GB/T 14635-2020 PDF EnglishUS$205.00 · In stock · Download in 9 seconds
GB/T 14635-2020: Rare Earth Metals and Their Compounds - Determination of Total Rare Earth Content 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/T 14635: Historical versions
Similar standardsGB/T 14635-2020: Rare Earth Metals and Their Compounds - Determination of Total Rare Earth Content---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/GBT14635-2020 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 77.120.99 H 14 GB 14635-2020 Replacing GB/T 14635-2008 Rare Earth Metals and Their Compounds - Determination of Total Rare Earth Content Issued on. NOVEMBER 19, 2020 Implemented on. OCTOBER 01, 2021 Issued by. State Administration for Market Regulation; Standardization Administration of PRC. Table of ContentsForeword... 3 1 Scope... 6 2 Method-1.Oxalate Gravimetric Method... 7 3 Method-2.EDTA Titration Method... 14 4 Quality Assurance and Control... 211 ScopeThis Standard specifies the determination method of total rare earth content in the rare earth metals and their compounds. This Standard is applicable to the determination of the total rare earth content in rare earth metals and their compounds. This Standard contains two methods. Method-1 is oxalate gravimetric method, and Method-2 is EDTA titration method. Method-1 is applicable to the determination of the total rare earth content in single and mixed rare earth metals and their compounds; the determination range is shown in Table 1; it is not applicable to the determination of the total rare earth content in single and mixed rare earth metals and their compounds mainly based on erbium, thulium, ytterbium, and lutetium or the individual content of thorium and lead is greater than 0.1%. Method- 2 is applicable to the determination of the total rare earth content in the single rare earth metals and mixed rare earth metals and their compounds mainly based on heavy rare earth holmium, erbium, thulium, ytterbium, and lutetium; the determination range is shown in Table 2; it is not applicable to the determination of the total rare earth content in the single rare earth with relative purity less than 99.5%, as well as in a single rare earth metal and its compounds with other impurity elements greater than 0.5%; it is also not applicable to the determination of the total rare earth content in materials with individual content of thorium, scandium, and zinc greater than 0.1%. 2 Method-1.Oxalate Gravimetric Method 2.1 Principle of method After the specimen is decomposed by acid, the rare earth is precipitated in ammonia water to separate calcium and magnesium. 2.2 Reagents and materials 2.2.1 Perchloric acid (ρ=1.67g/mL). 2.2.2 Hydrogen peroxide (30%). 2.2.3 Hydrochloric acid (1+1). 2.2.4 Nitric acid (1+1). 2.2.5 Ammonia water (1+1). 2.2.6 Oxalic acid solution (50g/L). 2.2.8 Oxalic acid lotion (2g/L). 2.3 Apparatus 2.4 Specimen 2.4.1 The oxide layer on the surface shall be removed from the metal specimen and weigh immediately after sampling. 2.5 Analytical procedures 2.5.1 Testing materials Weigh the specimen (2.4) according to Table 4, accurate to 0.0001g. 2.5.2 The number of determinations Weigh two portions of testing materials for parallel determination, and take the average value. 2.5.3 Determination 3 Method-2.EDTA Titration Method 3.1 Principle of the method The testing materials are dissolved in acid; and sulfosalicylic acid is used to mask the ions e.g., ferric ion, etc. Under the condition of pH 5.5, xylenol orange is used as an indicator; and use the EDTA standard solution to titrate the rare earth. 3.2 Reagents 3.3 Specimen 3.3.1 The surface oxide layer shall be removed from the metal specimen; and weigh immediately after sampling. 3.3.2 There are many types of rare earth compounds and their chemical properties are different. The basic state of the different compound specimen to determine the total rare earth content is difference. The basic state of measurement for each different compound is shown in Table 8.There are usually 3 ways. 3.4 Analysis procedures 3.4.1 Testing materials Take the specimen (3.3) according to Table 9, accurate to 0.0001g. 3.4.2 The number of determinations Weigh two specimens for parallel determination, and take the average value. 3.4.3 Determination 3.4.3.1 Dissolution of the testing materials 3.4.3.1.5 Dissolution of rare earth chloride. place the testing materials (3.4.1) in a 200mL beaker; add 20mL of water, 10mL of hydrochloric acid (3.2.5); cover with a watch glass; and take it off and cool to the room temperature after heating at low temperature to dissolve completely. Transfer the solution into a 200 mL volumetric flask; dilute to the mark with water, and mix well. 3.5 Calculation and expression of analysis results 3.5.1 Calculation and expression of the total rare earth content in rare earth metal testing materials 3.5.2 Calculation and expression of the total rare earth content in the rare earth compound testing materials The determination results of the total rare earth content in each rare earth compound are all the total rare earth content in the specimens with corresponding measurement basic state. The total rare earth content is calculated by the mass fraction w (REO) of rare earth oxide (REO), which is calculated as per Formula (5). 3.5.3 The calculation and expression of the total rare earth content in the mixed rare earth metal testing materials with heavy rare earth holmium, erbium, thulium, ytterbium and lutetium as the main body 3.5.4 The calculation and expression of the total rare earth content in the mixed rare earth compound testing materials with heavy rare earth holmium, erbium, thulium, ytterbium, and lutetium as the main body 3.6 Precision 3.6.1 Repeatability For the measured values of two independent test results obtained under repeatability conditions, within the average range given below, the absolute difference between the two test results does not exceed the repeatability limit (r); 3.6.2 Tolerance The difference between the analysis results among laboratories shall be no greater than the tolerance listed in Table 11.4 Quality Assurance and ControlRegularly use self-made control standard sample (if there is a national or industry-level standard sample, it should be used first) to check the effectiveness of this standard analysis method once. ......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/T 14635-2020 be delivered?Answer: The full copy PDF of English version of GB/T 14635-2020 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/T 14635-2020_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 14635-2020_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/T 14635-2020 -- 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/T 14635-2020?Answer: Yes. Unless special scenarios such as technical constraints or academic study, you should always prioritize to purchase the latest version GB/T 14635-2020 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/T 14635-2020?A step-by-step guide to download PDF of GB/T 14635-2020_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/T 14635-2020". 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 |
