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1、BRITISH STANDARD BS 622:1967 Incorporating Amendment No. 1 Specification for Potassium and sodium cyanides for electroplating Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 05:59:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 622:1967 This British Standard, having been approved by the Surf
2、ace Coatings (other than paint) Industry Standards Committee and endorsed by the Chairman of the Engineering Divisional Council, was published under the authority of the General Council on 26 May 1967 BSI 11-1999 First published July 1935 First revision April 1953 Second revision May 1967 The follow
3、ing BSI references relate to the work on this standard: Committee reference SRE/8 Draft for comment 66/9567 ISBN 0 580 00578 X Co-operating organizations The Surface Coatings (other than paints) Industry Standards Committee, under whose supervision this British Standard was prepared, consists of rep
4、resentatives from the following Government departments and scientific and industrial organizations: Aluminium Federation Assay Offices Committee of Great Britain Association of Metal Sprayers British Bolt, Nut, Screw and Rivet Federation British Cycle and Motor Cycle Industries Association Limited*
5、British Electrical and Allied Manufacturers Association British Iron and Steel Federation British Jewellers Association British Non-Ferrous Metals Research Association* Chemical Industries Association* Electricity Council, the Central Electricity Generating Board and the Area Boards in England and W
6、ales Electronic Engineering Association Engineering Equipment Users Association Greater London Council Institute of Metal Finishing* Institute of Sheet Metal Engineers Institute of Vitreous Enamellers Metal Finishing Association* Ministry of Defence, Army Department Ministry of Defence, Navy Departm
7、ent Ministry of Technology Society of Motor Manufacturers and Traders Limited* Tin Research Institute* Vitreous Enamel Development Council Zinc Development Association* The scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly r
8、epresented on the committee entrusted with the preparation of this British Standard: British Federation of Master Printers British Sulphate of Copper Association Chemical Society Institution of Chemical Engineers Royal Institute of Chemistry Scientific Instrument Manufacturers Association Society of
9、 Chemical Industry United Kingdom Cutlery and Silverware Manufacturers Association Individual firms Amendments issued since publication Amd. No.Date of issueComments 2709August 1978Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 05:59:14 GMT+00:00 2006, U
10、ncontrolled Copy, (c) BSI BS 622:1967 BSI 11-1999i Contents Page Co-operating organizationsInside front cover Forewordii 1General1 1.1Scope1 1.2Precautions1 2Potassium cyanide1 2.1Physical form and appearance1 2.2Chemical composition1 2.3Impurities1 2.4Containers1 2.5Sampling and size of sample1 3So
11、dium cyanide1 3.1Physical form and appearance1 3.2Chemical composition1 3.3Impurities1 3.4Containers1 3.5Sampling and size of sample1 Appendix A Sampling and sample preparation3 Appendix B Determination of cyanide3 Appendix C Determination of sodium in potassium cyanide3 Appendix D Determination of
12、sulphide4 Appendix E Determination of chloride5 Appendix F Determination of water insoluble matter5 Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 05:59:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 622:1967 ii BSI 11-1999 Foreword This standard makes reference to the following British St
13、andards: BS 612, Nessler cylinders. BS 1752, Laboratory sintered or fritted filters. BS 3978, Water for laboratory use. This British Standard is one of a series of standards that has been prepared to meet the requirements of electroplaters, others in the series being: BS 558 and BS 564, Nickel anode
14、s and nickel salts for electroplating. BS 1468, Tin anodes and tin salts for electroplating. BS 1561, Silver anodes and silver salts for electroplating. BS 2656, Zinc anodes, zinc cyanide and zinc oxide for electroplating. BS 2657, Fluoroboric acid and metallic fluoroborates for electroplating. BS 2
15、867, Copper sulphate for electroplating. BS 2868, Cadmium anodes and cadmium oxide for electroplating. BS 2884, Copper cyanide for electroplating. Wherever appropriate, British Standard laboratory glassware should be used in the methods of test. A British Standard does not purport to include all the
16、 necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance 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, pages i and ii,
17、pages 1 to 5 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 table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 05:59:14 GMT+00:00 2006, Uncontrolled Copy, (c)
18、 BSI BS 622:1967 BSI 11-19991 1 General 1.1 Scope This British Standard specifies requirements for potassium cyanide and sodium cyanide for electroplating. 1.2 Precautions Cyanides are highly poisonous and it is essential to ensure that they are never touched with unprotected hands and that gloves a
19、re worn during sampling operations. Attention is drawn to the cautionary note on cyanide poisoning (ref. SHW 385) published by the Health and Safety Executive and obtainable from HMSO. 2 Potassium cyanide 2.1 Physical form and appearance Potassium cyanide (frequently known as single salt 97/99 %) sh
20、all be in the form of powder or moulded pieces and shall correspond to the formula KCN. 2.2 Chemical composition The material shall contain not less than 97.0 % of cyanide calculated as KCN when determined by the method described in Appendix B. 2.3 Impurities The following impurities, if present, sh
21、all not exceed the limits given when the impurities are determined by the method described in the appropriate appendix. 2.4 Containers The material shall be supplied in airtight, resealable containers with an opening large enough to allow the contents to be easily removed. 2.5 Sampling and size of s
22、ample In the event of dispute and unless otherwise agreed, the manufacturer or the purchaser shall have the right to take a sample for analysis from each container. A representative sample of the material weighing not less than 250 g is necessary for the purpose of examination under this standard. I
23、t shall be taken by the procedure given in Appendix A. 3 Sodium cyanide 3.1 Physical form and appearance Sodium cyanide (frequently known as single salt KCN value 129/131 %) shall be in the form of powder, granules or moulded pieces and shall correspond to the formula NaCN. 3.2 Chemical composition
24、The material shall contain not less than 97.0 % of cyanide calculated as NaCN (or 128.9 % calculated as KCN) when determined by the method described in Appendix B. 3.3 Impurities The following impurities, if present, shall not exceed the limits given when the impurities are determined by the method
25、described in the appropriate appendix. 3.4 Containers The material shall be supplied in airtight, resealable containers with an opening large enough to allow the contents to be easily removed. 3.5 Sampling and size of sample In the event of dispute and unless otherwise agreed, the manufacturer or th
26、e purchaser shall have the right to take a sample for analysis from each container. A representative sample of the material weighing not less than 250 g is necessary for the purpose of examination under this standard. It shall be taken by the procedure given in Appendix A. NOTEThe British Standards
27、Institution is the owner of a registered certification trade mark. This is shown below, enclosed in the words “Approved to British Standard”. This mark can be used only by manufacturers licensed under the certification mark scheme operated by the BSI. The presence of this mark on or in relation to a
28、 product is an assurance that the goods have been produced to comply with the requirements of the British Standard under a system of supervision, control and testing operated during manufacture and including periodical inspection at the manufacturers works in accordance with the certification mark s
29、cheme of the BSI. Sodium calculated as Na1.0 %Appendix C Sulphide calculated as S0.001 %Appendix D Chloride calculated as Cl0.05 %Appendix E Water insoluble matter0.02 %Appendix F Sulphide calculated as S0.005 %Appendix D Chloride calculated as Cl0.05 %Appendix E Water insoluble matter0.01 %Appendix
30、 F Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 05:59:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 622:1967 2 BSI 11-1999 Further particulars of the terms of licence may be obtained from the Director, British Standards Institution, 2 Park Street, London, W.1. Licensed Copy: sheffieldun
31、 sheffieldun, na, Tue Dec 05 05:59:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 622:1967 BSI 11-19993 Appendix A Sampling and sample preparation Potassium and sodium cyanides are very hygroscopic and lose strength rapidly on exposure to the atmosphere due to hydrolysis. To minimize errors due to
32、 this, packages to be sampled should only be opened for the minimum time necessary to extract a sample and then resealed. All sampling equipment should be dry and preferably warmed to approximately 50 C. To sample powdered and granulated products, remove the lid from the container and tilt it. Weari
33、ng gloves, force a stainless steel sampling spear almost to the bottom of the container, withdraw it and transfer the contents to a dry 250 g glass or plastics screw-capped bottle. Repeat as necessary until the bottle is full, replace the cap and seal with adhesive tape. To sample moulded pieces, re
34、move the container lid, and wearing gloves, rapidly select sufficient pieces at random to provide a 250 g sample. Scoop away the top layers to give access to the product well inside the container. Place the selected pieces in a large dry screw-capped bottle and reseal the container. Wearing a face s
35、hield and gloves, rapidly crush the sample to pieces 3 mm or less in size with a warm dry steel mortar and pestle and fill a dry 250 g glass or plastics screw-capped bottle. Seal the cap with adhesive tape. Appendix B Determination of cyanide B.1 Apparatus Grade A volumetric glassware shall be used.
36、 B.2 Reagents All reagents shall be of a recognized analytical reagent quality, and distilled water1) shall be used whenever water is specified. Potassium iodide solution, 10 % w/v. Silver nitrate solution, 0.05N. Sodium hydroxide solution, 5 % w/v. B.3 Procedure Weigh accurately about 5 g of sample
37、 in a tared stoppered weighing bottle. Dissolve in water containing 10 ml of 5 % sodium hydroxide solution per litre, transfer to a 500 ml one-mark graduated flask, dilute to volume with the same water containing sodium hydroxide and mix. Using a suction bulb (not suction by mouth) pipette 25.0 ml o
38、f the solution into a 500 ml tall-form beaker containing 300 ml of water and 3 ml of 5 % sodium hydroxide solution. Add 2 ml of 10 % potassium iodide solution and titrate with 0.05N silver nitrate solution using constant stirring, a black back-ground and transverse illumination to the first faint pe
39、rmanent turbidity. Add the 0.05N silver nitrate solution dropwise as the end point approaches. Appendix C Determination of sodium in potassium cyanide C.1 Apparatus A flame photometer or flame spectrophotometer. C.2 Reagents All reagents shall be of a recognized analytical reagent quality, and disti
40、lled water1) shall be used whenever water is specified. Hydrochloric acid, 4 % w/v. Hydrogen cyanide detector papers. Dissolve about 20 mg each of copper ethylacetoacetate and “tetra base” (4,4-tetramethyldiaminodiphenylmethane) in 5 ml of chloroform. Prepare this solution fresh as required. Apply a
41、 drop of this solution to a strip of filter paper. 1) BS 3978, “Water for laboratory use”. Sodium cyanide per cent by weight Volume of 0.05N AgNO3ml()9.803 Weight of sample (g) - -= Potassium cyanide per cent by weight Volume of 0.05N AgNO3ml()13.02 Weight of sample (g) - -= Licensed Copy: sheffield
42、un sheffieldun, na, Tue Dec 05 05:59:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 622:1967 4 BSI 11-1999 Sodium standard solution (1 ml N 1 mg Na). Dissolve 2.543 g of dry sodium chloride in water. Add 50 ml of 4 % hydrochloric acid and dilute to 1 litre in a one-mark graduated flask. C.3 Proced
43、ure Dissolve 1.00 g of sample in 25 ml of water in a 250 ml beaker. Transfer to an efficient fume chamber and add 40 ml of 4 % hydrochloric acid. Boil until hydrogen cyanide can no longer be detected with detector paper (no blue coloration). Cool, add 25 ml of 4 % hydrochloric acid and dilute to 1 l
44、itre in a one-mark graduated flask. Obtain a reading on the flame photometer or spectrophotometer and read off the sodium content of the sample from the calibration graph. C.4 Calibration Prepare a series of standard sodium solutions containing 0, 5.0, 10.0 and 15.0 ml of standard sodium solution (1
45、 ml N 1 mg Na) and 50 ml of 4 % hydrochloric acid in one litre of solution. (These correspond to 0, 0.5, 1.0 and 1.5 % Na respectively for a 1 g sample.) Obtain a reading for each of these solutions using a flame photometer with a sodium filter or a flame spectrophotometer at 589 nm, adjusting the i
46、nstrument sensitivity to give approximately full scale deflection on the highest standard. Plot a graph of per cent Na against instrument reading. This should be linear and should pass through the origin. Appendix D Determination of sulphide D.1 Reagents All reagents shall be of a recognized analyti
47、cal reagent quality, and distilled water2) shall be used whenever water is specified. Alkaline lead acetate solution. Dissolve 1.7 g of lead acetate and 35 g of sodium hydroxide in water and dilute to 100 ml. Sodium sulphide solution A (1 ml N 0.1 mg S approx.). Dissolve 0.75 g of Na2S.9H2O in fresh
48、ly boiled and cooled water and dilute to 1 litre. Pipette 100.0 ml of this solution into a 250 ml conical flask containing 10.0 ml 0.1N iodine solution and 25.0 ml 0.1N hydrochloric acid. Back titrate with 0.1N sodium thiosulphate adding 1 % starch solution as indicator before the end point. Let the
49、 volume of 0.1N iodine solution absorbed be a ml. Sodium sulphide solution B (1 ml N 1 g S). Fill a burette with sodium sulphide solution A and measure 100/1.6a ml into a 1 litre one-mark graduated flask and dilute to volume with freshly boiled and cooled water. Prepare immediately before use. D.2 Procedure Into a series of 50 ml Nessler cylinders3) place