Overview

Direct Smelting of Antimony Ingot from Ore

United Metals is a prominent leader in the production of antimony ingots, employing cutting-edge smelting technology to extract high-purity antimony from both antimony ore and antimony sulfide. With operational bases in India and Zimbabwe, we utilise efficient and sustainable metallurgical processes that deliver superior-grade antimony to meet the demands of global industries.

Antimony (Sb) is a vital metalloid characterised by its high hardness, exceptional corrosion resistance, and capacity to improve the properties of various metals. Our direct smelting approach enhances recovery rates while prioritising environmental responsibility — establishing United Metals as a trusted supplier in the international market.

Antimony is now classified as a critical mineral by the United States, European Union, and United Kingdom — making secure, reliable supply a strategic priority for manufacturers worldwide.

Melting Point
630.5
°C
Density
6.68
g / cm³
Min. Purity
99.65%
Sb — Standard Grade
Ingot Form
Silver-grey
Standard cast ingots
Unit Weight
25 kg
± 5% per ingot
Origins
ZW · IN
Zimbabwe & India
Methodology

Smelting & Refining Process

United Metals' direct smelting route converts high-grade stibnite ore into refined antimony ingot through a precise three-stage metallurgical process — each stage purpose-built for maximum recovery and purity.

01
Feed Preparation
Ore Selection & Preparation
High-grade stibnite (Sb₂S₃) ores are selectively sourced from leading mining sites in Zimbabwe and India. Ore is characterised by geological survey, sorted by Sb grade, crushed to liberation size, and pre-concentrated before entering the smelting circuit. Only ores meeting minimum feed grade thresholds are accepted.
Feed: Stibnite ore · Avg 25% Sb · Pre-crushed
02
Primary Smelting
Volatilisation Roasting & Reverberatory Furnace
Stibnite is subjected to volatilisation roasting — controlled oxidation drives off sulfur and volatilises antimony as Sb₂O₃ fumes, which are captured and condensed. The residue is then processed in reverberatory furnaces at 900–1,000°C, reducing the oxide to crude antimony metal and producing antimony trioxide (Sb₂O₃) as a marketable by-product.
Output: Crude antimony metal + Sb₂O₃ by-product
03
High-Purity Refining
Chlorination Refining & Casting
Crude antimony undergoes chlorination refining in graphite-lined reactors — antimony trichloride (SbCl₃) is formed, purified by distillation, then reduced back to high-purity metal. This technique selectively removes arsenic, lead, and other trace impurities to achieve 99.65–99.85% Sb purity. The refined melt is cast into standard 25 kg silver-grey ingots and rigorously tested before despatch.
Final product: 99.65–99.85% Sb · 25 kg ingots
Refining Equipment
Primary Smelting Vessel
Reverberatory Furnace
Gas-fired reverberatory furnaces produce crude antimony and antimony trioxide (Sb₂O₃) from roasted stibnite charge. Operating range 900–1,000°C with controlled reducing atmosphere.
♨
High-Purity Refining Unit
Graphite-Lined Reactor
Chlorination refining reactors use corrosion-resistant graphite lining to withstand antimony trichloride (SbCl₃) at process temperatures, enabling distillation-grade purity separation.
⬡
End-Use Markets

Applications

Antimony's unique combination of hardness, low melting point, and chemical reactivity makes it irreplaceable across five high-value industrial sectors — from battery manufacturing to specialty glass.

Sector 01
Battery Manufacturing
Lead-acid battery grids — improved mechanical strength
Hardening agent extending battery cycle life
Automotive & industrial UPS batteries
Emerging sodium-antimony energy storage
01
Sector 02
Fire Retardants
Synergist with halogen compounds in plastics
Flame-retardant coatings for textiles & upholstery
Antimony trioxide (Sb₂O₃) in cable sheathing
Construction materials & foam insulation
02
Sector 03
Alloys & Metallurgy
Hardening agent in lead, tin and copper alloys
Babbitt bearing metal (Sb–Pb–Sn)
Pewter and britannia metal compositions
Type metal for printing & precision casting
03
Sector 04
Electronics & Semiconductors
InSb infrared detectors & Hall effect sensors
N-type dopant in germanium semiconductors
GaSb for mid-infrared laser diodes
Diode & thermoelectric device components
04
Sector 05
Glass & Ceramics
Decolouring agent in specialty optical glass
Fining agent removing bubbles from glass melts
Antimony oxide opacifier in enamels
UV-absorbing glass for laboratory & medical uses
05
Competitive Advantage

Why Choose United Metals?

Four pillars that distinguish United Metals as the preferred antimony ingot supplier for global industrial buyers.

High Purity & Quality
Every ingot is consistently refined through volatilisation roasting and chlorination refining to achieve 99.65–99.85% Sb purity. Comprehensive testing — XRF spectrometry, weight certification, and mill certificates — accompanies every shipment.
Reliable Dual-Origin Sourcing
Direct operations across Zimbabwe and India's top mining and refining facilities provide supply-chain redundancy and year-round availability — critical in a market where antimony supply is increasingly geopolitically constrained.
Competitive Pricing at Scale
Cost-effective solutions for bulk industrial requirements, with volume pricing structures available for long-term supply agreements. Pricing is referenced to SMM FOB antimony ingot benchmarks ensuring market-competitive terms.
Global Logistics Support
Seamless export operations to worldwide destinations, with full documentation — packing lists, certificate of origin, mill certificates, and dangerous goods classification (UN 3077) compliance — provided for smooth customs clearance in all major markets.
Market Intelligence

Market Insight

The global antimony market is experiencing a structural price surge driven by critical mineral designation, Chinese export restrictions, and accelerating demand from flame retardant and battery sectors.

Global Market · 2024
$2.3B
Current global antimony market valuation as of 2024, projected to grow to USD 3.7 billion by 2033.
Industry Research · 2024
CAGR · 2022–2029
6.7%
Projected compound annual growth rate for the antimony market through 2029, reaching USD 3,698 million.
Market Forecast · 2022–2029
SMM FOB · 99.65% · Current
$22.5K
Antimony Ingot 99.65% FOB price per Shanghai Metal Market. Prices surpassed USD 40,000/mt in late 2024 before partially correcting.
SMM · Feb 2025

Committed to Precision & Reliability

At United Metals, we are committed to delivering high-quality antimony ingots with precision, reliability, and sustainability. Our direct smelting operations in Zimbabwe and India provide one of the most vertically integrated antimony supply chains outside of China.

Partner with us for your industrial-grade antimony needs — from spot purchases to long-term supply agreements tailored to your production schedules.

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