Basicity is a ratio. In any chromic salt solution, the electrovalence of the chromium (+3) is satisfied by the hydroxyl ions and by acid ions. The extent to which this electravalence is satisfied by the hydroxyl ions, expressed as a percentage, is the basicity. The basicity of a chrome tanning liquid is closely related to the tanning behavior of the solution.

1. Scope

1.1 This practice is intended to show how the results of the chromium analysis (Test Method D3898) and the acidity determination (Test Method D3913) can be combined to permit calculation of the basicity of a chrome tanning liquor.

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 and health practices and determine the applicability of regulatory limitations prior to use.

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

D3898 Test Method for Chromic Oxide in Basic Chromium Tanning Liquors

D3913 Test Method for Acidity in Basic Chromium Tanning Liquors

Keywords

basicity; chrome tanning liquor; Schorlemmer; Acidity, alkalinity, pH--leather; Chrome-tanning materials; Tanning liquors

ICS Code

ICS Number Code 59.140.10 (Processes and auxiliary materials)

Citing ASTM Standards

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