ISO 11126-4:2018

Overview

ISO 11126-4:2018 is an international standard that specifies the requirements for coal furnace slag abrasives used in non-metallic blast-cleaning processes, particularly for the preparation of steel substrates prior to the application of paints and related products. This standard covers the properties of coal furnace slag abrasives supplied in their "new" condition, defining essential parameters such as particle size distribution, apparent density, hardness, moisture content, conductivity of aqueous extract, and water-soluble chlorides.

Designed by ISO Technical Committee ISO/TC 35, this standard ensures the quality, consistency, and safety of coal furnace slag abrasives used in abrasive blast-cleaning. While primarily developed for steelwork preparation, the properties outlined can also apply to surface preparation of other materials using blast-cleaning techniques described in ISO 8504-2.

Key Topics

• Scope and Application
  Specifies the requirements applicable only to new coal furnace slag abrasives used in blast-cleaning processes. It excludes abrasives during or after use.

• Particle Size Distribution
  Defines the particle size ranges and distribution with maximum allowable oversize and undersize residues to ensure effective abrasive action and surface cleanliness.

• Physical and Chemical Properties

  • Apparent Density: Must be within 2.4 to 2.6 kg/dm³
  • Mohs Hardness: Minimum of 6, ensuring sufficient abrasion efficiency
  • Moisture Content: Maximum 0.2% mass fraction to prevent clumping and maintain blasting performance
  • Conductivity of Aqueous Extract: Maximum 250 μS/cm to limit soluble contaminants
  • Water-Soluble Chlorides: Maximum 0.0025% mass fraction for corrosion prevention

• Material Composition
  Coal furnace slag abrasives are vitreous amorphous materials predominantly composed of aluminium silicate, with free crystalline silica content restricted to under 1% to minimize health hazards.

• Designation and Marking
  Abrasives are identified by a standardized format including "Abrasive ISO 11126 N/CS" followed by particle shape and size range, ensuring consistent identification across suppliers and users.

• Testing and Sampling
  Utilizes test methods from ISO 11127 parts 1 through 7, covering sampling, particle size distribution, density, hardness, moisture, contaminant measurement, and chloride content verification.

Applications

ISO 11126-4:2018 coal furnace slag abrasives are widely used in:

• Surface Preparation of Steel Substrates
  Essential for removing rust, mill scale, old coatings, and contaminants from steel surfaces before painting, ensuring optimal paint adhesion and durability.

• Industrial Blast-Cleaning Processes
  Suitable for cleaning structural steel, ship hulls, bridges, and fabricated steel components in manufacturing and maintenance environments.

• Preparation of Non-Steel Materials
  Although designed for steel, the specified abrasive properties make it adaptable for use on other metallic and non-metallic surfaces requiring abrasive blast-cleaning.

• Corrosion Protection Coating Projects
  The strict limits on chlorides and moisture in the slag help prevent corrosion under protective coatings, especially in harsh or marine environments.

• Environmental and Safety Compliance
  By adhering to ISO 11126-4, organizations ensure they use abrasives that meet international health, safety, and quality standards, reducing environmental impact and worker exposure risks.

Related Standards

To fully comply with surface preparation best practices, ISO 11126-4:2018 should be used in conjunction with:

• ISO 11127 Series

  • Part 1: Sampling of non-metallic blast-cleaning abrasives
  • Part 2: Determination of particle size distribution
  • Part 3: Determination of apparent density
  • Part 4: Hardness assessment
  • Part 5: Moisture determination
  • Part 6: Measurement of water-soluble contaminants
  • Part 7: Determination of water-soluble chlorides

• ISO 8504-2: Surface Preparation Methods
  Details abrasive blast-cleaning techniques suitable for steel and other materials.

By integrating ISO 11126-4 with these complementary standards, users can ensure comprehensive control over abrasive quality and surface preparation processes critical to coating performance and longevity.

Keywords: ISO 11126-4, coal furnace slag abrasive, blast-cleaning abrasives, steel substrate preparation, abrasive blast-cleaning, particle size distribution, Mohs hardness, moisture content, water-soluble chlorides, non-metallic abrasives, surface preparation standard, ISO 11127 test methods, ISO 8504-2.