YS/T 271.1-1994 PDF English

YS/T271.1-1994 (YST271.1-1994): PDF in English

YS/T 271.1-1994 (Renamed from GB 8150.1-87) GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA UDC 622.765.06.543.06 YS/T 271.1-1994 Renamed from GB 8150.1-87 Methods for chemical analysis of xanthates – The lead-acetate titration method for determination of xanthate content APPROVED ON. JANUARY 27, 1987 IMPLEMENTED ON. JUNE 01, 1988 Issued by. China Non-ferrous Metal Corporation Table of Contents 1 Method summary ... 3  2 Reagents ... 3  3 Analytical procedures ... 5  4 Calculation of analytical results ... 6  5 Allowable difference ... 6  Additional information... 7  Methods for chemical analysis of xanthates – The lead-acetate titration method for determination of xanthate content This standard complies with GB 1467-78 “Method for chemical analysis of metallurgy product - General rules and regulations”. This method is applicable to the determination of the amount of xanthogen in ethyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl and other sodium xanthate or potassium xanthate of lower carbon alkyl group. 1 Method summary The sodium nitro-ferrocyanide is used as an indicator, the potassium ferricyanide is used to oxidize impurities such as alkali metal sulfides in xanthate into monomer sulfur to eliminate interferences. The chemical reaction is. Then the sodium rhodizonic acid is used as an indicator, and the lead acetate standard solution is used to titrate the sodium xanthate. The chemical reaction formula is. 2 Reagents 2.1 Hydrochloric acid (specific gravity 1.19). 2.2 Hydrochloric acid (6N). 2.3 Glacial acetic acid. 2.4 Aqueous ammonia solution (10%). 2.5 Ammonium-ammonium chloride buffer solution. Prepared in accordance with clause 38 (1) of GB 603-77 “Chemical reagent - Preparations of reagent solutions for use in test methods”. beaker continuously, ADD potassium ferricyanide (2.7) in drops, until the blue- purple color of the specimen solution disappears, then ADD one more drop, to ensure complete oxidation. If potassium ferricyanide (2.7) is added in excess of 1 ml, TAKE another 5.00 ml of specimen solution into a 250 ml beaker, ADD approximately 0.2 g of ammonium chloride, REPEAT the above operations to remove the sulfide impurities. ADD 100 ml of water into the beaker, whilst stirring it, USE the lead acetate standard solution (2.16) to titrate it, when approaching to the end point, ADD 1 ~ 2 ml of sodium rhodizonic acid indicator solution (2.11), CONTINUE titration until the meat red color suddenly appears, as the end point. 4 Calculation of analytical results CALCULATE the percentage of xanthogenate by the following formula. Xanthogenate content (%) = (N • V • M/1000)/(5W/500) x 100 Where. N - Gram equivalent concentration of lead acetate standard solution; V - Lead acetate standard solution consumed during titration, ml; M - Molecular weight of xanthogenate; W - Weighed specimen weight, g. The molecular weights of several common xanthogenates are as follows. Sodium ethyl xanthogenate. 144.2 Sodium isopropyl xanthogenate. 158.2 Sodium m-butyl xanthogenate. 172.3 Sodium isobutyl xanthogenate. 172.3 Sodium amyl xanthogenate. 168.3 Sodium isoamyl xanthogenate. 168.3 5 Allowable difference The allowable difference of the parallel determination in this method is not more than 0.5%. .......
Source: https://www.ChineseStandard.net/PDF.aspx/YST271.1-1994