the percentage, also known as the relative standard deviation.??? 30. **Random error** 31. **Bias** System error. **It leads to a series of results that are always higher or lower t**han the values obtained by a reference method. 32. **Substantive bias/ relevant bias** Permitted bias with the actual importance or consent of the parties to the contract. 4. **The general principles and sampling precision sampling** 33. **General principles of the Sampling:** The purpose of coal sampling and sample preparation is to obtain a test coal sample whose test results represent the whole batch of sampled coal. The basic process of sampling and sample preparation is to **first collect a considerable amount of coal from many points distributed in the whole batch of coal**, that is, the primary sample, and then merge the primary samples directly or after the sub-divided into a total sample, The total sample is then subjected to a series of sample preparation procedures to produce the required number and type of test coal samples. The basic requirement of sampling is that all the particles of the sampled coal may enter the sampling equipment, and each particle has equal probability to be collected in the sample. In order to ensure that the precision of the test results obtained by the sample meet the requirements, Sampling should consider the following factors: a. b. c. d. 34. **Sampling precision** In all sampling, sample preparation and testing methods, the error is always present, while using this method to get any of the specified parameters of the test results will deviate from the true value of the parameter. Since the true value cannot be known exactly, the absolute bias of a single result to \"true value\" is impossible to measure, and only the precision of the test result can be estimated. The degree of coincidence between the results of a series of measurements on the same coal is the precision, and the deviation of the mean of the series of measurements from an acceptable reference value is biased. The sampling precision is related to the variability of sampled coal (primary sample variance, sampling unit variance), sample preparation and testing error, sampling unit number, subsample number and sample size. In the case of a certain amount of sample, the following formula can be used to estimate. The precision (P) of a single observation is given by equation (1) if a large number of replicate samples are taken from the same sampling unit and separately prepared and analyzed:........................................................................ (1) Where: S - Estimated total standard deviation of sample; V~SPT~ - Total variance of repeated samples. For a total sample, V~SPT~ can be given by equation (2):............................................................... (2) Where: V~I~ - primary Increment variance; V~PT~ - sample preparation and testing variance; n - The number of Increment of the total sample. The VSPT result when a batch of coal is divided into a plurality of sampling units and a total sample (i.e., continuous sampling) is taken from each sampling unit is given by the formula (3): \...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (3) Where: n - The number of increments in a single sampling unit; m - The number of coal sampling unit. Since a total sample corresponds to one member of a set of replicates, for successive samples, equations (4) and (5) are obtained by combining equations (1) and (3): \...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (4) \...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (5) Where: *P~L~* - The average number of coal-precision measurement values ​​at the 95% confidence level m sampling units; *P~SL~* - A sampling unit at 95% confidence level for the precision of sampling. When a batch of coal is divided into a plurality of sampling units, there may be a difference between the average values of the sampling units. When all the sampling units are sampled and tested, this difference does not lead to additional variance. However, if only some of the elements are sampled and tested (i.e., discontinuous sampling), then a sampling unit variance correction term should be added to equation (3), where VSPT and PL calculations are performed according to equations (6) and (7) : \...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (6) \...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (7) Where: *m* - The number of sampling units sampled in the batch; *u* - Number of sampling units in batches of coal; *Vm* - Sampling unit variance. 5. **Basic sampling scheme** 35. **Sampling Scheme Selection** **Sampling principle in accordance with the provisions of this standard basic sampling program. Special sampling plans shall be devised in the following cases, and the special sampling plan shall be implemented with the consent of the relevant parties:** **A) The sampling precision is expressed by the coal quality parameters other than ash;** **B) The required ash precision value is less than the values listed in Table 1;** **C) When a sampling plan has been agreed upon by the interested party.** **     Both the basic sampling plan and the special sampling plan shall be carried out according to the sampling precision verification and the bias test according to the provisions of Appendix C, and the requirements shall be confirmed.** 36. **Basic sampling program** 37. The total precision (ash, Ad) of sampling, preparation and testing of coal and other coal washing (including coal) is specified in Table 1.????? Table 1 Sampling precision (Ash, Ad) +-----------------+-----------------+-----------------+-----------------+ | Raw Coal, | Clean Coal | Other coal | | | screening | | washing | | | | | | | | | | (Including | | | | | coal) | | +-----------------+-----------------+-----------------+-----------------+ | ≤20% | \> 20% | | | +-----------------+-----------------+-----------------+-----------------+ | But not less | ±2% | ±1% | ±1.5% | | than±1% | | | | | | (Absolute | (Absolute | (Absolute | | (Absolute | value) | value) | value) | | value) | | | | +-----------------+-----------------+-----------------+-----------------+ 38. 39. Commercial coal varieties with 1000 t as a basic sampling unit. 40. when the amount of coal is less than 1000t or greater than 1000t, according to the actual situation, the following coal quantity is a sampling unit: a. A train load of coal; b. A boat load of coal; c. A car or a cabin load of coal; d. Period of time sent or received coal. 41. To check a single batch of coal quality, coal deal with the same sampling unit for sampling, sample preparation and testing. 42. **The number of increments per sampling unit** 43. The basic sampling unit subsamples of raw coal, screening coal, clean coal and other coal washing (including coal) are listed below: Number of increments are listed in Table 2. **Table 2: value of "n" when sampling unit is greater than or equal to 1000t** ------------------------------------- ----------- ------------------- ------- ----- ----------- ------ Variety Ash Range Sampling Location Coal flow train car Coal pile ship Raw coal, screening coal \> 20% 60 60 60 60 60 ≤20% 30 60 60 60 60 Clean Coal \- 15 20 20 20 20 Other coal washing (including coal) \- 20 20 20 20 20 ------------------------------------- ----------- ------------------- ------- ----- ----------- ------ 44. Number of increments when sampling unit is less than 1000t **When the sampling unit coal quantity is less than 1000t, the increment will decrease proportionally according to the number of increments according to Table 2,** **But at least not less than the stipulated number in Table 3.** Table 3 **sampling unit of coal is less than 1000t**, the minimum number of increments ------------------------------------- ----------- ------------------- ------- ----- ----------- ------ Variety Ash Range Sampling Location Coal flow train car Coal pile ship Raw coal, screening coal \> 20% 18 18 18 30 30 ≤20% 10 18 18 30 30 Clean Coal \- 10 10 10 10 10 Other coal washing (including coal) \- 10 10 10 10 10 ------------------------------------- ----------- ------------------- ------- ----- ----------- ------ 45. The number of increments when the coal sampling unit is greater than 1000t **Sampling unit of coal amount of more than 1000t,** the number of increments according to formula (8) Calculation......................................................... (8) Where: *N*- Number of Increment should be taken; *n* - Increment numbers in Table 2; *M*- Mass of coal to be sampled, tons (t); 1000\-- Basic sampling unit amount of coal in tons (t). 46. **Determination of number of coal sampling units:** A batch of coal can be used as a sampling unit, and can be divided into m sampling units according to the formula (9):.............................................................................. (9) Where: *M*- mass of coal to be sampled, tons (t). **When a lot of coal is divided into a number of sampling units, the precision of sampling is better than that of sampling unit.** 47. 48. The minimum mass of total sample: Table 4 and Table 5 show the minimum mass of the total sample or the total sample of the coal samples for the general coal sample (common sample), the total moisture coal sample and the particle size analysis coal sample, respectively. The minimum mass of the general coal sample given in Table 4 can be reduced to 0.01, which is equivalent to 0.2% of the ash variance due to particle characteristics. Note: In order to guarantee the precision of sampling, if the increment mass calculated by Eq. (10) and the increment number given in Table 2 and Table 3 are less than the specified values in Table 4 and Table 5, Sub-samples or sub-samples shall be added (see 5.2.4.2.1) until the total mass meets the requirements. Otherwise, the sampling precision is likely to decrease. Table 4: The total sample of the general coal sample, the total moisture sample / shrink total sample after the minimum mass +-----------------------+-----------------------+-----------------------+ | Nominal maximum | General coal and | Total moisture coal / | | particle size / | coal-like co /kg | | | | | kg | | mm | | | +-----------------------+-----------------------+-----------------------+ | 150 | 2600 | 500 | | | | | | 100 | 1025 | 190 | | | | | | 80 | 565 | 105 | | | | | | 50 | 170^a^ | 35 | | | | | | 25 | 40 | 8 | | | | | | 13 | 15 | 3 | | | | | | 6 | 3.75 | 1.25 | | | | | | 3 | 0.7 | 0.65 | | | | | | 1.0 | 0.10 | \- | +-----------------------+-----------------------+-----------------------+ | a Nominal maximum | | | | particle size of 50mm | | | | of coal, the total | | | | sample mass general | | | | analysis and the | | | | common minimum sample | | | | of 60kg. | | | +-----------------------+-----------------------+-----------------------+ Table 5: The total sample size analysis of minimum mass +-----------------------+-----------------------+-----------------------+ | Nominal maximum | The precision of 1% | Precision 2% of the | | particle size / | by mass / | mass / | | | | | | mm | kg | kg | +-----------------------+-----------------------+-----------------------+ | 150 | 6750 | 1700 | | | | | | 100 | 2215 | 570 | | | | | | 80 | 1070 | 275 | | | | | | 50 | 280 | 70 | | | | | | 25 | 36 | 9 | | | | | | 13 | 5 | 1.25 | | | | | | 6 | 0.65 | 0.25 | | | | | | 3 | 0.25 | 0.25 | +-----------------------+-----------------------+-----------------------+ | Note: The table is | | | | precision measurement | | | | precision sieve | | | | product yields, | | | | namely particle size | | | | greater than the | | | | nominal yield maximum | | | | particle size of coal | | | | precision, precision | | | | components for other | | | | size will generally | | | | be better. | | | +-----------------------+-----------------------+-----------------------+ 49. Sample quality 50. The minimum Increment mass: The minimum Increment mass is calculate by formula (10), but at least 0.5kg. \...\...\...\...\...\...\... (10) Where: ma\-- minimum Increment mass, in kilograms (kg); d\-- Nominal top size of the coal sampled in millimeters (mm). Table 6 gives the size of the sample or part of primary division after the minimum sample mass. Table 6: Minimum mass of primary increment according to top nominal size ----------------------- --------------------- Nominal top size (mm) Increment mass (kg) 100 6.0 50 3.0 25 1.5 13 0.8 ≤6 0.5 ----------------------- --------------------- 51. Increment average mass: When the total mass of the sample taken as specified in 5.2.3 and the minimum sample weight specified in 5.2.4.2.1 does not reach the minimum mass specified in Tables 4 and 5, The mass of the subsamples shall be increased to the average mass of the subsamples calculated according to Equation (11). \...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (11) **Where:** **- The average mass of the increment, in kilograms (kg)** **- Minimum total sample mass, in kilograms (kg);** ***n* - The number of increments.** 52. **Design special sampling scheme** 53. The basic procedure to set up the sampling plan is as follows: a. determine the **coal source**, batch; b. determining the **parameters** to be determined and the type of sample required; c. determining the **nominal top size** of the coal, the minimum mass of the total sample and increments; d. determining or assuming the required **precision**; e. Determine or assume coal **variability** (i.e., primary increment variance and sampling unit variance) and sample preparation variance; f. determining the number of **sampling units** and the number of increments of the sampling unit; g. Determine the **sampling method** used: **continuous sampling or intermittent sampling;** h. determine the **sampling mode** and sampling base: **system sampling, random sampling or stratified random sampling; time-based sampling or mass-based sampling**, and determine the sampling interval (min or t); i. determine the **location** of sampling; j. Determine the method of **combining the increments** and the sampling method. 54. **Design of sampling procedures:** 55. Outline The design of the sampling plan is based on the actual situation for the sampling staff to develop the first step in the operating instructions. The operating instructions are the operating rules for implementing the sampling, The elements included in all sampling plans and possible problems should be covered, Instructions should be simple, easy to understand, feasible, there can be only one interpretation and is fully understood and implemented by the sampler. According to the purpose of sampling - Technical evaluation, Process control, Quality control or commercial purposes determine the type of sample: General coal samples, water samples, particle size analysis of coal samples or other special samples. Determination of quality parameters according to the sampling purpose and the type of sample: Ash, moisture, particle size, or other physical and chemical properties. Sampling procedures should be designed to ensure that the measured parameters are not biased by sampling, sample preparation and sample storage prior to testing. In some cases, it is necessary to define the mass of the primary increment, the post-fractionation sample, and the test sample. 56. **Determining the precision of sampling** Sampling precision is determined according to the sampling purpose, sample type and the requirements of the parties to the contract. The sampling precision is usually expressed by the ash, and also can be expressed by other coal quality parameters. When it is used for precision, the ash content of dry base is 1/10. After the determination of precision, should be used in the routine sampling of double sampling method or multiple sampling method (see Appendix C) to confirm whether the accuracy of the requirements. 57. **Determining the variability of coal** 58. Determine the primary Increment variance The primary sample variance can be determined by one of the following methods: a\) Direct sampling of the sampled coal: at least 50 subsamples of the same coal or coal in the same coal source, each sub-sample prepared and tested, preferably dry-based ash. Then we use formula (12) to calculate the primary sample variance: Where: *VI* - Primary Increment variance; *n* -- Number of increment; *Xi* - Analysis of the parameters measured value; *V~PT~*- Sample preparation and testing variance. b\) The determination of the increment variance based on similar coal sampling in a similar sampling scheme; c\) In the absence of sample variance of data, for ash, initially can assume that V~I~ = 20, and check in after sampling. 59. **Sampling unit variance determination:** The effect of sampling unit variance is the same as that of the primary increment, but the influence degree is small. The sampling unit variance can be determined using one of the following methods: a\) Direct determination of sampled coal: At least 20 sampling units from the same batch of coal or several batches of coal in the same coal source, each take 1 samples, Sample and testing the samples separately, Determination of parameters preferably dry ash. Sampling unit variance is then calculated by the formula (13). \...\...\...\...\...\...\...\...\...\...\... (13) Where: Vm - sampling unit variance; m - The number of sample units; Xm - Total sample analysis parameter values. b\) Determination of the sampling unit variance based on a similar sampling scheme for coal; c\) In the absence of data sampling unit variance case, for the ash content, initially assumed= 5, and after the samples are checked. 60. Sample preparation and laboratory variance determination One of the following methods to determine the sample preparation and testing variance: a\) Direct determination is carried out by one of the following two methods: **Method one**: Method one: at least 20 samples are taken from the same batch of coal or the same kind of coal, Two samples were drawn from each sample (or taken at the first shrinking stage) Respectively, made of coal samples and analysis by routine analysis of laboratory quality parameters (preferably ash) And then according to equation (14) to calculate sample and laboratory variance: Where: *VPT* - Sample preparation and testing variance; *di* - The difference between the measured value of each sample; *np* - Number of samples pairs. **Method 2:** Make at least 20 samples of one or more of them, and make them into analysis samples and test the quality parameters of each sample (preferably ash). And then use the formula (15) to calculate sample and test variance: \...\...\...\...\...\...\...\...\...\...\...\... (15) Where: *VPT* - Sample preparation and testing variance; *j* - The number of samples; *Xj* - Sample analysis parameter values. b\) Determination of sample and assay variance based on similar procedures for the determination of coal in similar samples. c\) In the absence of sample preparation and laboratory variance data, for ash, VPT = 0.2 can be initially assumed and checked after preparation and testing. 61. Number of sampling units and increments: 62. **a) Continuous sampling** According to formula (16) to calculate the initial sampling units: \...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (16) Where: m - number of initial sampling units; M - Batch of coal quantity, unit for tons (t); M0 - start sampling unit coal quantity, unit for tons (t).). Large quantities of coal (such as a ship carrying coal)Take 5000 t; small quantities of coal (such as trains, cars and barges carrying coal)Take 1000t. Formula (17) is used to calculate the number of increments per sample unit, n \...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (17) If the calculated value of n is infinite (∞) or negative, It is proved that sample preparation and laboratory variance is large, at the set number of sampling units (m) Not to the required precision. At this time, or when n is large enough to be impractical, Use one of the following methods to increase the number of sampling units m:: Estimate an appropriate m value, and then use formula (17) to calculate the N, such as the calculation of the n is still not suitable, then given a m value, to re calculate the N, until it can be accepted; Or set an acceptable maximum n value, and then use the formula (18) to calculate the m:: \...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (18) If desired, you can transfer large m value to an appropriate value, and then recalculate n. When n is less than the calculated 10, take n = 10. When a number is greater than the amount of the initial sampling unit (1000t or 5000t) of coal as a sampling unit sampling, according to formula (19) to calculate the number of increments: \...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (19) When a batch is less than the amount of the initial sampling unit coal as a sampling unit sampling, the number of increments may be decreasing proportion, but each Increment combined into the total sample mass should be consistent with the provisions of Tables 4 and 5, and the minimum number of increments not less than 10. **b) Intermittent sampling** The total number of sampling units sampling units are located m, need to be sampled for u, then according to formula (20) to calculate n: \...\...\...\...\...\...\...\...\...\... (20) If the calculated n is infinite or negative, it is proved that the sample preparation and laboratory variance is large, the actual number of sampling units has been set u, the required precision, this time, or when n large unrealistic , Increase the number of actual sampling units u by one of the following methods. Set a larger value of u, then according to formula (20) to calculate n, and repeat this process until the value of n is acceptable so far; Setting an actual or maximum acceptable values ​​of n, and calculated by the equation (21) u:....................................... (21) If desired, you can transfer large u value to an appropriate value (sometimes also need to transfer large m value), then according to formula (20) to calculate n. When n is less than 10, take n = 10. 63. Determination of the number of sampling units and the number of increments under which VI, Vm and VPS +are unknown VI, Vm, and VPS are unknown, the number of sampling units and increments are determined in one of the following ways:: a\) Let VI = 20, Vm = 5 and VPT = 0.2, respectively, according to formula (16) to (21) determines the number of increments and sampling units per sample unit, and after sampling precision sampling be checked, adjust m, u and n when needed ; b\) The total sample size analysis of Increment number starting number 25. 64. Determination of the minimum mass of total and increment The mass of total sample and Increment is determined by 5.2.4. 6. **Sampling -- Method of taking primary increment** 65. **Moving coal flow sampling method** 66. Mobile coal flow sampling can be in the coal flow in the fall or the coal flow on the belt. For safety reasons, this standard is not recommended for coal flow on the belt. Sampling can be carried out in a systematic manner or in a stratified random sampling manner by means of a time base or mass basis. From the point of view of operating convenience and economy, time base sampling is better. While Sampling, should try to intercept a complete cross-section of the coal stream segment as an increment, Increment or samples cannot be filled from the overflow sampler. The samples should be taken from the coal flow with a uniform velocity and load. We should try to avoid running cycle of coincidence of coal flow load and quality change cycle and sampler, In order to avoid sampling bias. If unavoidable, it should be stratified random sampling method. 67. **[Falling stream sampling]** The method is **not applicable to the system of coal flow in 400t/h or more.** The coal sample is taken in the falling coal flow at the transfer point of the conveyor belt. When sampling, the sampling device shall cut the coal flow transversely at a constant speed of less than 0.6 m / s as far as possible. Sampler coal openings should be at least 3 times the nominal top size but not less than 30mm, the sample should be large enough capacity, and it is not filled fully with the Increment. The Increment should be taken out without any loss from increment. When sampling, to make a sampling bucket along the length or thickness direction of coal flow through the coal flow interception of a sub sample. For safety and convenience, the sampling bucket can be arranged on a support frame, and along the rail bracket from left to right (or vice versa) or to the past (or vice versa) mobile samplingSampling System **6.1.2.1 System sampling** 68. Increment distribution Primary Increment should be evenly distributed throughout the sampling unit. The Increments are taken at pre-set intervals (time base samples) or mass intervals (mass basis samples), the first increment is taken at random in the first time / quality interval, the remaining increments are taken at equal time / quality intervals. Increment at a pre-set time interval (sampling time base) or mass interval (mass-based sampling) to take the first random Increment taken in the first a time / quality interval, the remaining Increment equal time / quality interval take. In the whole process of sampling, speed of sampling across the coal flow should be kept constant. If the number of increments are enough as pre calculated, but the sampling unit coal stream has not yet finished, it should continue at the same time / quality sampling interval, until the end of the coal flow. In order to ensure that the actual number of increments is not less than the specified minimum number of increments, the actual increment time / mass interval shall be equal to or less than the calculated increment interval. 69. **Increment interval** The increment interval at the time of system sampling is determined as follows: **a) Time-based sampling** Take Increment interval △ t (min) according to formula (22) Calculated:......................................................... (22) Where: *m~sl~* - The amount of coal sampling unit, tones (t); *G* - Maximum flow of coal, tones per hour (t / h); *n* - The total number of increments. **b) Mass based sampling** Take the kind of quality child spacing △ m (t) according to equation (23) calculated as follows:............................................................ (23) Where: *m~sl~* - The amount of coal sampling unit, tones (t); *n* - The total number of increments. 70. Increment mass: Increment is directly proportional to the quality of the coal flow. Primary Increment mass should be greater than the formula (10) the calculated value. 71. Stratified random sampling 72. Outline Coal quality sampling process of cyclical changes may occur, should be avoided periodicity and Increment taken cycles coincide, otherwise it will bring an unacceptable sampling bias. To this end it may be stratified random sampling method. Stratified random sampling is not a time based or mass based sampling. But, increments are taken at random time or mass with a pre-defined time or mass interval. In stratified random sampling, the two Increments belonging to different time or mass intervals are likely to be very close, so the primary sampler unloader should accommodate at least two Increments. 73. Increment distribution The samples are taken at random intervals (time base samples) or mass intervals (mass basis samples) at preset intervals. 74. Increment interval Increment interval is determined as follows when stratified random sampling: a\) Time-based sampling: According to formula (22), calculate the sampling time interval. Dividing each time interval from 0 to the end of the interval (s or min) into segments, and then use a random method, Such as drawing lots, Decides the sampling time period in each time interval, and the increments are taken at this time. **b) Mass base sampling:** According to formula (23), calculate the quality of the sampling interval. The mass (t) number of each mass interval from 0 to the end of the interval is divided into several segments, and then with a random method, Such as draw, Sampling mass segments in each mass interval, and at this mass interval increments taken. 75. 76. Outline Some sampling methods tend to collect excessive large or small coal, so it is possible to introduce bias. **The ideal sampling method is the stop belt sampling method.** It takes a whole cross section as a sample from the stop belt, Is the only way to ensure that all particles are collected, So that there is no bias in the method, it is a reference method for checking other methods. But in most of the conventional sampling, Stop belt sampling operation is not practical. Therefore**, this method is only used as a reference method in bias test.** 77. Increment taken The stop belt sample is taken in a fixed position with a dedicated sampling frame (see Fig. 2g). The sampling frame is composed of two parallel side plates**, the distance between the plates is at least 3 times the nominal top size of the sampled coal and is not less than 30mm**, and the bottom edge of the side plate is similar to the belt arc. At the time of sampling, the sampling frame is placed on the coal flow of the stationary belt, and the side plate is vertical to the center line of the belt. The edge plate is inserted into the coal flow to the bottom edge and the belt is contacted, and the coal is collected on both sides of the board. The side plate is inserted into the block processing of coal particles according to the left or right to take the opposite way, that is to stop the left side of the board to insert the coal samples, to prevent the insertion of coal particles on the right side of the board, or vice versa. Choose how to start sampling, in the whole process of sampling also how to choose. The coal that is stuck on the sample frame should be blown into the sample. 78. **Stationary coal sampling methods** 79. The standard stationary coal sampling method is suitable for the sampling of coal and coal piles in trains, cars, lighters, ships, etc\... Stationary coal sampling should be carried out in the process of loading / unloading of coal If do not have the conditions of sampling in coal loading or unloading process, this process can also be used for direct sampling of stationary coal. **When sampling directly from the stationary coal, samples of full depth or different depths (upper, middle, lower or upper and lower) shall be taken.** In order to ensure that the quality of coal in the vehicle is uniform and no difference in coal quality. When loading, it is also possible to sample from the top of the vehicle. No matter what type of sampling, the bias test should be adopted to prove that there is no substantial bias. In the case of coal sampling from the top of the train, car and barge, after loading (ship), the sample should be taken immediately. In the case of sampling after transport, should be digging to 0.4m \~ 0.5m for sampling, sampling should be rolled in the bottom of coal gangue and clean. Increment should be as uniformly arranged on the surface of the sample, pay attention to the accumulation of large pieces during processing (such as loading and unloading) the segregation caused (for example, near the car horn or car wall Accumulation). Probe for manual sampling / drill or shovel opening should be at least three times the nominal top size of coal and not less than 30mm (see 9.1), sampler capacity should be large enough to take the sample mass, should meet the requirements of 5.2.4.2. When sampling, the sampler should not be full of increment or from the overflow, and a sample should be taken out carefully without losing any coal. When taking a sample, the probe / drill or shovel should be inserted perpendicular (or at an angle) from the sampling surface. While taking the sample, large pieces should not be deliberately pushed aside. The number of sampling units, the number of increments, the minimum mass of the increment, and the minimum mass of the total sample are given in 5.2.3 (or 5.3.2.4) and 5.2.4. 80. 81. Increment Distribution method 82. System Sampling method:???? Sample car / barge surface is divided into a number of small blocks of equal size and numbered, Then, one increment is taken in turn from the middle of each block of each car / boat, The first increment is taken randomly from the first car / boat, the remaining sample sequences are taken in turn from the successor car / boat**.** 83. Random sampling method The sample car / barge surface is divided into several small blocks and numbered. Make a number equal to the number of small pieces of the brand and number, a brand corresponds to a small piece. Put the sign in a bag. When determining the subsampling position of the first sampling vehicle / vessel, Take out a number from the bag equal to the number of increment to be taken from the vehicle / vessel, And from the corresponding with the corresponding small sample to take samples, And then the extracted brand into another bag; When the increment position of the second sampling vehicle / vessel is determined, From the remaining brand of the original bag, Take a number equal to the number of increment to be taken from the vehicle / vessel, And take a sample from the corresponding tile. In the same way, the sub-sample locations of the other vehicles / boats are determined. When the original bag brand finished, in turn, from another bag brand, and then back into the original bag. If it turns, until the sample is completed. Above the pumping operation can also be completed before the actual sampling, Make a note of the vehicle / ship number to be sampled and its increment location. The actual sample taken by the recorded vehicle / ship and its increment location to take samples. 84. **Sampling Train** 85. Selection of compartments When the required number of increments is equal to or less than the number of cars of a sampling unit, should take an increment from each car; When the number of increments required more than the number of cars of sampling unit, increments from each car equal to the total number of increments divided by the number of cars, as the divided remainder, the remainder to be distributed throughout the Increment sampling unit. Distribution remainder Increment compartment can be used to select a systems approach (such as every several cars collected by a increment) or with a random selection method (see 6.2.2.1.2). 86. Increment location selection????? Increment position should be individually in different compartments. In each part of the carriage, coal has the same chance of being collected. Commonly used methods are as follows: a**) Systematic sampling method**: This method applies only to the circumstances of each vehicle to take equal Increment. The car is divided into several side length of 1m \~ 2m pieces and compiled on the number (Figure 1), the number of samples in the car every time more than two, but also the successive number of mining and desire equal number of Increment number grouped together and numbered. If the 3 increments from each car, it will be 1, 2, 3 for the first group, 4, 5, and 6, compiled for the second group, and so on. First determine the first car with a random method of sampling location or group location, and then follow the sequence of points or groups of numbers in succession, from the subsequent trunk in turn take increment. b**) Random sampling methods**: the car is divided into several side length of 1m \~ 2m pieces and compiled on the number (usually 15 or 18, 18 in Figure 1 is an example. And then randomly select the sampling point location of each compartment --- --- --- ---- ---- ---- 1 4 7 10 13 16 2 5 8 11 14 17 3 6 9 12 15 18 --- --- --- ---- ---- ---- Figure 1: Distribution diagram of train sampling increments 87. **Sampling of vehicles and other small vehicles** 88. Selection of carriage Select the following cars: a. The car with a load of more than 20t, choose the car by train sampling method. b. For vehicles with a load of 20 tons or less, the compartments are selected as follows: 89. Increment location selection Increment position sample selection is same as train. 90. Barge sampling: The sub-sample distribution of barge sampling is the same as that of train sampling, so barge sampling may be carried out as described in 6.2.2.2. 91. Ship sampling: Due to technical and safety reasons, this standard does not recommend sampling directly from a ship\'s cabin. Ship loading or unloading should be sampled, when in its loading (unloading) coal streams or small vehicles such as the car performed. 92. **Sampling coal piles:** 93. Outline [Sampling should be in the coal pile piles stack or unloading process, or in the process of migrating the coals, Increment taken in the following manner: ] [In coal flow on the conveyor belt, small vehicles such as automobiles, heap / unloading process in each work on the new surface layer, and removing the loader bucket and not just remove the main heap coals merge small Increment taken on the coal. ] [**Do not sampled directly on the stationary height of more than 2m large coal pile**. The procedure described in (6.2.2.6.2a) can also be used when sampling from the surface of a stationary large coal mass, but the results are highly likely to be biased and the precision is poor. From the quiescent coal pile, coal samples cannot be arbitrated.] 94. Increment arrangement The following Increment arrangement: a\) In the pile / coal unloading new face, just unloaded small coal sample, according to the shape and size of the coal pile dividing the surface of the work surface or coal into a number of areas, and then dividing the area into a number of equal area (the bottom of the coal pile should be from the ground 0.5m), Then, the sampling area and the location of each sampling point (small) are determined by the sampling method and the random sampling method, to take 1 full or deep or top coal samples from each small piece, In the case of non-new working face, The surface layer of 0.2m should be removed first. b\) When unloading coal in a bucket loader, unload the coal sample on a clean surface, and then take a sample. 7. **Intermittent sampling methods (sample from few sampling units)** When the same source of coal, quality and stability of large quantities of coal (such as port coal) for sampling, the sampling method can be intermittent. The consent of the interested party shall be obtained in advance for the intermittent sampling method. Design of intermittent sampling scheme according to B 5.3.2.4.1. 8. **Various coal samples taken** Coal samples for industrial analysis (for general physics of coal, test sample for determination of chemical properties, Total moisture sample (specifically for the determination of total moisture), Common sample (for various purposes, such as total moisture and general physics, Samples taken for determination of chemical properties, Physical sample (specifically for special physical characteristics, Sample, such as physical strength index or particle size analysis.). Samples for the determination of total moisture can be taken separately, or can be extracted from a common sample. In the case of a moisture sample taken from a common sample, the number of primary increments taken shall be the larger of the number of ash or moisture required, if the residual sample is insufficient after removal of the moisture sample test the mass, you should increase the number of increments to the total sample mass to meet the requirements.. Where necessary (e.g., very wet coal), a separate moisture sample may be taken. When taking moisture samples separately, the following points should be considered: a. Coal storage due to discharge water gradually lose moisture; b. If free water is present in the batch coal, it will sink to the bottom, so the water content increases progressively as the depth of the coal increases. c. If moisture samples are taken from a number of lots over a long period of time, it is necessary to limit the sample placement time. Therefore, the best approach is to take increments from different water levels of each sampling unit within a limited time. 9. **Manual sampling method** 95. **The basic requirements for manual sampling method** The basic requirements of Manual sampling tool are: a. The width of the opening of the sampling device shall meet the requirements of equation (24) and not less than 30 mm: *W*≥3d\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\... (24) Where: *W* - The minimum width of the cross section of the opening of the sampling device, the unit is mm (mm); *d* - Coal nominal top size, in millimeters (mm). b\) The appliance shall have a capacity to accommodate at least one sample of coal and shall not be filled with the sample and the coal shall not spill or leak from the appliance; c\) For flow sampling, **the length of the sampler opening is greater than the full width of the intercepted coal stream (**when moving back and forth) or full thickness (when moving left and right); d\) While taking Increment, large piece of coal or waste rock will not be pushed to the side; e\) Wet coal adhering to the appliance should be minimal and easy to remove. 96. **Example** Figure 2 shows an example of the Increment taken appliances: Sampling bucket, sampling shovel, probe, hand auger, bucket manual cut, stop with the sampling frame. 97. The sampling bucket (see Figure 2 a) is made of stainless steel, which is not easily adhered to coal, and is suitable for sampling from a falling coal stream. 98. The sampling shovel (see Fig. 2b) is made of steel plate and is equipped with a handle of sufficient length. The size of the spatula can be adjusted accordingly for coal samples of other particle sizes. The bottom head can be pointed shovel. 99. The probe is generally tubular, and can be inserted into coal in a vertical or small angle. When the pipe is inserted into the coal, it may be more difficult, when the coal is pulled out from the coal, the coal may fall from the bottom. Several kinds of probes are available for the use of coal with a nominal maximum size of 25mm. Fig. 2 c): it is composed of two and half circular tubes, two and half tubes can be slid together and form a closed circular tube. The maximum length of the pipe can be 3.5m; the long probe can be used for the maximum size of 20mm coal. Figure 2 d): The probe consists of a triangular groove with a chute on both sides and a plate that slides along the chute. When in use, the sliding board is taken down, and the groove tube is inserted into the coal, and then slide back into place, and the pipe is pulled out. 100. Fig. 2 e): the opening and pitch of the drill should be 3 times the nominal maximum size of the sampled coal. 101. Figure 2f): for manual or mechanical assistance, the falling coal flow sampling. 102. Figure 2g): The sampling frame consists of two parallel side panels, the distance between the board is at least three times the nominal maximum particle size of the sampled coal (but not less than 30mm), the edge of the edge of the edge of the curvature of the belt and the belt is similar. 人工采样图2a-采样斗 Figure 2 a) sampling bucket Millimeters  Figure 2 b) Sampling shovel (for a nominal maximum particle size of 50mm) Figure 2 c) circular probe Millimeters  Figure 2 d) triangular grooved probe Figure 2 e)Hand auger  Figure 2 f) manual cutting bucket Figure 2 g) stop sampling frame 10. **Coal sample packaging and labeling** The coal sample shall be packed in an airtight container which is non-adsorptive and non-corrosive and shall have a permanent unique identification mark. The following information shall be included in the coal sample label or accompanying documentation: a\) The type, grade and nominal maximum particle size of the coal and the name of the batch (ship or train name and frequency); b\) Type of coal sample (general coal sample, moisture coal sample, etc.); c\) Sampling location, date and time. 11. **Sampling report** Sampling should be formally issued, comprehensive sampling and sample delivery reports or certificates. The sampling report or certificate shall include all the information as mentioned in the tenth 10, and shall include the following: a. Name of the report; b. The principal\'s name, address; c. Sampling methods; d. Approximate mass of coal and number of sampling units e. Number of Increments and the total sample mass; f. Sampler name and number; g. climate and other conditions that may affect the results of the experiment; h. Test specimens, samples and arbitration longest shelf life\'s copy of the sample; i. In the Sampling, reasons for any deviation from the prescribed method of sampling and observed any abnormalities. Sampling report information should be accompanied by samples, or notify the sample preparation staff.