British Chemical Standard – bottles of 100g chips graded 1700 - 250µm (10 - 60 mesh) for chemical analysis. Page 2 of 2 BCS-CRM No. 206/3 (ECRM 453-1) HIGH Si and P CAST IRON NOTES ON METHODS USED SILICON Analysts Nos. 1, 3, 4, 5, 6 and 7 determined silicon gravimetrically by the British Standard Silicon Method l*. No. 2 used a titrimetric method based on the formation of potassium fluorosilicate which is filtered off and titrated with standard alkali (Sneddon, Foundry Trade J., 1966, 120, 605-7). Analyst No. 2 also determined silicon gravimetrically by dehydration with perchloric acid and found 3.13%. MANGANESE Analysts Nos. 1, 3 and 4 determined manganese titrimetrically. Nos. 1 and 4 used Analoid methods, oxidising with persulphate/silver nitrate and titrating with arsenite/nitrite solution (No. 1) or arsenite solution (No. 4). No. 3 used the British Standard Manganese Method 1* which includes a zinc oxide separation. Nos. 2, 5, 6 and 7 determined manganese photometrically after oxidation with periodate; Nos. 6 and 7 used the British Standard Manganese Method 2*. Analyst No. 3 also used an Analoid titrimetric method and found 0.72%. PHOSPHORUS Analysts Nos. 1, 2, 4, 5, 6 and 7 determined phosphorus titrimetrically after precipitation as phosphomolybdate. Nos. 1 and 2 precipitated according to the British Standard Phosphorus Method 1*. Nos. 4 and 7 used the Analoid method. No. 3 used the British Standard Phosphorus Method 1*. and completed gravimetrically as lead molybdate. Analysts Nos. 1 and 3 also used the titrimetric Analoid method and found 1.64% and 1.65% respectively. No. 7 also determined phosphorus photometrically as phosphovanadomolybdic acid and found 1.66%. SULPHUR Analysts Nos. 1, 3 and 4 determined sulphur gravimetrically. No. 1 first carried out a chromatographic separation on an alumina column (Nydahl, Anal. Chem., 1954, 26, 580). Nos. 3 and 4 used the British Standard Sulphur Method 1*. The other Analysts determined sulphur by combustion. No. 2 used an air combustion method (Green, BCIRA Journ., 1968, 16, 244). No. 5 used the Strohlein method. Analyst No. 3 also used a combustion method and found 0.050%. CHROMIUM All Analysts except Nos. 4 and 5 determined chromium photometrically with diphenylcarbazide. Nos. 1 and 6 used the Analoid method No. 51. No. 2 carried out a preliminary extraction of iron with iso-butyl acetate (Scholes and Smith, Metallurgia, 1963, 67, 153). Nos. 3 and 7 used the British Standard Chromium Method 2*. No. 4 determined chromium titrimetrically according to the British Standard Chromium Method 1*. No. 5 used the titrimetric Analoid method No. 37. NICKEL All Analysts determined nickel photometrically with dimethylglyoxime. No. 1 carried out a preliminary separation of the bulk of the iron by extraction into diethyl ether. Nos. 3, 4, 6 and 7 used the British Standard Nickel Method 3*. ARSENIC All Analysts precipitated elemental arsenic by hypophosphite reduction and determined it iodimetrically. Nos. 3, 4 and 6 used the British Standard Arsenic Method 1*. COPPER All Analysts except No. 2 determined copper photometrically. Nos. 1 and 4 used the bis-cyclohexanone oxalyldihydrazone method (Haywood and Sutcliffe, Analyst, 1956, 81, 651). Nos. 3, 6 and 7 used 2-2' diquinolyl according to the British Standard Copper Method 3*. No. 2 determined copper by atomic-absorption spectroscopy. Analyst No. 3 also used the bis-cyclohexanone oxalyldihydrazone method and found 0.105%. VANADIUM Analysts Nos. 1 and 2 determined vanadium photometrically. No. 1 used a phosphovanadotungstate method after separation of the iron by extraction into diethyl ether. No. 2 used the hydrogen peroxide method after bleaching the titanium colour with fluoride. The other Analysts determined vanadium titrimetrically. Nos. 3, 4, 6 and 7 used the British Standard Vanadium Method 1*. No. 5 used the Analoid method No. 34. TOTAL CARBON All Analysts determined carbon by combustion. Nos. 1, 3, 5 and 6 completed gravimetrically according to the British Standard Carbon Method 1*. No. 2 completed by non- aqueous titration (Jones et al., Analyst, 1965, 90, 623; 1966, 91, 399) and No. 7 by infrared absorption. Analyst No. 3 also used the non-aqueous titration method and found 2.45%. GRAPHITIC CARBON The graphite was separated by decomposing the sample with dilute nitric acid and filtering; the carbon in the residue was determined gravimetrically by combustion according to the British Standard Carbon Method 2*. TITANIUM Titanium was determined photometrically with hydrogen peroxide after separation with cupferron. *Methods for Sampling and Analysis of Iron, Steel and Other Ferrous Metals, B.S. Handbook No. 19, first published in 1970 by the BSI, 389 Chiswick High Road, London. W4 4AL.

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