ISO 3262-7:2023

Overview

ISO 3262-7:2023 is an international standard specifying the requirements and test methods for dolomite used as an extender. Dolomite, a natural calcium magnesium carbonate mineral, serves as a crucial raw material in various industrial applications, especially coatings, paints, and construction materials. This second edition updates the 1998 version to incorporate revised test methods and normative references, providing a clear framework for quality assurance and consistency in dolomite products worldwide.

Key Topics

• Scope: Defines specifications and corresponding test methods specifically for dolomite used as an extender.
• Dolomite Definition: Natural calcium magnesium carbonate with a specific chemical composition ratio between CaCO₃ and MgCO₃.
• Essential Requirements:
  • Calcium magnesium carbonate content (CaMg(CO₃)₂) with grade-specific minimum mass fractions.
  • Matter volatile at 105 °C.
  • Loss on ignition percentage.
  • Matter insoluble in hydrochloric acid and soluble in water limits.
  • pH range of aqueous suspensions.
• Conditional Requirements:
  • Residue on 45 µm sieve.
  • Particle size distribution analyzed by laser diffraction.
  • Colour and lightness to be agreed upon by stakeholders.
  • Resistivity of aqueous extracts.
• Sampling and Test Reporting:
  • Guidelines based on ISO 15528 for representative sampling.
  • Detailed test reports including product identification, test methods, compliance statements, and observations.

Applications

ISO 3262-7:2023 is essential for manufacturers, suppliers, and quality control specialists working with dolomite-based extenders. Its practical applications include:

• Paints and Coatings Industry: Ensuring consistent extender quality enhances pigment dispersion and coating durability.
• Construction Materials: Provides standards to confirm filler properties and compositional uniformity, influencing concrete and plaster performance.
• Plastics and Rubber Industry: Used as a mineral filler, dolomite adhering to this standard optimizes mechanical properties.
• Quality Assurance Labs: Utilize the prescribed test methods for verifying dolomite quality, particle size, chemical composition, and other critical attributes.

Implementing ISO 3262-7 supports product integrity, regulatory compliance, and international trade by harmonizing testing and specification criteria.

Related Standards

This part of ISO 3262 is part of a broader series addressing extenders and their testing methods:

• ISO 3262-1: Introduction and general test methods for extenders.
• ISO 787 Series: General methods of test for pigments and extenders, including determination of volatile matter, matter soluble in water, residue on sieve, pH value, and resistivity.
• ISO 8130-13: Particle size analysis by laser diffraction for coating powders, referenced here for dolomite particle size.
• ISO 15528: Guidelines for sampling paints, varnishes, and raw materials, critical for obtaining representative dolomite samples.
• ISO 18451-1: Terminology related to pigments, dyestuffs, and extenders, ensuring consistent vocabulary.

For additional information and other parts in the ISO 3262 series, visit the ISO website at www.iso.org.

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