1、BRITISH STANDARD BS 4493:1969 Specification for Copper salts for electroplating UDC 621.357.7:661.856BS4493:1969 This British Standard, having been approved by the Surface Coatings (other than Paints) Industry Standards Committee, was published under the authorityof the General Councilon 29September
2、1969 BSI 12-1999 BS 2867 first published September1957 BS 2884 first published August1957 Combination and first revision September1969 The following BSI references relate to the work on this standard: Committee reference SRE/8 Draft for comment 66/9566 ISBN 580 05582 5 Co-operating organizations The
3、 Surface Coatings (other than Paints) Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Assay Offices Committee of Great Britain Association of M
4、etal Sprayers British Bolt, Nut, Screw and Rivet Federation British Cycle and Motor Cycle Industries Association Limited* British Electrical and Allied Manufacturers Association British Jewellers Association British Non-Ferrous Metals Research Association* British Steel Industry Chemical Industries
5、Association* Electricity Council, the Central Electricity Generating Board and the Area Boards in England and Wales Electronic Engineering Association Engineering Equipment Users Association Greater London Council Institute of Metal Finishing* Institute of Sheet Metal Engineers* Institute of Vitreou
6、s Enamellers* Metal Finishing Association* Ministry of Defence, Army Department Ministry of Defence, Navy Department Ministry of Technology Society of Motor Manufacturers and Traders Limited* Tin Research Institute* Vitreous Enamel Development Council Zinc Development Association* The scientific and
7、 industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: British Sulphate of Copper Association Institution of Chemical Engineers Royal Institute of Chemistry
8、Scientific Instrument Manufacturers Association Society of Chemical Industry United Kingdom Cutlery and Silverware Manufacturers Association Individual firms Amendments issued since publication Amd. No. Date of issue CommentsBS4493:1969 BSI 12-1999 i Contents Page Co-operating organizations Inside f
9、ront cover Foreword ii 1 General 1 2 Copper sulphate 1 3 Copper cyanide 1 4 Copper pyrophosphate 2 Appendix A Determination of copper in copper cyanide and copper sulphate 3 Appendix B Determination of iron in copper cyanide and copper sulphate 4 Appendix C Determination of arsenic in copper sulphat
10、e and copper pyrophosphate 4 Appendix D Determination of insoluble matter in copper salts 7 Appendix E Determination of chloride in copper cyanide and copper sulphate 8 Appendix F Determination of cyanide in copper cyanide 9 Appendix G Determination of copper in copper pyrophosphate 11 Appendix H De
11、termination of pyrophosphate in copper pyrophosphate 11 Figure 1 Apparatus for arsenic determination 6 Figure 2 Apparatus for the determination of cyanide 10 Table 1 Limits of impurities in copper sulphate 1 Table 2 Limits of impurities in copper cyanide 1 Table 3 Limits of impurities in copper pyro
12、phosphate 2BS4493:1969 ii BSI 12-1999 Foreword This standard makes reference to the following British Standards: 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 o
13、f electroplaters, others in the series being: BS 558, BS 564, Nickel anodes and nickel salts for electroplating. BS 622, Potassium and sodium cyanides for electroplating. BS 1468, Tin anodes and tin salts for electroplating. BS 1561, Silver anodes and silver salts for electroplating. BS 2656, Zinc a
14、nodes, zinc cyanide and zinc oxide for electroplating. BS 2657, Fluoroboric acid and metallic fluoroborates for electroplating. BS 2868, Cadmium anodes and cadmium oxide for electroplating. This standard contains in revised form what was previously covered by the separate standards BS2867, “Copper s
15、ulphate for electroplating” and BS2884, “Copper cyanide for electroplating”, with the addition of requirements for copper pyrophosphate. By this combination the new standard fits more logically into the existing series of standards, BS2867 and BS2884 having been withdrawn. A British Standard does no
16、t 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 itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside f
17、ront cover, pages i and ii, pages1 to 12, an inside back cover 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.BS4493:1969 BSI 12-1999 1 1 General 1.1 Scope This Br
18、itish Standard specifies requirements for copper sulphate, copper cyanide and copper pyrophosphate for electroplating. 1.2 Precautions Copper cyanide is extremely poisonous and must only be handled in accordance with the instructions given in Form385 published by the Factory Department of the Depart
19、ment of Employment and Productivity and obtainable from Her Majestys Stationery Office. This form should be displayed wherever copper cyanide is stored or handled. 1.3 Reagents and apparatus All reagents shall be of a recognized analytical reagent quality and distilled water 1)shall be used wherever
20、 water is specified. Wherever appropriate, British Standard laboratory glassware should be used in the methods of test. 2 Copper sulphate 2.1 Physical form and appearance Copper sulphate shall be in a crystalline or finely granulated form and shall correspond approximately in composition to CuSO 4 .
21、5H 2 O. 2.2 Chemical composition The material shall contain not less than24.9% of copper when determined by the method described inAppendix A. 2.3 Impurities Impurities, if present, shall not exceed the limits given inTable 1 when determined by the method described in the appropriate appendix. Table
22、 1 Limits of impurities in copper sulphate 2.4 Sampling and size of sample A representative sample of the material weighing not less than 1kg is necessary for the purpose of examination under this British Standard. The sample shall be taken from freshly opened packages and shall be packed in a clean
23、, dry, airtight bottle and sealed. The sample shall be rapidly crushed if necessary, well mixed, and returned to the bottle. 3 Copper cyanide 3.1 Physical form and appearance Copper cyanide shall be in the form of a cream-coloured powder and shall correspond approximately in composition to CuCN. 3.2
24、 Chemical composition The material shall contain not less than69.0% copper calculated as metal and not less than27.5% cyanide calculated as CN when determined by the methods described inAppendix A andAppendix F respectively. 3.3 Impurities Impurities, if present, shall not exceed the limits given in
25、Table 2 when determined by the method described in the appropriate appendix. Table 2 Limits of impurities in copper cyanide 3.4 Sampling and size of sample A representative sample of the material weighing not less than 250g is necessary for the purpose of examination under this British Standard. The
26、 sample shall be taken from fleshly opened packages and shall be packed in a clean, dry, airtight bottle and sealed. 1) BS 3978, “Water for laboratory use”. Impurity Per cent (max.) Appendix Iron, calculated as Fe 0.075 B Arsenic, calculated as As 0.0015 C Insoluble matter 0.1 D Chlorides, calculate
27、d as Cl 0.02 E Impurity Per cent (max.) Appendix Iron, calculated as Fe 0.05 B Insoluble matter 0.15 D Chloride, calculated as Cl 0.4 EBS4493:1969 2 BSI 12-1999 4 Copper pyrophosphate 4.1 Physical form and appearance Copper pyrophosphate shall be in the form of a free-flowing light blue powder. The
28、degree of hydration is a slightly variable quantity but the formula should roughly correspond to Cu 2 P 2 O 7 .5H 2 O. 4.2 Chemical composition The material shall contain not less than32.5% copper and 44.5% pyrophosphate calculated as P 2 O 7when determined by the methods described inAppendix G andA
29、ppendix H respectively. 4.3 Impurities Impurities, if present, shall not exceed the limits given inTable 3, when determined by the method described in the appropriate appendix. Table 3 Limits of impurities in copper pyrophosphate 4.4 Sampling and size of sample A representative sample of the materia
30、l weighing not less than 250g is necessary for the purpose of examination under this British Standard. The sample shall be taken from freshly opened packages and shall be packed in a clean dry airtight bottle and sealed. Impurity Per cent (max.) Appendix Arsenic, calculated as As 0.0025 C Insoluble
31、matter 0.1 DBS4493:1969 BSI 12-1999 3 Appendix A Determination of copper in copper cyanide and copper sulphate A.1 Reagents The following reagents are required: Nitric acid, d = 1.42. Nitric acid, d = 1.20. Sodium sulphide solution, 10% w/v Na 2 S.9H 2 O. Prepare freshly as required. Sulphuric acid,
32、 50% v/v. Acetone. Hydrogen cyanide detector papers. Dissolve about20mg each of copper ethylacetoacetate and tetra base (4,4-tetramethyldiaminodiphenylmethane) in 5ml of chloroform. Prepare as required. Apply a drop of this solution to a strip of filter paper. A.2 Apparatus The following apparatus i
33、s required: Electrodeposition apparatus with magnetic stirrer or rotating platinum gauze cathode. A.3 Preparation of sample solution A.3.1 Copper cyanide. Weigh accurately about1g of the sample and transfer to a250ml squat beaker with50ml of water. Transfer to an efficient fume chamber. Cautiously a
34、dd5ml of nitric acid (d = 1.42), cover the beaker with a watch glass and boil until all hydrogen cyanide is expelled. (Detector paper not turned blue in vapour from beaker.) Rinse the watch glass and sides of the beaker with water, add5ml of sulphuric acid (50% v/v) and evaporate to a volume of 25ml
35、. Cool and dilute to200ml with water. Complete the determination according toA.4. A.3.2 Copper sulphate. Weigh accurately about5g of the sample as rapidly as possible and transfer to a250ml squat beaker with50ml of water. Add5ml of sulphuric acid (50% v/v) and5ml of nitric acid (d = 1.42), swirl unt
36、il the sample has dissolved and evaporate to a volume of25ml. Cool and dilute to200ml with water. Complete the determination according toA.4. A.4 Procedure Transfer the beaker to the electrodeposition apparatus, fit the tared cathode and cover with a split watch glass. Electrolyse using a current of
37、 2.5A to 3A with a rotating cathode or a magnetic stirrer until the solution is colourless. Rinse the watch glass and inner walls of the beaker with water and continue the electrolysis for a further10min. When electrolysis is complete (see Note1) rinse the electrodes and without interrupting the cur
38、rent wash the cathode with a fine stream of water, collecting the rinsings in the sample beaker. Retain the electrolyte for the determination of iron (Appendix B). Switch off the current, remove the cathode, rinse it with water and twice with acetone. Dry at105 C and reweigh (see Note2). NOTE 1Confi
39、rm complete deposition of copper by mixing one drop of electrolyte with one drop of sodium sulphide solution (10% w/v) on a white tile. A black precipitate of copper sulphide indicates incomplete electrolysis. NOTE 2After use strip the deposit from the cathode by immersing in nitric acid (d = 1.20).
40、 Percentage of copper Increase in mass of cathode (g) Mass of sample taken (g) -100 . =BS4493:1969 4 BSI 12-1999 Appendix B Determination of iron in copper cyanide and copper sulphate B.1 Reagents The following reagents are required: Ammonium hydroxide, 35% w/w (d = 0.88). Thioglycollic acid, 50% v/
41、v. Standard iron solution (1ml N 0.00001gFe). Dissolve7.0g of ammonium ferrous sulphate, FeSO 4 (NH 4 ) 2 .SO 4 .6H 2 O, in50ml of sulphuric acid (10% v/v). Add4g of ammonium persulphate and boil for5min. Cool and dilute to1 litre. Dilute 10.0ml of this solution to1 litre with water as required. B.2
42、 Apparatus Any instrument suitable for measuring the optical density of the solution at a wavelength of530nm may be used. B.3 Procedure Boil the solution retained fromAppendix A after removal of copper for15min, cool to room temperature and dilute with water to250ml in a one-mark volumetric flask. P
43、ipette an aliquot of the sample solution containing not more than50g of iron into a25ml one-mark volumetric flask and develop the colour as described for the preparation of the calibration graph. Measure the optical density of the sample in a4cm cell at530nm against a distilled water reference. Corr
44、ect the optical density for the blank and refer the corrected value to the calibration graph. B.4 Calibration Into a series of25ml one-mark volumetric flasks transfer aliquots of standard iron solution corresponding to20,40,60,80 and100g of iron. To each flask add0.2ml thioglycollic acid and neutral
45、ize by the dropwise addition of ammonium hydroxide (d = 0.88) until a pink coloration just appears and add5drops in excess. Cool to room temperature, dilute to the mark with water and mix. Prepare a reagent blank omitting the standard iron solution and adding5 drops of ammonium hydroxide. Measure th
46、e optical density of the standard and blank solutions in4cm cells at a wavelength of530nm using distilled water in the reference cell. Deduct the optical density of the blank solution from the values obtained for the standard solutions and plot the corrected values against mass of iron (g). Appendix
47、 C Determination of arsenic in copper sulphate and copper pyrophosphate C.1 Reagents The following reagents are required: Hydrochloric acid, d = 1.161.18. Stannous chloride solution. Dissolve40g of stannous chloride dihydrate in a mixture of25ml of water and75ml of hydrochloric acid. Iodine solution
48、, 0.1N, prepared by dissolving 1.27g of iodine and2g of potassium iodide crystals in100ml of water. Potassium iodide solution, 150g/l. Store in the dark. Silver diethyldithiocarbamate solution, 5g/l in pyridine. Dissolve1g of silver diethyldithiocarbamate in pyridine (d = 0.98 approx.) and dilute to
49、200ml with this pyridine. Store in a well-stoppered glass bottle protected from light. This solution is stable for about2 months. Percentage iron as Fe Mass of iron (g ) 0.025 Vol. of aliquot (ml)mass of sample taken Appendix A (g) - in - =BS4493:1969 BSI 12-1999 5 Using good quality commercial silver diethyldithiocarbamate 2)
