1、BRITISH STANDARD BS 6092-12: 1981 Methods of Sampling and test for sodium and potassium silicates for industrial use Part 12: Limit test for sulphate content of sodium metasilicate NOTEIt is recommended that this Part be read in conjunction with the information in the “General introduction” publishe
2、d separately as BS 6092-0. UDC 661.683/.684:546.32284 + 546.33284:543.061:546.226BS6092-12:1981 This British Standard, having been prepared under the directionof the Chemicals Standards Committee, was published under the authorityofthe Executive Board and comes into effect on 27February1981 BSI 12-1
3、999 The following BSI references relate to the work on this standard: Committee reference CIC/22 Draft for comment 73/55424 DC ISBN 0 580 12049 X A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct ap
4、plication. 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, pages 1 and 2, an inside back cover and a back cover. This standard has been updated (see copyright
5、date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date of issue CommentsBS6092-12:1981 BSI 12-1999 i Contents Page 1 Scope 1 2 References 1 3 Principle 1 4 Reagents 1 5 Apparatus 1 6 P
6、rocedure 1 7 Expression of results 1 Publications referred to Inside back coverii blankBS6092-12:1981 BSI 12-1999 1 1 Scope This Part of BS6092describes a limit test for determining the compliance with the sulphate limit specified in BS3984for the Services grade of this material. NOTEThis limit is e
7、quivalent to a sulphate content, expressed as a percentage by mass of sodium sulphate (Na 2 SO 4 ), of 0.21. There is no International Standard corresponding to this Part of BS 6092. 2 References The titles of the publications referred to in this standard are listed on the inside back cover. 3 Princ
8、iple The turbidity produced by reacting a solution of the test portion with barium chloride solution is compared visually with that similarly produced by a standard sulphate solution. 4 Reagents The following reagents are required and shall be of recognized analytical quality. Water complying with t
9、he requirements of BS3978shall be used throughout. 4.1 Dimethylformamide. WARNING. Toxic and irritant. Avoid breathing vapour. Avoid contact with skin and eyes. 4.2 Hydrochloric acid, approximately5N solution. 4.3 Barium sulphate reagent. Mix15ml of0.5M barium chloride solution,55ml of water, and20m
10、l of sulphate-free ethanol 95% (V/V). Add5ml of a0.181g/l solution of potassium sulphate; dilute to100ml with water and mix thoroughly. Prepare this reagent freshly for each series of tests. 4.4 Standard sulphate solution. Dilute2.8ml of0.1N sulphuric acid solution to1000ml with water and mix thorou
11、ghly. 5 Apparatus Ordinary laboratory apparatus and the following are required. Matched Nessler cylinders, 50 ml capacity complying with the requirements of BS612. 6 Procedure 6.1 Test portion. Weigh, to the nearest0.01g,1g of the sample. 6.2 Test. Dissolve the test portion (6.1) in about25ml of wat
12、er, heating if necessary to complete the dissolution. Cool the solution to room temperature. Add5ml of the dimethylformamide(4.1) followed by8ml of the hydrochloric acid solution (4.2) and mix. A clear solution should be obtained. Transfer the solution quantitatively to a100ml one-mark volumetric fl
13、ask, dilute to the mark with water, and mix thoroughly. Transfer25ml of this solution to one of the Nessler cylinders. Transfer25ml of the standard sulphate solution(4.4) to the second Nessler cylinder and add2ml of the hydrochloric acid solution (4.2). To each cylinder add15ml of water and5ml of th
14、e barium sulphate reagent (4.3) and dilute to50ml with water. Stir both solutions thoroughly with glass rods, and allow them to stand for5min. Compare the turbidities produced in the two cylinders. 7 Expression of results Report whether or not the turbidity produced in the sample solution exceeds th
15、at produced in the standard sulphate solution.2 blankBS6092-12:1981 BSI 12-1999 Publications referred to BS 612, Nessler cylinders. BS 3978, Water for laboratory use. BS 6092-12: 1981 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body respons
16、ible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the latest amendments
17、 or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which can be found on
18、 the inside front cover. Tel:02089969000. Fax:02089967400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards. Buying standards Orders for all BSI, international and foreign standards publications should
19、 be addressed to Customer Services. Tel:02089969001. Fax:02089967001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as BritishStandards, unless otherwise requested. Information on standards BSI provides a wide r
20、ange of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information services are also available which give details on all its products and services. Contact the Information Centre. Tel:02089967111.
21、Fax:02089967048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details of these and other benefits contact Membership Administration. Tel:02089967002. Fax:02089967001. Copyright Copyright subsists
22、in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bodies. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any mea
23、ns electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel:02089967070.
