The procedure described is specific for chromium in wet blue. Vanadium is the only common interfering element and this is rarely present in quantity. The precision and accuracy of the methods are usually at least as good as the sampling of the wet blue itself, and the accuracy of previously performed test methods.

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 %, calculated as chromic oxide expressed upon a dry basis otherwise referred to as moisture-free basis (mfb).

1.2 This test method is specific in that it applies to a sample or samples that are the resultant ash following the execution of Test Method D6716.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

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 and health practices and determine the applicability of regulatory limitations prior to use. Specific hazards are given in Section 8.

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 for Physical and Chemical Tests

D6716 Test Method for Total Ash in Wet Blue or Wet White

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

Keywords

ash; blue stock; chrome content; chromic oxide; perchloric acid oxidation; wet blue; Blue stock (leather); Chrome complex content; Chromic oxide; Ash--leather; Perchloric acid oxidation; Wet blue ;

ICS Code

ICS Number Code 77.120.40 (Nickel, chromium and their alloys)

Citing ASTM Standards

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