Zinc – Special High Grade (SHG)

Special High Grade (SHG) Zinc is the highest commercially traded purity grade of primary zinc metal, with a minimum zinc content of 99.995%. It is produced almost exclusively through electrolytic refining, ensuring exceptionally low impurity levels and high chemical consistency.

SHG zinc is the global benchmark grade used where strict quality control, superior corrosion performance, and precise alloying behavior are required

Strengthening & Metallurgical Behavior

Metallurgical Structure

Pure zinc exhibits a hexagonal close-packed (HCP) crystal lattice

Limited slip systems → low room-temperature ductility

High ductility at 100–150°C

Strengthening Behavior

Cannot be heat-treated

No precipitation hardening capability

Strength improvement possible only by:

Grain refinement
Minor cold working (limited)
Alloying with Al, Cu, Mg (most common route)

Key Characteristics of SHG Zinc

1. Ultra-High Purity

Minimal tramp elements
Stable electrochemical behavior
Superior coating and alloy performance

2. Excellent Corrosion Resistance

Forms protective ZnO/ZnCO₃ layer
Highly effective sacrificial protection

3. Superior Alloying Performance

Predictable reactions during melting
No contamination of final alloys

4. Low Melting Temperature

Reduced energy consumption
High casting efficiency

Refining & Processing Properties

Refining Process

Zinc ore roasting
Acid leaching
Electrolytic purification
Cathode melting
Controlled casting into ingots

Processing Advantages

Uniform melting behavior
Low dross formation
Excellent fluidity in molten state
Ideal for continuous and batch furnaces

Available Forms

Standard ingots (20–25 kg)
Jumbo ingots (500–1,000 kg)
Slabs
Bars
Pigs
Custom cast shapes
Laboratory-grade ingots

Applications of SHG Zinc

1. Galvanizing Industry

Hot-dip galvanizing baths
Continuous galvanizing lines
Zinc-aluminum-magnesium coatings

2. Alloy Manufacturing

ZAMAK alloys
Brass (Cu–Zn)
ZA alloys
Zinc-magnesium alloys

3. Chemical Industry

Zinc oxide (high-purity grades)
Zinc salts
Pigments and catalysts

4. Battery & Energy Sector

Alkaline batteries
Zinc-carbon batteries
Zinc-air batteries

5. Metallurgical Processing

Cementation
Precious metal recovery
Controlled reduction reactions

Advantages of SHG Zinc

✔ Highest commercially available zinc purity
✔ Superior corrosion and coating performance
✔ Consistent alloy chemistry
✔ Low impurity-related defects
✔ Fully recyclable
✔ Global acceptance and standardization

Limitations

❌ Low mechanical strength
❌ Not suitable for load-bearing structures
❌ Brittle at room temperature
❌ Requires alloying for structural applications

Why Choose Special High Grade Zinc?

SHG zinc is selected when process stability, surface quality, and product reliability are non-negotiable.

Choose SHG Zinc when you need:

Defect-free galvanizing coatings
Controlled alloy compositions
High-purity chemical feedstock
Long-term corrosion protection
Compliance with international standards

Standards & Specifications

ASTM B6 – SHG Zinc
ISO 752
EN 1179
LME SHG Zinc Contract
IS 209: Zinc Ingots (India)

Special High Grade (SHG) Zinc is the gold standard of primary zinc metal, offering unmatched purity, predictable metallurgy, and superior industrial performance. It forms the backbone of galvanizing, alloy manufacturing, chemical processing, and energy storage industries worldwide.