ASTM D1506-23

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D1506 − 15 (Reapproved 2020) D1506 − 23
Standard Test Methods for
Carbon Black—Ash Content
This standard is issued under the fixed designation D1506; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 These test methods cover the determination of the ash content of carbon black.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. For specific precautionary statements see Sections 6 and 13.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D1799 Practice for Carbon Black—Sampling Packaged Shipments
D1900 Practice for Carbon Black—Sampling Bulk Shipments
D4483 Practice for Evaluating Precision for Test Method Standards in the Rubber and Carbon Black Manufacturing Industries
3. Summary of Test Method
3.1 A pre-dried sample (1 h at 125°C) is weighed before and after combustion for 16 h at 550°C. The remaining ash is weighed
and calculated as a percent of the dried sample.
4. Significance and Use
4.1 The ash content of a carbon black is the amount of non-carbon components present after combustion. Primary contributants
to ash are the manufacturing process water and the catalyst in the feedstock.
These test methods are under the jurisdiction of ASTM Committee D24 on Carbon Black and are the direct responsibility of Subcommittee D24.31 on Non-Carbon Black
Components of Carbon Black.
Current edition approved Nov. 1, 2020May 1, 2023. Published December 2020May 2023. Originally approved in 1957. Last previous edition approved in 20152020 as
D1506 – 15.D1506 – 15 (2020). DOI: 10.1520/D1506-15R20.10.1520/D1506-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1506 − 23
Method A—Muffle Furnace Method
5. Apparatus
5.1 Muffle Furnace, capable of temperature regulation of 625°C at 550°C. 550°C, including capability of air exchange.
5.2 Crucibles:
5.2.1 Porcelain Crucible, high-form, size O, rim 35 mm, height 29 mm, capacity 15 cm , with cover size E.
5.2.2 Porous Quartz Fiber Crucible, 20, 50, and 100 mL with optional disk inserts and lids.
5.3 Analytical Balance, having a sensitivity of 0.1 mg.
5.4 Desiccator.
5.5 Oven, gravity-convection type, capable of temperature regulation within 61°C at 125°C and temperature uniformity within
65°C.
6. Hazards
6.1 Precautions:
6.1.1 Keep the door of the furnace open about 6 mm to admit air Open, if available, adjustable air inlets – for example, integrated
in the door – to ensure a continuous stream of air passing through the furnace to support the combustion of organic
material.combustion.
6.1.2 Exert care in removing ashed sample from furnace to desiccator.
6.1.3 Always keep the cover on the crucible when transferring it to and from the desiccator to prevent the loss of ash due to air
currents.
6.1.4 After the sample has cooled in the desiccator, admit air slowly to avoid loss of ash from the crucible.
7. Sampling
7.1 Samples shall be taken in accordance with Practices D1799 or D1900.
8. Procedure
8.1 Porous quartz fiber crucibles and optional disks should be ignited in the furnace at 550 6 25°C for at least 15 min. Porcelain
crucibles should be ignited with cover in the muffle furnace at 550 6 25°C for 1 h. Place the crucible and cover in the desiccator.
Cool to room temperature and weigh to nearest 0.1 mg.
8.2 Dry an adequate sample of carbon black for 1 h in the gravity-convection oven set at 125°C in an open container of suitable
dimensions, so that the depth of the black is no more than 10 mm. Cool and store the sample in a desiccator.
8.3 Weigh 2 6 0.1 g of the dried carbon black into the ignited crucible and weigh to the nearest 0.1 mg. Place the uncovered
crucible and its cover into the furnace (Note 1) at 550°C for 16 h (porcelain crucible) or 1.5 h (porous quartz fiber crucible—see
6.1.1). Cover the crucible containing the ash, remove from the furnace to the desiccator, and allow to cool to room temperature.
The sole source of supply of the apparatus (quartz ashing dishes, Part Number 303040) known to the committee at this time is CEM Corporation, P.O. Box 200, Matthews,
NC 28106. If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration
at a meeting of the responsible technical committee, which you may attend.
D1506 − 23
Weigh the covered crucible to the nearest 0.1 mg. Put the covered crucible back into the furnace for additional 0.5 h. Reweigh to
the nearest 0.1 mg. Repeat this weighing process until constant mass is obtained.
NOTE 1—For carbon blacks with very low ash content (such as high purity blacks) larger sample mass and longer ashing time may be required.
NOTE 2—If control testing is done at temperatures exceeding 550°C, some volatile salts may be lost from inorganic ash.
9. Calculation
9.1 Calculate the percent ash to the nearest 0.01 % as follows:
A 5 @~D 2 B!/~C 2 B!# ×100 (1)
where:
A = ash, %,
B = mass of crucible, g,
C = mass of crucible plus the sample, g, and
D = mass of crucible plus the ash, g.
10. Report
10.1 Report the following information:
10.1.1 Proper identification of the sample, and
10.1.2 A result obtained from an individual determination reported to the nearest 0.01 %.
11. Precision and Bias
11.1 These precision statements have been prepared in accordance with Practice D4483. Refer to this practice for terminology and
other statistical details.
11.2 The precision results in this precision and bias section give an estimate of the precision of this test method with the materials
used in the particular interlaboratory program described below. The precision parameters should not be used for acceptance or
rejection testing of any group of materials without documentation that they are applicable to those particular materials and the
specific testing protocols of the test method. Any appropriate value may be used from Table 1.
11.3 A type 1 inter-laboratory precision program was conducted as detailed in Table 2. Both repeatability and reproducibility
represent short term (daily) testing conditions. The testing was performed using two operators in each laboratory performing the
test once on each of two days (total of four tests). A test result is the value obtained from a single determination. Acceptable
difference values were not measured. The between operator component of variation is included in the calculated values for r and
R.
11.4 The results of the precision calculations for this test are given in Table 1. The materials are arranged in ascending “mean
level” order.
TABLE 1 Precision Parameters for D1506 Ash Content, (Type 1
Precision)
Units Percent Ash
Material Mean Level Sr (r) SR (R)
IRB#6 (N330) 0.233 0.018 21.4 0.027 32.4
SRB D5 (N762) 0.258 0.015 16.0 0.030 32.6
N650 0.289 0.019 18.7 0.031 30.4
N550 0.436 0.025 16.1 0.037 23.7
SRB A5 (N135) 0.565 0.023 11.5 0.056 27.9
Average 0.356
Pooled Values 0.020 16.0 0.037 29.7
D1506 − 23
TABLE 2 Interlaboratory Precision Program
Nominal Test Period Material Number of Laboratories
March 1996 N650 45
October 1996 IRB#6 (N330) 37
March 1997 SRB N762 48
September 1997 SRB A5 (N135) 43
March 1998 N550 46
11.5 Repeatability—The pooled relative repeatability, (r), of this test has been established as 16.0 %. Any other value in Table 1
may be used as an estimate of repeatability, as appropriate. The difference between two single test results (or determinations) found
on identical test material under the repeatability conditions prescribed for this test will exceed the repeatability on an average of
not more than once in 20 cases in the norma
...