Coal Tar Pitch Bitumen

Coal Tar Pitch (CTP) is a high-carbon, thermoplastic binding material obtained as the residual fraction during the high-temperature distillation of coal tar, a by-product of metallurgical coke production.

During distillation, lighter aromatic compounds are removed, leaving a dense, black, glossy, carbon-rich residue known as coal tar pitch.

Unlike petroleum bitumen, Coal Tar Pitch is aromatic-rich, carbon-intensive, and primarily used in metallurgical, refractory, and carbon industries.

Manufacturing & Refining Process

Coal Carbonization:
Coal heated to 900–1,200°C in coke ovens, producing metallurgical coke and coal tar vapors.

Coal Tar Recovery:
Tar vapors condensed into crude coal tar.

Fractional Distillation:
Light oils (benzene, toluene) removed → middle oils separated → final residue becomes coal tar pitch.

Pitch Modification (if required):
Softening point adjustment, quinoline insolubles (QI) control, and special processing for electrode or needle pitch.

Structural & Chemical Composition

Coal Tar Pitch primarily consists of:

Polycyclic Aromatic Hydrocarbons (PAHs)
High molecular weight aromatics
Free carbon and mesophase precursors

This structure provides excellent binding ability, high coking yield, and strong chemical and thermal resistance.

Key Technical Characteristics

High Carbon Content: Carbon yield of 40–60%, converting into solid carbon on heating
Exceptional Adhesion: Strong bonding with carbon, graphite, aggregates, and metals
Thermal Stability: Resists deformation at high temperatures
Chemical Resistance: Resistant to acids, alkalis, salts, and moisture
Thermoplastic Nature: Softens on heating and re-hardens on cooling
Thermal Shock Resistance: Withstands repeated heating and cooling cycles

Typical Mechanical & Physical Properties

Grade Classification of Coal Tar Pitch

Binder Grade Pitch: Used for aluminum anodes, carbon blocks, graphite electrodes
Impregnating Pitch: Low QI, used to fill pores in carbon materials
Needle Pitch: Premium grade for ultra-high-power graphite electrodes
Hard Pitch: High softening point for refractories and waterproofing
Liquid / Molten Pitch: Supplied hot for continuous industrial processes

Available Supply Forms

Solid pitch lumps
Briquettes or blocks
Molten pitch (tankers)
Customized grades for electrode and refractory industries

Applications

Aluminum Industry: Binder for carbon anodes in Hall-Héroult process
Graphite & Electrodes: Binder for petroleum coke and graphite
Refractories: Carbon bricks, tap-hole mass, furnace linings
Road & Flooring: Mastic asphalt, industrial pavements
Roofing & Waterproofing: Roofing felt and anti-corrosion coatings
Foundries & Steel: Mold coatings, carbon additives, furnace linings

Advantages of Coal Tar Pitch

Extremely high carbon yield
Superior binding and impregnation
Excellent chemical resistance
Performs reliably at extreme temperatures
Long industrial service life

Limitations & Safety Considerations

Contains PAHs – controlled handling required
Limited use in modern road surfacing due to regulations
Requires heating for application

Handling, Storage & Safety

Store in dry, shaded areas
Use appropriate PPE during handling
Follow environmental and occupational safety regulations

Standards & Testing References

ASTM D36 – Softening Point
ASTM D2416 – Coking Value
ISO pitch specifications
Industry-specific buyer standards

Coal Tar Pitch vs Petroleum Bitumen