ISO 1619:1976

Overview

ISO 1619:1976 - Cryolite, Natural and Artificial - Preparation and Storage of Test Samples specifies standardized procedures for preparing and storing test samples of both natural and artificial cryolite. This international standard applies to materials with a molar ratio of sodium fluoride (NaF) to aluminum trifluoride (AlF₃) between 3 and 1.7, encompassing a range of crude and synthetic cryolite samples. The standard is essential for ensuring the reliability and consistency of laboratory samples before physical, physico-chemical, and chemical tests.

Ensuring uniform sample preparation and storage directly improves the accuracy of subsequent analytical methods and helps laboratories, manufacturers, and quality control personnel maintain high-quality processes.

Key Topics

• Sample Types: Describes the preparation of both crude and dried samples of cryolite, addressing each step to ensure representative and consistent test materials.
• Sample Preparation:
  • Laboratory samples are initially prepared following referenced ISO sampling methods.
  • Crude samples are used for determining geometric characteristics, moisture content, and specific physical or physico-chemical properties.
  • Dried samples are primarily prepared for chemical analysis, including elemental determination.
• Grinding and Sieving:
  • All material is ground and passed through a 0.125 mm mesh sieve to achieve uniform particle size.
  • Sieving is repeated until all particles meet mesh requirements.
• Drying Conditions:
  • Dried samples are conditioned by heating at approximately 110°C to remove moisture, then cooled in a desiccator.
• Sample Storage:
  • Prepared samples are stored in airtight containers that are nearly filled to minimize contamination and moisture change.
  • Containers are required to be clearly labeled with the product name, origin, sample type, sieve details, and date of preparation.

Applications

ISO 1619:1976 is widely used in the following contexts:

• Quality Control: Used by chemical and metallurgical industries for quality assurance in cryolite production and processing.
• Analytical Laboratories: Laboratories performing physical, chemical, and physico-chemical analysis benefit from consistent methods for preparing cryolite samples, ensuring comparability and repeatability of test results.
• Materials Characterization: Researchers and analysts utilize the standard for accurate measurement of geometric properties, moisture, and composition in both natural and artificial cryolite.
• Regulatory Compliance: Helps organizations meet international and industry-specific regulatory requirements for the handling and analysis of cryolite.

Having a standardized procedure for sample preparation and storage also supports traceability and robust documentation, critical for audit trails and certification processes.

Related Standards

Several other ISO standards complement ISO 1619:1976, providing analytical methods for determining specific properties and impurities in cryolite:

• ISO 1620 - Determination of silica content in cryolite (Modified Willard-Winter method)
• ISO 1693 - Determination of fluorine content
• ISO 1694 - Determination of iron content (1,10-Phenanthroline photometric method)
• ISO 2366 & ISO 2367 - Determination of sodium and aluminum content (flame emission/atomic absorption and gravimetric methods)
• ISO 3391-3393 - Methods for determining calcium, water, and moisture content
• ISO 4277 & ISO 4280 - Evaluation of free fluorides and sulphate content

Organizations implementing ISO 1619:1976 often integrate these related standards to provide a comprehensive quality and analytical framework for cryolite materials.

By conforming to ISO 1619:1976 for cryolite sample preparation and storage, organizations ensure reliable analytical results, maintain regulatory compliance, and enhance the consistency and reproducibility of laboratory data.