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    ASTM D6656 - 16(2021)

    Standard Test Method for Determination of Chromic Oxide in Wet Blue (Perchloric Acid Oxidation)

    Active Standard ASTM D6656 | Developed by Subcommittee: D31.02

    Book of Standards Volume: 15.04


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    Significance and Use

    5.1 The procedure described is specific for chromium in Wet Blue. Vanadium is the only common interfering element and is rarely present in quantity. The precision and accuracy of the methods are usually, at least, as good as the sampling of Wet Blue itself.

    5.2 The chromium content of Wet Blue is related to the degree of tannage obtained, and hence may be a matter for specification in the purchase of Wet Blue. The procedure described provides adequate accuracy for this purpose.

    1. Scope

    1.1 This test method covers the determination of chromic oxide in Wet Blue that has been partly or completely tanned with chromium compounds. In general, the samples will contain chromium content between 1 % and 5 % when calculated as chromic oxide expressed upon a dry basis otherwise referred to as moisture-free basis (mfb).

    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 test method does not apply to Wet White.

    1.4 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. See Section 9 for specific safety hazards.

    1.5 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 (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    D6658 Test Method for Volatile Matter (Moisture) of Wet Blue by Oven Drying

    D6659 Practice for Sampling and Preparation of Wet Blue and Wet White for Physical and Chemical Tests

    E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods

    E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals

    E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method


    ICS Code

    ICS Number Code 59.140.10 (Processes and auxiliary materials); 71.040.40 (Chemical analysis)

    UNSPSC Code

    UNSPSC Code 11162300(Leathers)


    Referencing This Standard
    Link Here
    Link to Active (This link will always route to the current Active version of the standard.)

    DOI: 10.1520/D6656-16R21

    Citation Format

    ASTM D6656-16(2021), Standard Test Method for Determination of Chromic Oxide in Wet Blue (Perchloric Acid Oxidation), ASTM International, West Conshohocken, PA, 2021, www.astm.org

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