1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-22336-6 SANS 6072:2009 Edition 2SOUTH AFRICAN NATIONAL STANDARD Coking properties of coal (Ruhr dilatometer test) Published by SABS Standa
4、rds Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001 Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 6072:2009 Edition 2 Table of changes Change No. Date Sco
5、pe Foreword This South African standard was approved by National Committee SABS SC 27B, Solid mineral fuels Test methods, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was published in April 2009. This document supers
6、edes SABS SM 6072:1984 (edition 1). This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 6072:2009 Edition 2 1 Coking properties of coal (Ruhr dilatometer test) 1 Scope This standard specifies a method for the determination of the coking proper
7、ties of coal by using the Ruhr dilatometer. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any ame
8、ndments) applies. Information on currently valid national and international standards can be obtained from the SABS Standards Division. SANS 18283, Hard coal and coke Manual sampling. 3 Definitions 3.1 repeatability difference between the results of duplicate determinations, carried out at different
9、 times in the same laboratory by the same operator using the same furnace on the same laboratory sample 3.2 reproducibility difference between the means of the results of duplicate determinations, carried out by two different operators using different apparatus on test portions taken from the same g
10、ross sample following reduction to pass a test sieve of aperture size not exceeding 4,0 mm 4 Principle Coal passing a 150 m test sieve is formed under pressure into a pencil. The pencil of coal is inserted into a precisely calibrated narrow tube, topped by a calibrated steel rod (piston) which slide
11、s in the bore of the tube, and the whole is heated at a constant and precise rate. The displacement of the piston is automatically and continuously recorded as a function of the temperature, and a curve, of the type shown in figure 1, is produced from which the dilatometric parameters are determined
12、. NOTE 1 The Ruhr dilatometer test is a variation of the Audibert-Arnu dilatometer test described in ISO 349. If the apparatus used is not equipped with an automatic temperature controller and a device for the automatic registration of the curve, the recommendations of ISO 349 concerning equipment t
13、o be used for the accurate observation of dilatometer piston displacement, the measurement of temperature, control and adjustment of the heating rate, and the recording, calculation and plotting of results should be observed. NOTE 2 The principal factors that can influence the accuracy of the result
14、s are the following: a) Deterioration of the coal as a result of incorrect storage or faulty drying. b) Deviation from the tolerances of This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 6072:2009 Edition 2 2 1) the internal dimensions of th
15、e dilatometer tube, 2) the clearance between tube and piston, 3) the mass of the piston, and 4) the dimensions of the mould. c) Deviation from the specified mean rate and constancy of heating. d) Deviation from the recommendations for the preparation of the sample in respect of maximum particle size
16、, or for the preparation of the pencil. 5 Apparatus 5.1 Apparatus for preparing the coal pencil 5.1.1 Mould with accessories A mould made from steel (case-hardened after machining) and having a polished, uniformly tapered bore, with a tamping pin and a pencil gauge, essentially as shown in figure 2.
17、 Check the mould periodically during use, e.g. with a suitable, appropriately calibrated, tapered gauge or set of gauges inserted through the larger orifice of the mould, to ensure continued compliance with the dimensional requirements for the bore. Replace the mould if necessary. 5.1.2 Press, a scr
18、ew press with a pressure gauge having a range of 0 MPa to 1 000 MPa, as shown in figure 3. NOTE The commercial pressure gauge normally supplied with the apparatus is graduated in tonne, and has a range of 0 tonne to 3 tonne. 5.1.3 Mallet, with a plastics head, and that has a mass of approximately 20
19、0 g. 5.2 Dilatometer, as shown in figure 4, and consisting essentially of the following components: a) Electric furnace, consisting basically of a cylindrical block of aluminium bronze of approximate length and diameter 460 mm and 65 mm respectively, that is heated by a metallic winding that is suit
20、ably insulated, and that has at least three vertical holes of depth at least 380 mm and diameter 15 mm 0,1 mm. One of the holes is used for the measurement of the temperature of the furnace (see 5.2(b). The furnace is capable of providing a rate of heating of 3 C/min up to a temperature of 550 C. It
21、s calibration is such that, in respect of each hole used for holding a dilatometer tube (for actual dilatometric examination of a sample) and at a temperature of approximately 450 C, the temperature inside a dilatometer tube (placed in its normal position in a hole) at a position 30 mm above the int
22、ernal base of the tube (equivalent to the temperature registered by the calibrated temperature-measuring device in its normal position (see 5.2(b) and clause 6) and the temperature at any other position along its length differ by less than 1) 2 C in the lowest 120 mm of the tube, 2) 5 C in the regio
23、n 120 mm to 180 mm from the bottom of the tube, and 3) 10 C in the region 180 mm to 250 mm from the bottom of the tube. The furnace is equipped with a temperature controller of the automatic programmed type and such that, over a temperature range of 250 C to 550 C, a mean rate of temperature rise of
24、 3 C 0,05 C/min is maintained with a maximum variation of 1 C/30 C rise in any 10 min period. This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 6072:2009 Edition 2 3 NOTE If a dilatometer tube is no longer capable of being freely suspended f
25、rom its collar in an appropriate hole in the furnace block, the hole should be cleaned out. b) Temperature-measuring device, a suitable temperature sensor, connected to a recorder that is accurate to within 1 C, and that is so installed in a dilatometer tube placed in its normal position in the appr
26、opriate hole in the furnace block that the sensor tip is positioned centrally in the tube and 30 mm above the internal base of the tube. NOTE 1 If the temperature sensor is of the platinum resistance type, it should be of a design suitable for point measurement, and if it is of a thermocouple type,
27、it should comprise unsheathed thermocouple elements of diameter not exceeding 0,71 mm. NOTE 2 The accuracy of the temperature-measuring device should be confirmed, by direct potentiometric calibration against a standard EMF, at frequent (e.g. monthly) intervals to detect any possible malfunction of
28、the recorder or of the sensor, and the sensor should be replaced, if necessary. c) Dilatometer tubes and pistons 1) Tubes, straight, cold-drawn seamless tubes of heat-resistant steel, of external diameter 14,5 mm 0,1 mm and internal diameter 8,00 mm 0,05 mm, and each fitted with a gas-tight threaded
29、 plug at the base and a collar at the top. Each tube has a total length of 380 mm and is such that, when inserted in a hole in the furnace block, the tube is supported only by the collar, with the threaded plug clear of the bottom of the hole. NOTE After a tube has been used for 100 determinations,
30、inspect it for wear in accordance with the recommendations given in Annex A and, if the tube is still satisfactory, repeat the inspection after every subsequent 25 tests. 2) Pistons, made of steel rod, of diameter 7,80 mm 0,05 mm, and of suitable length. The mass of each piston is so adjusted, by ma
31、chining cut-out portions from the piston, that the combined mass of the piston and recording pen assembly (see 5.2(d) is 150 g 5 g. The difference between the diameter of the piston and the internal diameter of the tube in which the piston is used is 0,20 mm 0,05 mm when new, and may not exceed 0,27
32、5 mm in use. It is recommended that a stand be provided for the tubes and pistons to allow them to cool in a vertical position after removal from the furnace. d) System for recording piston movement Recording system that provides for the continuous recording of piston movement on a chart by means of
33、 pens clipped firmly to the tops of the pistons. The chart is affixed to a cylinder rotated uniformly by either a clockwork or a synchronous motor and mounted on a stand that is clamped to the top of the outer casing of the dilatometer. Two tests can be recorded simultaneously, and the cylinder diam
34、eter and speed of rotation are such that a range of 180 C occupies at least 150 mm. The vertical scale of the chart should be subdivided at 3 mm intervals, corresponding to 5 % contraction or expansion of the coal pencil, and the scale should be graduated in units of 50 % from -50 % to 300 %. This s
35、tandard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 6072:2009 Edition 2 4 5.3 Cleaning Only tubes and pistons that are scrupulously clean shall be used for a test. The following method of cleaning tubes and pistons that have been used previously is
36、recommended. To clean a tube remove the plug, crush the semi-coke and remove as much of it as possible with an auger of diameter approximately 7,8 mm. Complete the cleaning process with a reamer, consisting of a wear-resistant steel bar of semicircular section of diameter within the range 7,90 mm to
37、 7,95 mm. Ensure that no solids remain at the bottom or on the wall and, immediately before a test, clean finally with a wire brush of diameter slightly in excess of 8 mm and replace the plug. If desired, after using the auger, replace the plug and fill the tube with benzene or another appropriate o
38、rganic solvent and allow to soak for several hours. Then remove the plug and complete the cleaning process as above, using the reamer and the wire brush. A piston, including its base, should be cleaned with fine emery paper, taking care not to round the edges, and checking that the piston slides fre
39、ely in the tube. NOTE The total length of each of the cleaning implements should be approximately 400 mm. 6 Calibration of apparatus Place a dilatometer tube in each of the appropriate holes in the furnace and then, while maintaining a heating rate of 3 C/min and using a thermocouple with wires of d
40、iameter not exceeding 0,71 mm and with its thermo-junction in the centre of the tube 30 mm above its bottom, record the temperature readings, in each of the tubes in turn, at suitable intervals over the range 250 C to 550 C. Also record the corresponding temperature readings indicated by the tempera
41、ture-measuring device (see 5.2(b) placed in its normal position in the furnace, and correct these readings by the differences found in respect of each of the dilatometer tube holes. NOTE After the initial calibration, it is recommended that the apparatus be re-calibrated after every 200 tests or aft
42、er a period of use of three months, whichever occurs first. 7 Procedure 7.1 Preparation of the coal pencil 7.1.1 Prepare the coal pencil and carry out the dilatometric examination of the coal on the same day that the laboratory sample has been prepared. 7.1.2 Prepare the coal sample strictly in acco
43、rdance with the relevant method in SANS 18283. Moisten approximately 10 g of the coal sample with approximately 1 mL of water and mix well by hand-stirring for 2 min to 5 min. NOTE To assist removal of the pencil from the mould, it is recommended that a suitable amount (e.g. 0,5 g/L of water) of a w
44、etting agent be added to the water and, for the same reason, it is essential that the preparation of the pencil be carried out without interruption. 7.1.3 Place the mould, with its plug (covering the larger orifice) and base in position, on a firm surface. Place approximately 0,5 g of the moistened
45、coal (see 7.1.2) in the mould, place the tamping pin on top of the coal, and consolidate the sample by three or four sharp blows from the mallet. Repeat the process of filling and consolidating, using at least four further portions of the coal, until the mould has been filled. This standard may only
46、 be used and printed by approved subscription and freemailing clients of the SABS.SANS 6072:2009 Edition 2 5 7.1.4 After the last portion has been added and consolidated, place the mould on the load cell of the pressure gauge in the press, and further compress the coal pencil by applying a pressure
47、that is continuously increased until a reading of 520 MPa (equivalent to a reading of 1,5 tonne on commercial instruments see NOTE to 5.1.2) is registered, and then releasing the pressure immediately. NOTE Depending on the nature of the coal, it might be necessary to use a higher pressure, i.e. up t
48、o a maximum of 693 MPa (a reading of 2 tonnne on commercial instruments), to provide for a properly compressed coal pencil. 7.1.5 To remove the coal pencil from the mould, start by removing the base and the plug from the mould barrel. Trim the wide end of the pencil of irregularities by scraping the
49、 end of the pencil with a suitable metal straight-edge of an appropriate width for insertion into the recess at the bottom of the mould barrel. Then expel the coal pencil from the mould by suspending the mould on the carrier arm of the press and screwing the plunger down onto the smaller diametrical surface of the pencil. 7.1.6 Finally, so place the coal pencil in the pencil gauge that its thick end rests against the stop of the gauge, and adjust the length of the pencil to 60 mm 0,5 mm by cutting away as much as necessary of the protruding thin en
