Nickel Mining Process: From Ore to Refined Metal

Nickel-ore-flotation

This article provides a comprehensive overview of the nickel mining process, including types of nickel ores, extraction methods, beneficiation techniques, and environmental considerations.

The nickel mining process begins with identifying the right type of ore. Nickel occurs primarily in two ore types:

A. Sulfide Ores

• Typically found deep underground

• Rich in nickel, copper, and often cobalt

• Easier to process with traditional smelting techniques

• Major deposits: Sudbury Basin (Canada), Norilsk (Russia), and Voisey’s Bay (Canada)

B. Laterite Ores

• Found near the surface, formed in tropical climates

• Comprise limonite (iron-rich) and saprolite (silicate-rich) layers

• Require more energy-intensive processing

• Major deposits: Indonesia, Philippines, New Caledonia

Key difference: Sulfide ores are preferred for high-grade applications, while laterite ores dominate global reserves due to abundance.

Depending on the ore type and deposit depth, mining operations use either underground or open-pit mining.

A. Open-Pit Mining (Laterite)

• Large-scale surface excavation

• Cheaper and faster for shallow laterite ore bodies

• Typically used in Indonesia, the Philippines, and Australia

B. Underground Mining (Sulfide)

• Room-and-pillar or block caving methods

• Used for deeper sulfide ores

• Higher initial investment, but cleaner ore and less surface disruption

Modern mines also use automated drilling, GPS-controlled trucks, and remote monitoring systems to improve efficiency and safety.

After mining, raw ore must be processed to increase nickel concentration and remove impurities. The beneficiation stage differs for sulfide and laterite ores.

A. Sulfide Ore Beneficiation

1. Crushing & Grinding: Break ore into smaller particles

2. Froth Flotation: Use chemicals to separate nickel-rich minerals from waste rock

3. Dewatering: Remove excess water from concentrate

Nickel concentrate from flotation typically contains 10–20% nickel, ready for smelting.

B. Laterite Ore Beneficiation

Laterite ores are more complex and can’t be concentrated by flotation. They follow two main routes:

• HPAL (High Pressure Acid Leach)

• Pyrometallurgy (Ferronickel/Nickel Pig Iron)

The extracted concentrate or laterite slurry undergoes further processing to isolate pure nickel. Here's how:

A. Processing of Sulfide Nickel Ores

1. Smelting: Roast and melt concentrate to produce matte (nickel + copper + iron)

2. Converting: Blow air or oxygen to oxidize iron and sulfur, leaving rich nickel matte

3. Refining: Use hydrometallurgy (leaching) or electrorefining to produce high-purity nickel metal (up to 99.9%)

This process is cost-effective for high-grade ores and results in valuable by-products such as copper and platinum group metals.

B. Processing of Laterite Nickel Ores

Option 1: High Pressure Acid Leach (HPAL)

• Crushed ore mixed with sulfuric acid under high temperature (250°C) and pressure (up to 5 MPa)

• Produces mixed hydroxide precipitate (MHP) or mixed sulfide precipitate (MSP) containing nickel and cobalt

• Common in battery-grade nickel production

Option 2: Ferronickel/Nickel Pig Iron (NPI) Production

• Suitable for saprolite ore

• Ore smelted in electric furnaces at high temperature (~1,600°C)

• Produces ferronickel, a direct feed for stainless steel production

The nickel mining process is a complex chain of activities that converts earthbound ore into a refined metal critical to modern life. As the world transitions to clean energy, the pressure to mine and process nickel responsibly grows stronger.

Want to learn more about building or investing in a nickel processing plant? Contact our expert team for feasibility studies, equipment sourcing, and EPC services tailored to your project.