1、BRITISH STANDARD BS 1748-8: 1960 Method for The determination of phosphorus in copper alloys (photometric method)BS1748-8:1960 This British Standard, having been approved by the Non-ferrousMetals Industry Standards Committee and endorsed by the Chairman oftheEngineering Divisional Council, was publi
2、shed undertheauthority of theGeneralCouncil on 20July1960 BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference NFE/-/2 Draft for comment CZ(NFE) 8591 ISBN 0 580 01819 9 Co-operating organizations The Non-ferrous Metals Industry Standards Committee, under
3、whose supervision this British Standard was prepared, consists of representatives from the following Government departments, and scientific and industrial organizations: Admiralty* Institution of Mechanical Engineers Aluminium Development Association (Automobile Division) Aluminium Industry Council
4、Institution of Mining and Metallurgy Association of Bronze and Brass Founders* Institution of Structural Engineers Association of Consulting Engineers, Lead Development Association Incorporated Lead Sheet and Pipe Manufacturers Association of Non-ferrous Metal Stockists Federation British Bronze and
5、 Brass Ingot Light Metal Founders Association Manufacturers Association* London Metal Exchange British Electrical and Allied Manufacturers Magnesium Industry Council Association Ministry of Aviation* British Non-ferrous Metals Federation National Brassfoundry Association British Non-ferrous Metals R
6、esearch Post Office Association* Royal Institute of British Architects Cable Makers Association Society of British Aircraft Constructors Copper Development Association Society of Motor Manufacturers and Traders Crown Agents for Oversea Governments and Limited Administrations Tin Research Institute H
7、igh Commission of India War Office High Conductivity Copper Association Zinc Development Association Institute of British Foundrymen Individual manufacturers Institute of Metals The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together
8、 with the following, were directly represented on the sub-committee entrusted with the preparation of this British Standard: D.S.I.R. Laboratory of the Government Individual firms Chemist Amendments issued since publication Amd. No. Date CommentsBS1748-8:1960 BSI 11-1999 i Contents Page Co-operating
9、 organizations Inside front cover Foreword ii Introduction 1 Apparatus 1 Solutions required 1 Sampling 1 Calibration 2 Procedure 2BS1748-8:1960 ii BSI 11-1999 Foreword This standard makes reference to the following British Standards: BS 1400, Copper alloy ingots and castings. BS 1499, Sampling non-f
10、errous metals. This method for the determination of phosphorus is one of a series of methods for the analysis of copper alloys, which will form a complete British Standard issued in several parts. The methods are intended primarily for the analysis of the copper alloys included in BS1400, “Copper al
11、loy ingots and castings”, and those being included in the series of schedules of wrought copper and copper alloys, BS2870 to BS2875, of which BS2871 has already been published, and the remainder are in course of preparation. The methods have been found to give reliable and reproducible results and,
12、while in some instances they may appear to be lengthy, it should be realized that they are put forward as referee methods to be used in cases of dispute. In the preparation of the calibration graphs an attempt has been made to define concentrations, but because these are linked with the particular i
13、nstrument used for determining optical density they should be used only as a guide. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itse
14、lf confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to3 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment t
15、able on the inside front cover.BS1748-8:1960 BSI 11-1999 1 Introduction a) Principle. The sample is dissolved in a mixture of nitric and hydrochloric acids, and phosphorus is converted into orthophosphoric acid. Phosphovanadomolybdic acid is subsequently formed and the yellow colour is measured phot
16、ometrically. b) Range. Up to1.20per cent phosphorus. c) Reproducibility. Experiments have been carried out independently by a number of analysts using the method recommended in this standard. The degree of reproducibility that can be expected is shown by the following analysis of the results obtaine
17、d: d) Application. The method is applicable to all types of copper alloys provided a suitable compensating solution is used when elements are present which would otherwise interfere in the optical density determination. The percentage of arsenic normally present in the specified alloys does not inte
18、rfere. Apparatus a) Grade A graduated glassware shall be used throughout. b) Any instrument suitable for measuring the optical density of the solution at a wave-length of435m may be used. If a filter photometer is used the filter combination should conform as closely as possible to the above wave-le
19、ngth. The following conditions have been found suitable: Ilford601 with ChanceH503. 4cm and1cm cells. Solutions required All reagents shall be of the highest purity obtainable, and distilled water shall be used throughout. Solutions shall be freshly prepared and, where necessary, filtered. Standard
20、potassium dihydrogen phosphate (1mlN 0.20mg of phosphorus). Dissolve0.8787g of potassium dihydrogen phosphate (previously dried at105 C) in about250ml of water. Add100ml of nitric acid(20percent v/v) and dilute to1litre in a graduated flask. Ammonium molybdate (10percent w/v). Dissolve100g of ammoni
21、um molybdate (NH 4 ) 6 Mo 7 O 24 4H 2 O) in about600ml of warm water, cool, and dilute to1litre. Filter through a fine textured paper immediately before using. Ammonium vanadate (0.25percent w/v). Dissolve2.5g of ammonium metavanadate in about500ml of hot water. Add20ml of nitric acid(50percent v/v)
22、, cool, and dilute to1litre. Hydrogen peroxide (3percent). Dilute10ml of hydrogen peroxide(100vol) to100ml. Store in a dark bottle in a cool place. Nitric acid (50percent v/v). Dilute50ml of nitric acid (sp. gr.1.42) to100ml. Nitric acid (20percent v/v). Dilute20ml of nitric acid (sp. gr.1.42) to100
23、ml. Nitric-hydrochloric acid mixture. To500ml of water add320ml of nitric acid (sp. gr.1.42) and120ml of hydrochloric acid (sp. gr.1.161.18). Cool and dilute to1litre. Sampling Recommended methods of obtaining a suitable sample for the analytical procedure given below are described in BS1499, “Sampl
24、ing non-ferrous metals”. Phosphorus content Standard deviation per cent Below 0.10 0.5 1.20 per cent 0.004 0.01 0.02BS1748-8:1960 2 BSI 11-1999 Calibration Weigh2.00g of pure copper (containing less than0.0002percent phosphorus) into each of a number of150ml beakers. Use a further beaker in each cas
25、e for a blank determination and proceed as described below. i) Preparation of Graphs 1a and 2a Add30ml of the nitric-hydrochloric acid mixture to each beaker, cover and heat gently until the copper has dissolved. Make additions of the standard potassium dihydrogen phosphate solution as indicated in
26、the table (Note1). Add1ml of hydrogen peroxide (3per cent) and boil gently for5minutes. Avoid vigorous or prolonged boiling, since excessive loss of acid will affect the subsequent colour development. Cool slightly and add10.0ml of ammonium vanadate solution(0.25per cent). Cool to room temperature a
27、nd add10.0ml of ammonium molybdate solution (10per cent). Transfer to a100ml graduated flask, dilute to the mark and mix well. Allow to stand for5minutes at20 1 C, then measure the optical densities using conditions as specified under “Apparatus” (seealso Note2). Use4cm cells for Graph1a and1cm cell
28、s for Graph2a. Use the blank solution in the compensating cell. ii) Preparation of Graphs 1b and 2b Add45ml of the nitric-hydrochloric acid mixture to each beaker, cover and heat gently until the copper has dissolved. Cool and dilute to100ml in a graduated flask. Transfer10.0ml of each solution (equ
29、ivalent to0.2g sample) separately to150ml beakers. Make additions of the standard potassium dihydrogen phosphate solution as indicated in the table (Note1). Add10ml of the nitric-hydrochloric acid mixture,1ml of hydrogen peroxide (3per cent) and continue as described under “Calibration (i)” above. U
30、se4cm cells for Graph1b and1cm cells for Graph2b. Use the blank solution in the compensating cell. In each case plot the values obtained against percentage phosphorus (based on the sample weights subsequently used) and prepare calibration graphs. Procedure i) Phosphorus content up to 0.12 per cent D
31、issolve two separate2.000g weighings of the sample in30ml (Note1) of nitric-hydrochloric acid mixture. Mark the solutions “(T)” and “(C)”. At the same time, dissolve two separate2.00g weighings of pure copper in30ml of nitric-hydrochloric acid mixture. Mark the solutions “Blank (T)” and “Blank (C)”.
32、 Proceed with each as described under “Calibration”, but omit the addition of ammonium molybdate solution (10per cent) to solutions (C) and Blank(C). Measure the optical densities using the conditions as specified under “Apparatus” (Note2), using the solution (C) in the compensating cell. Deduct the
33、 blank reading and obtain the percentage phosphorus in the sample by reference to the appropriate calibration graph. ii) Phosphorus content 0.10 to1.20 per cent Dissolve2.000g of the sample in45ml (Note1) of the nitric-hydrochloric acid mixture. At the same time, dissolve2.000g of pure copper in45ml
34、 of the nitric-hydrochloric acid mixture to provide a blank. Boil each solution for1minute to remove nitrous fumes, cool and dilute each to100ml in graduated flasks. Graph Phosphorus content Cell size Volume of standard phosphate solution Sample weight subsequently used 1 (a) (b) 2 (a) (b) per cent
35、Up to0.03 0.100.30 0.020.12 0.201.20 cm 4 1 ml 0.51.02.03.04.0 2.04.06.08.010.012.015.0 g 2 0.2 2 0.2BS1748-8:1960 BSI 11-1999 3 Transfer two separate10ml aliquots of the sample solution (equivalent to0.20g sample) to150ml beakers and mark the solutions “(T)” and “(C)”. Transfer two separate10ml ali
36、quots of the blank solution to150ml beakers and mark the solutions “Blank (T)” and “Blank (C)”. Add to each solution10ml of the nitric-hydrochloric acid mixture, then1ml of hydrogen peroxide(3per cent). Proceed with each as described under “Calibration”, but omit the addition of ammonium molybdate s
37、olution (10per cent) to solutions (C) and Blank (C). Measure the optical densities using the conditions as specified under “Apparatus” (Note2), using the solution (C) in the compensating cell. Deduct the blank reading and obtain the percentage phosphorus in the sample by reference to the appropriate
38、 calibration graph. NOTE 1These recommended volumes should be found suitable, using the type of instrument referred to under “Apparatus”. Preparation of these graphs will depend on the type of instrument used to determine optical density and it may therefore be necessary to reduce these volumes, the
39、 weight of copper and the weight of sample subsequently used. The excess of nitro-hydrochloric acid mixture, however, must be maintained throughout. NOTE 2In the examination of sample solutions optical densities should preferably be between0.15and0.85, although this range may be extended slightly in
40、 the preparation of calibration graphs.BS1748-8: 1960 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorpor
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