Opta Waive
Opta Minerals Blast Cleaning Abrasives

Blackblast – Coal Slag

Blackblast is a blast-cleaning abrasive made of coal slag from coal-fired power plants.

This abrasive is considered to be one of the safest non-recyclable industrial blasting media, and is most commonly used for blasting of coated or uncoated metal and concrete surfaces.

Blackblast is widely used for the surface preparation of ships, water tanks, bridges, steel constructions, off-shore drilling rigs, rails cars, etc. Blackblast complies with the newest abrasive specifications and California Air Resource Board Standards.

Blackblast Coal Slag Photo

Advantages of Blackblast – Coal Slag

  • Fast cutting
  • Non-reactant – will not interfere with your coatings
  • Easy cleanup
  • Low free-crystalline silica, less than 0.1%


  • California Air Resource Board (CARB)
  • QPL Approved
  • Meets SSPC AB-1 Specification: Type II – Slag Abrasives,
    Class A - Crystalline silica less than or equal to 1.0%

Available Sizes and Profiles:

Size Profile Use
Utility #8-40 3.5 - 5.5 Mil For the tough blasting job
Medium #12-40 2.5 - 4.0 Mil For the tough blasting job
Medium Fine #20-40 2.0 - 3.5 Mil General blast cleaning
Fine #30-60 1.0 - 2.5 Mil General blast cleaning on delicate substrates when a smooth finish is required
Extra Fine #50-150 0.5 - 1.5 Mil When a very smooth finish is required

Technical Specifications

Symbol Name Percentage
SiO2 (Silicon Dioxide, Total) ~46.5%
Al2O2 (Aluminum Oxide) ~22.5%
Fe2O3 (Iron Oxide) ~19.0%
CaO (Calcium Oxide) ~5.5%
MgO (Magnesium Oxide) ~1.0%
TiO2 (Titanium Oxide) ~1.0%
SiO2 (Crystalline Silica) <0.1%
Loss on ignition (LOI) ~3.0%


Colour: Black
Bulk Density: 90 lb/ft3
Grain Shape: Angular
Solubility: Insoluble
Hardness: > 7 Mohs (see our hardness index)


  • 55 lb. paper bags, 56 bags/pallet
  • 3000 lb. Super Sacs
  • Bulk (blower truck or rail hopper cars)


Blackblast Canada
Blackblast USA

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