ISO 3393:1976 PDF

Overview

ISO 3393:1976 is an international standard specifying a gravimetric method to determine the moisture content of cryolite (both natural and artificial) and aluminium fluoride for industrial use. Developed by ISO Technical Committee ISO/TC 47 (Chemistry), this method provides a precise and standardized approach for laboratories to measure moisture through controlled drying and mass loss.

This standard is crucial for industries relying on cryolite and aluminium fluoride, ensuring product quality and conformity with industrial chemical specifications. The gravimetric moisture determination method supports accurate, reproducible results necessary for quality control, process optimization, and compliance with trade requirements.

Key Topics

• Scope and Application Applicable to both natural and artificial cryolite, as well as aluminium fluoride used industrially. It is designed for laboratory use to quantify moisture content in raw and processed chemical samples.

• Principle The method involves drying a test sample at 110 ± 5 °C for 2 hours in a controlled oven, followed by weighing to calculate moisture loss gravimetrically.

• Apparatus Required

  • Squat weighing bottle (~45 mm diameter) with lid
  • Electric oven with temperature control at 110 ± 5 °C
  • Desiccator to cool samples post-drying
  • Precision balance capable of measurements to 0.001 g

• Procedure

  1. Prepare a ~20 g test portion of the sample in the pre-dried weighing bottle.
  2. Weigh the sample with lid before drying.
  3. Dry in oven for 2 hours without sealing the bottle fully.
  4. Cool sample in a desiccator, then weigh again to determine moisture loss.

• Expression of Results Moisture content is calculated as the percentage loss in mass due to drying relative to the initial mass of the wet sample.

• Test Reporting Reports include method reference, moisture content result, any deviations, and additional observations during testing.

Applications

• Industrial Quality Control Ensures precise moisture quantification in cryolite and aluminium fluoride batches, preventing processing issues linked to excess water content.

• Raw Material Inspection Verifies the moisture specifications of raw cryolite and aluminium fluoride materials prior to use in metal production or chemical manufacturing.

• Laboratory Analysis Provides a reliable gravimetric method for chemical laboratories performing routine analysis or research on cryolite and fluoride compounds.

• Trade and Compliance Supports adherence to international trade standards by enabling consistent testing procedures recognized globally.

Related Standards

ISO 3393 complements other ISO standards related to cryolite and aluminium fluoride to establish comprehensive chemical testing regimes:

• Cryolite-Specific Standards

  • ISO 1619: Preparation and storage of cryolite test samples
  • ISO 1620: Silica content determination by spectrophotometric method
  • ISO 1693 & 1694: Fluorine and iron content analysis
  • ISO 2366 & 2367: Sodium and aluminium content measurement
  • ISO 3392: Electrometric water content determination

• Aluminium Fluoride Standards

  • ISO 2362 & 2368 & 2369: Determination of fluorine, iron, silica content
  • ISO 2925: Preparation and storage of aluminium fluoride samples
  • ISO 3392: Water content by electrometric method
  • ISO 4279 & 4280: Sodium and sulphate content determination

These standards provide comprehensive guidance on sample preparation, chemical analyses, and additional property determinations that complement moisture content testing as per ISO 3393.

Keywords: ISO 3393, cryolite moisture determination, aluminium fluoride moisture content, gravimetric method, industrial chemical analysis, cryolite testing, moisture content standard, ISO chemical standards, industrial cryolite quality control, moisture analysis procedure.