1、INTERNATIONAL STANDARD IS0 10213 First edition 1991-12-15 Aluminium ores - Determination of total iron content - Titanium trichloride reduction method Minerais alumineux - Dosage du fer - Mdthode de r6duction au trichlorure de titane Reference number IS0 10213:1991(E) Copyright International Organiz
2、ation for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 10213:1991(E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bo
3、dies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental
4、and non-governmental, in liaison with ISO, also take part in the work. IS0 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnlcal standardization. Drafl International Standards adopted by the technical committees are circulated to the member
5、bodies for voting. Publication as an Inter- national Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard IS0 10213 was prepared by Technical Committee ISO/TC 129, Aluminium ores, Sub-Committee SC 2, Methods of analysis. Annex A forms an Integral pa
6、rt of this International Standard. Annex B Is for information only. 0 IS0 1991 All rights reserved. No part of this publication may be reproduced or utlllzed In any form or by any means, electronic or mechanical, lncludlng photocopylng and mlcrofllm, wlthout permlsslon in writfng from the publisher.
7、 lnternatlonal Organlzatlon for Standardization Case Postale 56 l CH-1211 GenAve 20 l Swltzerland Prlnted In Swltzerland ii Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-
8、,-INTERNATIONAL STANDARD IS0 10213:1991(E) Aluminium ores - Determination of total iron content - Titanium trichloride reduction method 1 Scope This International Standard specifies a titrimetric method, free from mercury pollution, for the deter- mination of the total iron content in aluminium ores
9、, using potassium dichromate as titrant after re- duction of the trivalent iron by tin(ll) chloride and titanium(lll) chloride. The excess reductant is then oxidized by perchloric acid. The method is applicable to ores containing be- tween 2 % (m/m) and 50 % (m/m) of iron oxide (bOJ 2 Normative refe
10、rences The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the editions indicated were valid. All stan- dards are subject to revision, and parties to agreements based on this Internation
11、al Standard are encouraged to investigate the possibility of ap- plying the most recent editions of the standards in- dicated below. Members of IEC and IS0 maintain registers of currently valid International Standards, IS0 5725:1986, Precision of test methods - Determi- nation of repeatability and r
12、eproducibility for a stan- dard tesf method by infer-laboratory tests. IS0 6140:1991, Aluminium ores - Preparation of samples. IS0 8558:1985, Aluminium ores - Preparation of pre-dried test samples. IS0 8685:-l), Aluminium ores - Sampling proce- dures. 3 Principle Decomposition of the test portion by
13、 sintering with sodium peroxide followed by a brief fusion. Dissol- ution of the melt in water and hydrochloric acid. Reduction of the major portion of the iron(lll) by tin(ll) chloride and reduction of the remainder of the iron by titanlum(lll) chloride. Oxidation of the excess reductant with dilut
14、e perchloric acid. Titration of the reduced iron with potassium dichromate solution using sodium diphenylaminesulfonate indicator. 4 Reagents During the analysis, use only reagents of recognized analytical reagent grade, and only distilled water or water of equivalent purity. 4.1 Sodium peroxide, dr
15、y powder. WARNING - Sodium peroxide should be protected against humidity when stored and should not be used once it has begun to agglomerate. 4.2 Hydrochloric acid, p2c between 1,16 g/ml and I,19 g/ml. 4.3 Hydrochloric acid, p20 between I,16 g/ml and I,19 g/ml, diluted 1 + IO. 4.4 Perchloric acid, 7
16、2 % (m/m) (20 = I,67 g/ml), diluted 1 + 1. 4.5 Sulfuric acid-phosphoric acid mixture. Pour 150 ml of phoshoric acid (20 = 1,70g/ml) into about 400 ml of water while stirring, add 150 ml of sulfuric acid (2 = 1,84g/ml), cool in a water bath and dilute with water to 1 litre. 4.6 Potassium permanganate
17、, 25 g/l solution. 1) To be published. Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 10213:1991(E) 4.7 Tin(H) chloride, 100 g/l solution. Dissolve 100 g of crystall
18、ine tin(h) chloride dihydrate (SnCl,.2H,O) in 200 ml of hydrochloric acid (4.2) by heating the solution on a water bath. Cool the sol- utlon and dilute with water to 1 litre. 5.2 Burette, class A. 5.3 One-mark volumetric flasks, of capacity 1000 ml. This solution should be stored in a brown glass bo
19、t- tle with a small quantity of granular tin metal. 5.4 Muffle furnace, suitable for operation in the range 500 “C to 800 “C. 4.8 Tltanlum(lll) chloride, 15 g/l solution. Dilute 1 volume of titanium(lll) chloride solution (about 15 % TiCI,) with 9 volumes of hydrochloric acid diluted 1 + 1. Alternat
20、ively, dissolve 1 g of titanium sponge in about 30 ml of hydrochloric acid (4.2) in a covered beaker, by heating on a water bath. Cool the solution and dilute with water to 250 ml. 6 Sampling and samples 6.1 Sampljng Laboratory samples shall be taken and crushed to pass a 150 pm test sieve in accord
21、ance with the procedures specified in IS0 6140 and IS0 8685. Prepare fresh solutions as needed. 6.2 Preparation of the test sample 4.9 Iron, 0,l mol/l standard solution. Transfer 5,585 g of pure Iron to a 500 ml Erlenmeyer flask and place a small filter funnel in the neck. Add 75 ml of hydrochloric
22、acid diluted 1 -t 1 in small in- crements and heat until dissolved. Cool and oxidize with 5 ml of a 3 % (m/m) hydrogen peroxide solution added in small portions. Heat to boiling and boil to decompose the excess hydrogen peroxide and to remove chlorine. Transfer to a 1000 ml volumetric flask (5.3) an
23、d dilute to the mark with water. I,00 ml of this standard solution is equivalent to I,00 ml of the standard volumetric potassium dichromate solution (4.10). 4.10 Potassium dlchromate, standard volumetric solution, c(K v, is the volume, in millilitres, of the potassium dichromate solution used for th
24、e titration in the blank test, corrected for the iron standard sol- ution added in 7.5.4; m is the mass, in grams, of the test portion; 0,007 985 is a sub-multiple of the relative mo- lecular mass of lron(lll) oxide. 8.2 General treatment of results 8,2-l Precision A planned trial of this method was
25、 carried out by eight laboratories at five levels of iron, each labora- tory making four determinations at each level. The results obtained were treated statistically in ac- cordance with IS0 5725 and the resultant data are presented in table 1. The data obtained showed a logarithmic relationship be
26、tween iron content, repeatability (r) and repro- ducibility (X) of the test results as summarized In table I. The graphical presentation of the precision data is given in annex B. 8.2.2 Acceptance of test results (see annex A) The analytical value for the test sample shall be ac- cepted when the ana
27、lytical value obtained for the corresponding certified reference material agrees with the certified value within the limit of the value shown for R in table 1 and when the difference be- tween the two values for the test sample does not exceed r, as calculated from the appropriate value of r given i
28、n table 1. When the difference exceeds the value of r, one or more additional tests shall be carried out in accord- ance with annex A, simultaneously with a corre- sponding blank test and an analysis of a certified reference material. When the analytical value obtained for the certified reference ma
29、terial is outside the limits of the value shown for R in table 1, an additional analysis shall be carried out simultaneously on one test sample and one certified reference material, with one blank test. The analytical value obtained for the certified reference material shall be examined for the ac-
30、ceptance of the value for the test sample, as above. If the value obtained for the certified reference ma- terial is again outside the limits, the procedure shall be repeated with a different reference material of the same type of ore until two acceptable values for the test sample are obtained. 8.2
31、.3 Calculation of final result The final result is the arithmetic mean of the ac- ceptable analytical values for the test sample or as otherwise determined by the operations specified in annex A, calculated to the fourth decimal place and rounded off to the second decimal place as follows: a) when t
32、he figure in the third decimal place is less than 5, it is discarded and the figure in the sec- ond decimal place is kept unchanged; b) when the figure in the third decimal place is 5 and there is a,figure other than 0 in the fourth decimal place, or when the figure in the third decimal place is gre
33、ater than 5, the figure in the second decimal place is increased by one; c) when the figure in the third decimal place is 5 and the figure 0 is in the fourth decimal place, the 5 is discarded and the figure in the second deci- mal place is kept unchanged if it is 0, 2, 4, 6 or 8 and increased by one
34、 if it is 1, 3, 5, 7 or 9. Table 1 - Precision data for iron determination Values in mass percentaae Sample Ore type Mean Fe,O, content Repeatability r Reproducibility R MT/l2115 - 1,778 0,119 6 0,571 8 MT/l 213 Gibbsite, boehmite, hematite 5,637 0,171 8 0,459 6 MT11214 Gibbsite, boehmite, hematite
35、12,893 0,337 3 0,666 a MT112113 Boehmite, hematite, chamosite 26,64 0,361 7 0,725 6 MTH2f2 Gibbsite, hematite, goethite 43,44 0,363 1 0,650 9 Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without l
36、icense from IHS-,-,-IS0 10213:1991E) 9 Test report The test report shall include the following infor- mation: a) details necessary for the identification of the sample: b) reference to this International Standard (includ- ing a reference to the method used); c) the result of the analysis; d) referen
37、ce number of the result; e) any characteristics noticed during the determi- nation and any operations not specified in this International Standard which may have had an influence on the results, either for the test sam- ple or the certified reference material(s). Copyright International Organization
38、 for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 10213:1991(E) Annex A (normative) Flowsheet of the procedure for the acceptance of test results xc Xl + x2 2 NO - 1 I Perform x3 I l- - NO Perform x3, x4
39、Perform x4 Range of x1, x2, x3, x4, 1,s r y= x1 + x2 + x3 + x4 4 -_-. r : as defined in 8.2.1, Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 10213:1991(E) Annex 8 (
40、informative) Graphical representation of precision data Coefficients (i) r=A+R(lnx) where ?-= repeatability A = 0,064 4 B = 0,066 6 x= % (m/m) of Fe203 Regression coefficient = 0,948 3 (ii) R = A + B(ln x) where R = reproducibility A = 0,490 3 B = 0,052 3 x= % (mlnr) of Fez03 Regression coefficient
41、= 0,647 1 Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 10213:1991(E) OJ I I I I ,I, 2 3 4 I I 5 678910 I I 20 30 40 50 Iron oxide content %(mlm) Finure B-1 8 Copyr
42、ight International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 10213:1991(E) UDC 553.492:543.242:546.72 Descriptors: minerals and ores, aluminlum ores, chemical analysis, determlnatlon of content, Iron, reduction methods, tltanlum chlorides. Price based on 8 pages Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
