ISO 3262-6:2022

Overview

ISO 3262-6:2022 is an internationally recognized standard that specifies the requirements and test methods for precipitated calcium carbonate (PCC) used as an extender in various industrial applications. This second edition standard, developed by ISO Technical Committee ISO/TC 256 in collaboration with the European Committee for Standardization (CEN/TC 298), updates and replaces the 1998 version to reflect current industry practices and testing methodologies.

The document establishes essential quality parameters, standardized sampling methods, and detailed laboratory test procedures to ensure consistent performance of precipitated calcium carbonate products. This includes physical and chemical properties vital for product evaluation and quality control.

Key Topics

• Scope and Definitions: ISO 3262-6 defines precipitated calcium carbonate as synthetic calcium carbonate crystals, either trigonal like calcite or rhombic bipyramidal like aragonite, with or without surface modification.

• Essential Requirements: The standard sets critical criteria such as:

  • Minimum calcium carbonate content (≥ 90% mass fraction)
  • Maximum residue retained on a 45 µm sieve (0.1%)
  • Maximum matter volatile at 105 °C (1.0%)
  • Maximum loss on ignition (up to 50%, as agreed)
  • Limits on matter soluble in water (0.2%)
  • pH range of aqueous suspension (7 to 11)
  • Matter insoluble in hydrochloric acid (≤ 0.2%)

• Sampling: Guidance adheres to ISO 15528 to ensure representative sample collection, maintaining test accuracy and reliability.

• Test Methods for Matter Insoluble in Hydrochloric Acid: Two methods are detailed:

  • Oven Method: Involves acid digestion, filtration through a membrane filter, drying in an air oven, and gravimetric analysis.
  • Furnace Method: Suitable for surface-modified PCC, involving acid digestion, filtration with quantitative filter paper, ignition in a furnace at 900 °C, and gravimetric measurement.

• Additional Parameters: Conditional requirements include particle size distribution, color, lightness, and resistivity of aqueous extracts, with test methods specified or to be agreed upon by parties involved.

• Test Reporting: The standard emphasizes comprehensive reporting to document product identification, test results, compliance status, test deviations, anomalies, and testing dates.

Applications

Precipitated calcium carbonate specified under ISO 3262-6 is widely used as an extender and pigment in industries such as:

• Paints and coatings: Enhances whiteness, opacity, and durability.
• Plastics and rubber manufacturing: Improves mechanical properties and reduces production costs.
• Paper production: Acts as a filler to enhance brightness and surface smoothness.
• Adhesives and sealants: Optimizes viscosity and stability.
• Pharmaceutical and food industries: Applicable in controlled forms for inert filler or calcium supplementation.

The standard’s rigorous test methods ensure the PCC's performance meets industrial demands, supporting quality control, regulatory compliance, and supplier qualification across global markets.

Related Standards

ISO 3262-6 references and complements several other ISO standards that are essential for comprehensive quality assessment of calcium carbonate extenders:

• ISO 3262-1: General introduction and test methods applicable to extenders.
• ISO 787 series: Various general test methods for pigments and extenders, including determination of volatile matter, solubility, pH, resistivity, residue on sieve, and colorimetric analysis.
• ISO 15528: Sampling guidelines critical for accurate testing.
• ISO 3696: Specifies the quality of water used in laboratory analyses.

Together, these standards form a cohesive framework for testing, specification, and handling of precipitated calcium carbonate to guarantee reliability and consistency in industrial applications.

Keywords: ISO 3262-6:2022, precipitated calcium carbonate, PCC, extenders, test methods, calcium carbonate specifications, quality control, industrial pigments, sampling methods, chemical analysis, hydrochloric acid insoluble matter, paint additives, plastic fillers, paper fillers.