1、BRITISH STANDARD BS3907-7: 1969 Method for The determination of nickel in magnesium alloys (Photometric method) Methods for the analysis of magnesium and magnesium alloysBS3907-7:1969 This BritishStandard, having been approved by the Non-ferrous Metals Industry Standards Committee, was published und
2、er the authority ofthe Executive Board on 28February 1969 BSI 12-1999 The following BSI references relate to the work on this standard: Committee references NFE/23 andNFE/23/4 Draft for comment67/19251 ISBN 0 580 00483 X Co-operating organizations The Non-ferrous Metals Industry Standards Committee,
3、 under whose supervision this BritishStandard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Aluminium Federation Institution of Mining and Metallurgy Association of Bronze and Brass Founders Institution of Production
4、Engineers Association of Consulting Engineers Institution of Structural Engineers Board of Trade Lead Development Association British Bronze and Brass Ingot Manufacturers Light Metal Founders Association Association London Metal Exchange British Electrical and Allied Manufacturers Magnesium Industry
5、 Council* Association Ministry of Defence, Army Department* British Lead Manufacturers Association Ministry of Defence, Navy Department British Non-ferrous Metals Federation National Brassfoundry Association British Non-ferrous Metals Federations Non-ferrous Metal Stockists* High Conductivity Copper
6、 Group Post Office British Non-ferrous Metals Research Royal Institute of British Architects Association* Society of British Aerospace Companies Ltd. Copper Development Association Society of Motor Manufacturers and Crown Agents for Oversea Governments and Traders Ltd.* Administrations Tin Research
7、Institute Electric Cable Makers Confederation Zinc Development Association Institute of British Foundrymen Individual manufacturer Institute of Metals Institution of Mechanical Engineers (Automobile Division) The Government department and scientific and industrial organizations marked with an asteri
8、sk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this BritishStandard: Institute of Sheet Metal Engineering Individual analysts Ministry of Technology Ministry of Technology, Laboratory of the Government Chemist Amendment
9、s issued since publication Amd. No. Date CommentsBS3907-7:1969 BSI 12-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Introduction 1 2 Apparatus 1 3 Solutions required 1 4 Sampling 1 5 Procedure 1 6 Calibration 2 7 Calculation 2BS3907-7:1969 ii BSI 12-1999 Foreword T
10、his standard makes reference to the following BritishStandard: BS1499, Sampling non-ferrous metals. This method for the photometric determination of nickel in magnesium alloys is the seventh of a series which will form a complete BritishStandard under the collective title “Methods for the analysis o
11、f magnesium and magnesium alloys”, each being published as a separate part. Other methods in the series are as follows: Part 1: Aluminium in magnesium alloys (gravimetric method); Part 2: Iron in magnesium and magnesium alloys (photometric1:10phenanthroline method); Part 3: Copper in magnesium and m
12、agnesium alloys (photometric method); Part 4: Manganese in magnesium and magnesium alloys (photometric periodate method); Part 5: Manganese in magnesium and magnesium alloys (photometric periodate method) (low contents); Part 6: Zirconium in magnesium and magnesium alloys (photometric method); Part
13、8: Total rare earths in magnesium alloys (gravimetric method) 1) ; Part 9: Zinc in magnesium alloys (ion-exchange volumetric EDTA method) 1) ; Part 10: Manganese in magnesium alloys containing zirconium, rare earths or thorium (photometric method) 1) . The preparation of this series of methods has b
14、een authorized by the Non-ferrous Metals Industry Standards Committee as part of a general programme for the standardization of methods for the sampling and analysis of non-ferrous metals. The methods have been found to give reliable and reproducible results and, while in some instances they may app
15、ear to be lengthy, it should be appreciated that they are primarily intended as “referee” methods to be used in cases of dispute. 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. Compl
16、iance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 and2 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorpor
17、ated. This will be indicated in the amendment table on the inside front cover. 1) In course preparationBS3907-7:1969 BSI 12-1999 1 1 Introduction 1.1 Principle. The alloy is dissolved in acid, the dimethylglyoxime complex of the nickel is formed in ammoniacal citrate solution and the complex is extr
18、acted with chloroform. The nickel complex is then extracted from the chloroform with dilute hydrochloric acid and, after addition of bromine water, the solution is made ammoniacal and dimethylglyoxime added. The optical density of this solution is then measured at445nm. 1.2 Range. The method is reco
19、mmended for nickel contents between0001% and0.02%. 1.3 Reproducibility. Experiments have been carried out independently by a number of analysts using this method. The degree of reproducibility that can be expected is shown by the following analysis of the results obtained: 2 Apparatus 2.1 Class A vo
20、lumetric glassware complying with the appropriate BritishStandards shall be used throughout. 2.2 Any instrument suitable for measuring the optical density of the solution at a wave-length of445nm may be used with a2cm cell. Alternatively when a filter photometer of the balanced two-cell type is used
21、, the following conditions have been found suitable: Mercury vapour lamp. Ilford601 filter or equivalent filter. 2cm cells. 3 Solutions required All reagents shall be of the highest purity obtainable, and either distilled or demineralized water complying with BS3978 2)shall be used throughout. Solut
22、ions shall be freshly prepared and where necessary filtered. Standard nickel (1mlN 0.02mg of nickel). Dissolve13.460g of ammonium nickel sulphate (NH 4 ) 2 SO 4 NiSO 4 .6H 2 O in water, transfer to a1litre volumetric flask and dilute to the mark and mix. Transfer10ml of this solution to a1litre volu
23、metric flask, dilute to the mark and mix. Alternatively: Dissolve1.0g of high purity nickel in20ml of nitric acid(50%, transfer to a1litre volumetric flask, dilute to the mark and mix. Transfer20.0ml of this solution to a1litre volumetric flask, dilute to the mark and mix. Bromine water (saturated).
24、 To100ml of water add5ml of bromine, shake and allow to stand until saturated (preferably overnight). Citric acid (30% w/v). Dissolve300g of citric acid (C 6 H 8 O 7 .H 2 O) in water, dilute to1litre and mix. Dimethylglyoxime (1% w/v alcoholic). Dissolve10g of dimethylglyoxime in nearly1litre of war
25、m ethanol. Cool, dilute to1litre with ethanol and mix. Hydrochloric acid (5% v/v). Dilute50ml of hydrochloric acid (sp. gr.1.161.18) to1litre and mix. Hydrochloric-nitric acid. To100ml of water add75ml of hydrochloric acid (sp. gr.1.161.18), mix, add25ml of nitric acid (sp. gr.1.42) and mix. This re
26、agent should be prepared immediately before use. Nitric acid (50% v/v). Dilute500ml of nitric acid (sp. gr.1.42) to1litre and mix. Sulphurous acid. Pass sulphur dioxide gas into1litre of water until a saturated solution is obtained. Thiourea (10% w/v). Dissolve100g of thiourea in water, dilute to1li
27、tre and mix. Bromothymol blue (0.1% w/v). Dissolve0.1g of bromothymol blue in5ml of ethanol, dilute to100ml with water and mix. 4 Sampling Recommended methods of obtaining a suitable sample for the analytical procedure given below are described in BS1499, “Sampling non-ferrous metals”. 5 Procedure 5
28、.1 Adjust the weight of sample to be used as follows: Nickel content Standard deviation % 0.004 0.009 % 0.0002 0.0006 2) BS3978. Water for laboratory use. Nickel content Weight of sample over up to and including % 0.001 0.010 % 0.010 0.020 g 1.0 0.5BS3907-7:1969 2 BSI 12-1999 5.2 Carry out simultane
29、ously a blank determination following the same procedure and using the same amounts of reagents as with the sample. 5.3 Transfer the appropriate weight of sample to a250ml beaker fitted with a cover and add cautiously20ml of hydrochloric-nitric acid. When the reaction is complete, wash down the cove
30、r and side of the beaker and boil gently for23minutes. Allow to cool. 5.4 Add2ml of sulphurous acid,20ml of citric acid solution(30%),10ml of thiourea solution (10% and a few drops of bromothymol blue indicator(0.1%). Add ammonia solution (sp. gr.0.880.91) dropwise until the colour of the indicator
31、changes from yellow to blue and then add0.5ml in excess. Add2ml of dimethylglyoxime solution(1%alcoholic) and transfer to a100ml separating funnel. 5.5 Extract with10ml of chloroform, shaking for30seconds, allow the layers to separate and transfer the lower (organic) layer to a second separating fun
32、nel. Repeat the extraction with5ml of chloroform, again shaking for30seconds. After separation of the layers, combine the two organic extracts and discard the aqueous layer. 5.6 Extract the combined chloroform solutions twice with hydrochloric acid(5%), each time using10ml and shaking for one minute
33、. Combine the two acid extracts in a50ml volumetric flask. Add2ml of bromine water (saturated), allow to stand for15minutes, then add ammonia solution (sp. gr.0.880.91) until the solution is decolorized and add2ml in excess. Cool to below30 C, add2ml of dimethylglyoxime solution (1% alcoholic), dilu
34、te to volume and mix. 5.7 Allow the solution to stand for10minutes, then measure the optical density within the next30minutes using the conditions specified under “Apparatus”. 6 Calibration 6.1 Into a series of150ml beakers transfer varying amounts of standard nickel solution(1mlN 0.02mg of nickel)
35、to cover the range of00.10mg of nickel. Continue from5.4 of the procedure. 6.2 Deduct the blank on the reagents from the gross optical densities and prepare a calibration graph by plotting the net values against the nominal nickel contents of the solution. 7 Calculation Convert the optical density r
36、eading for the test sample corrected for blank to percentage nickel by means of the calibration graph.blankBS3907-7: 1969 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view o
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