GB 474-2008 PDF EnglishUS$135.00 · In stock · Download in 9 seconds
GB 474-2008: [GB/T 474-2008] Method for preparation of coal sample Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid GB 474: Historical versions
GB 474-2008: [GB/T 474-2008] Method for preparation of coal sample---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GB474-2008D 21 NATIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA GB474-2008 Replacing GB 474-1996 Method for Preparation of Coal Sample (ISO 18283.2006, Hard Coal and Coke-Manual Sampling, MOD) Issued on. DECEMBER 04, 2008 Implemented on. MAY 01, 2009 Jointly Issued by. General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China; Standardization Administration of the People's Republic of China. GB Table of ContentsForeword... I 1 Scope... 1 2 Normative References... 1 3 Terms and Definitions... 1 4 General and Precision of Sample Preparation... 2 4.1 General of Sample Preparation... 2 4.2 Sample Preparation Precision... 3 5 Apparatus... 3 6 Constitution of Sample... 4 7 Division... 5 7.1 General... 5 7.2 Minimum Mass of the Divided Sample... 5 7.3 Mechanical Methods... 6 7.4 Manual Methods... 12 8 Reduction... 15 9 Mixing... 16 10 Air-drying... 16 11 Preparation of Various Coal Samples... 17 11.1 Types of Coal Sample... 17 11.2 Moisture Sample of Coal... 17 11.3 General-analysis Test Sample of Coal... 19 11.4 Common Sample of Coal... 21 11.5 Size Analysis Sample of Coal... 22 11.6 Coal Samples for other Tests... 22 12 Reserve Sample... 23 Appendix A (Informative) Comparison of Chapter and Article Numbers between this Standard and ISO 18283.2006(E)... 24 Appendix B (Informative) Technical Differences between this Standard and ISO 18283. 2006(E) and the Reasons... 26 Appendix C (Normative) Verification for Precision of Sample Preparation and Assays and Bias Test... 28 Appendix D (Normative) Method for Flotation of Coal Sample... 30 IForeword Chapter 4, Chapter 6, Chapter 7, Chapter 10 and Chapter 11 of this standard are mandatory and the others are recommendatory. This standard is modified in relation to ISO 18283.2006(E) "Hard Coal and Coke-Manual Sampling" (English version). This standard was re-drafted mainly according to ISO 18283.2006(E). The list for comparison of chapter and article numbers between this standard and ISO 18283.2006(E) is given in Appendix A. In consideration of the national condition of China, this standard is subjected to some modifications in the adoption of ISO 18283.2006(E). Technical differences have already been incorporated into the text and marked with perpendicular single line at the margin of relevant clauses. The list for these technical differences and their reasons is given in Appendix B for reference. For convenient application, some editorial changes are made to ISO 18283.2006(E) as follows. ——"This international standard" is replaced by "this standard"; ——Introduction of ISO 18283.2006(E) is modified; ——Comma ",", which serves as decimal point in ISO standard, is replaced by ".". This standard replaces GB 474-1996 "Preparation of Coal Sample". Compared with GB 474-1996, main changes of this standard are as follows. ——Contents on general and precision of sample preparation (Chapter 3 of the original edition and Chapter 4 of this edition) are improved; ——Contents on sample constitution are added (Chapter 6 of this edition); ——"Coal sample greater than 25mm (particle size) shall not be divided before being crushed" is modified into "division may be carried out at any stage and the minimum mass of divided sample shall meet those specified in 7.2" (6.3 of the original edition and 7.1 of this edition); ——The minimum mass of divided sample at each particle size level is modified (6.7 of the original edition and 7.2 of this edition); ——Contents on mechanical dividing method and mechanical divider are added (7.3 of this edition); ——Two manual dividing methods are added (7.4.2 and 7.4.3 of this edition); ——Detailed explanations and specifications on division, reduction, mixing and air-drying etc. are added (Chapter 7, Chapter 8, Chapter 9 and Chapter 10 of this edition); ——Preparation methods of various coal samples are added (Chapter 11 of this edition); ——Operating requirements for extracting moisture sample of coal from common sample of coal with the nine-point picking out method are defined (11.4.1 of this edition). Appendix A and Appendix B of this standard are informative, Appendix C and Appendix D of this standard are normative. This national standard is proposed by the China National Coal Association. This standard is under the jurisdiction of the National Technical Committee on Coal Chemical Industry of Standardization Administration of China. Drafting organization of this standard. Coal Analysis and Test Laboratory of China Coal Research Institute (National Quality Supervision and Inspection Center for Coal). Chief drafting staff of this standard. Han Liting, Pi Zhongyuan, Duan Yunlong. The previous editions replaced by this standard are. ——GB 474-1964; GB 474-1975; GB 474-1983; GB 474-1996. 1NATIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA Method for Preparation of Coal Sample1 ScopeThis standard specifies terms and definitions, sample constitution, reduction, mixing, division and air-drying for coal sample preparation, the preparation of various coal samples and reserve sample. This standard is applicable to lignite, bitumite and hard coal.2 Normative ReferencesThe following documents contain provisions which, through reference in this standard, constitute provisions of this standard. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, its latest editions apply. GB/T 211 "Determination of Total Moisture in Coal" (GB/T 211-2007, ISO 589-2003, NEQ)3 Terms and DefinitionsTerms and definitions specified in GB 475 and those below are applicable to this standard. Method of sample division in which the mass retained is predetermined and independent of the mass of the divided sample.4 General and Precision of Sample PreparationAccording to formulae given in GB 475, and in continuous sampling, the fiducial probability, at 95%, of the precision estimated (absolute) value PL for the determination results of coal in one lot is shown in Formula (1).5 ApparatusThe sample preparation room shall have cement floor. And the cement floor in the area for coning-and-mixing division shall also be paved with the steel plate with the thickness greater than 6mm. The room storing coal sample shall be free from heat source, highlighting or any chemicals.6 Constitution of SampleIndividual increments are usually constituted to form a sample. a single sample may be constituted by combination of increments taken from a complete sampling unit or by constituting increments taken from individual parts of a sampling unit (see Figure 1). Under some circumstance, e.g. size analysis and bias test, the sample consists of one single increment.7 DivisionDivision is the most important procedure for sample preparation, and the purpose is to reduce the sample amount. Division can be carried out mechanically or manually. Wherever possible, mechanical methods are preferred to manual methods to minimize human error. This method is only applied to extract total moisture sample. As shown in Figure 8, the sample shall be spread into circular shape with the thickness not greater than 3 times the nominal top size after being blended with coning and quartering method, then nine increments shall be taken from nine points shown in Figure 8 with the sampling scoop and operation similar to those used in flattened-heap method (7.4.2) so as to constitute into a total moisture sample.8 ReductionThe discharge size of the crusher depends on the type of crusher, the dimension of crushing opening (jaw crusher and roll crusher) or the speed (hammer crusher and ball crusher).9 MixingMixing is carried out to make the coal sample uniform as much as possible. In theory, thorough mixing of a sample prior to its division reduces errors due to sample preparation In practice, this is not entirely true. For example, where the mechanical divider is adopted, mixing prior to division will not only be unnecessary to ensure the division precision but also result in loss of moisture. ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of GB 474-2008 be delivered?Answer: The full copy PDF of English version of GB 474-2008 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of GB 474-2008_English with my colleagues?Answer: Yes. The purchased PDF of GB 474-2008_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. www.ChineseStandard.us -- GB 474-2008 -- Click this link and select your country/currency to pay, the exact amount in your currency will be printed on the invoice. Full PDF will also be downloaded/emailed in 9 seconds.Question 5: Should I purchase the latest version GB 474-2008?Answer: Yes. Unless special scenarios such as technical constraints or academic study, you should always prioritize to purchase the latest version GB 474-2008 even if the enforcement date is in future. Complying with the latest version means that, by default, it also complies with all the earlier versions, technically.How to buy and download a true PDF of English version of GB 474-2008?A step-by-step guide to download PDF of GB 474-2008_EnglishStep 1: Visit website https://www.ChineseStandard.net (Pay in USD), or https://www.ChineseStandard.us (Pay in any currencies such as Euro, KRW, JPY, AUD).Step 2: Search keyword "GB 474-2008". Step 3: Click "Add to Cart". If multiple PDFs are required, repeat steps 2 and 3 to add up to 12 PDFs to cart. Step 4: Select payment option (Via payment agents Stripe or PayPal). Step 5: Customize Tax Invoice -- Fill up your email etc. Step 6: Click "Checkout". Step 7: Make payment by credit card, PayPal, Google Pay etc. After the payment is completed and in 9 seconds, you will receive 2 emails attached with the purchased PDFs and PDF-invoice, respectively. Step 8: Optional -- Go to download PDF. Step 9: Optional -- Click Open/Download PDF to download PDFs and invoice. See screenshots for above steps: Steps 1~3 Steps 4~6 Step 7 Step 8 Step 9 |
