Mineral processing is a core part of mineral extraction, serving as the mechanical and chemical pathway that transforms raw ore into a concentrated, marketable product. Often referred to as mineral dressing, this stage relies on advanced techniques, methods, and technology to separate valuable minerals from the surrounding material.
Why Is Mineral Processing Important?
Effective mineral processing directly influences the profitability of a mining operation. The more efficiently valuable minerals can be concentrated, the more viable a project becomes. If sufficient yields of targeted minerals cannot be achieved, the project will not advance to full development.
Mineral processing technology is used to extract and concentrate a wide range of metals, industrial minerals, stones, and building materials, including:
• Metals such as iron, copper, gold, nickel, silver, zinc, bauxite, and chromite
• Rocks such as coal, granite, clay, limestone, marble, potash, and sand
• Industrial minerals such as quartz, carbonates, talc, barite, garnet, fluorite, zircon, and gemstones
Ultimately, mineral processing transforms ore into usable material for further refining and everyday applications.
What Are the 4 Stages of Mineral Processing?
To turn heterogeneous ore into a homogeneous, high-quality concentrate, operations follow four primary mineral processing steps. Each step relies on specialized mineral processing equipment that varies depending on ore type, mineral characteristics, and processing objectives.
1. Crushing and Grinding
Crushing and grinding, also known as comminution, reduce large rocks into smaller, workable particle sizes. Crushers and grinding mills break down the ore to prepare it for the next stages of separation and classification.
2. Sizing and Classification
Once crushed, ore particles are separated based on size. Screens and classifiers sort fine materials from coarse materials, ensuring each stream moves into the appropriate downstream process.
3. Concentration
The concentration stage isolates valuable minerals from gangue material. Different techniques and methods are used depending on the ore’s physical or chemical properties, including:
- Automated ore sorting using sensors to categorize material.
- Electrostatic separation, which charges dry particles for separation.
- Froth flotation, which uses reagents and air bubbles to collect hydrophobic minerals.
- Gravity separation, using density differences.
- Magnetic separation, utilizing magnetic forces with wet or dry applications.
These mineral processing methods increase the percentage of valuable minerals in the processed material.
4. Dewatering
Once concentrated, the material still contains significant moisture. Dewatering equipment, such as thickeners, filter presses, and dryers, removes water to achieve the final concentrate quality required for transport, smelting, or refining.
How Mineral Processing Works
After ore is brought to the surface, haulers deliver large rock fragments to primary crushers. These machines break the rock down to roughly 15 cm (6 in) pieces, which are moved via conveyor belts to stockpiles near the concentrator.
Inside the concentrator building, grinding mills such as SAG mills further reduce the ore, either using water to form slurry or processing it dry. Materials are then sent through sizing screens, where particles smaller than 1.3 cm (½ in) move forward, and larger fragments return to pebble crushers or grinding circuits.
The finer material proceeds to ball mills for further size reduction. Cyclones then separate coarse particles from fine ones. Coarse ore returns for regrinding, while fine material advances to the concentration stage.
During concentration, minerals are refined to a powder-like consistency. They pass through thickeners and filtration mineral processing equipment to remove water, followed by drying to achieve the targeted concentrate grade. This final product is often then transported to off-site facilities for smelting or further processing.
Mineral Processing Equipment
Advanced mineral extraction relies on highly specialized mineral processing equipment at each stage. These systems are selected based on ore characteristics, required throughput, and the desired level of separation efficiency.
Crushing and Grinding
This stage reduces large chunks of ore into smaller, manageable particle sizes to prepare them for downstream mineral processing steps. The goal is to achieve uniform fragmentation so minerals can be effectively exposed and liberated.
• Jaw crushers
• Gyratory crushers
• Cone crushers
• SAG mills
• Ball mills
• Rod mills
• Pebble crushers
Sizing and Classification
After comminution, materials must be sorted by size to ensure proper flow through the processing circuit. These technologies separate coarse particles from fine ones and direct each stream to the correct processing stage.
• Vibratory screens
• Banana screens
• Grizzlies
• Fine screens
• Hydrocyclones
• Spiral classifiers
• Trommels
• Ore sorters
Concentration
Concentration equipment isolates valuable minerals from gangue by using various physical and chemical techniques. These systems increase the percentage of targeted minerals to create a higher-grade product.
• Roughers
• Cleaners
• Recleaners
• Scavengers
Dewatering
Once minerals are concentrated, excess moisture must be removed to achieve the required marketable product quality. Dewatering equipment reduces water content for efficient handling, transport, or further refining.
• Dewatering screens
• Thickeners and clarifiers
• Filter presses
• Rotary dryers
• Spray dryers
These mineral processing equipment support the full range of mineral processing, delivering consistent material flow and high-quality separation.
Mineral Separation Equipment from STET
Looking for a quicker, easier way to process minerals? Use STET’s electrostatic separation equipment. We provide state-of-the-art mineral processing equipment to our customers and help them achieve higher-value mineral extraction with advanced dry separation technology.
Want to learn more? Contact us today!
