Mineral processing flow of molybdenum ore

Molybdenum is an important strategic metal widely used in fields such as steel, alloys, chemicals, and electronics. The beneficiation process of molybdenum ore is a crucial step in extracting high-purity molybdenum concentrate. This process is complex and refined, involving multiple stages. Below is a detailed explanation of the molybdenum ore beneficiation process, covering ore crushing, ore grinding, classification and washing, flotation separation, concentrate dewatering, molybdenum concentrate purification, and smelting and refining.

1. Ore Crushing
   Ore crushing is the first step in the molybdenum ore beneficiation process, aiming to reduce large chunks of ore to a suitable particle size for subsequent processing. This stage typically involves coarse crushing using jaw crushers or gyratory crushers, followed by medium and fine crushing with cone crushers or impact crushers until the ore reaches the required particle size for grinding. During crushing, attention must be paid to controlling the crushing ratio and minimizing over-crushing to improve grinding efficiency and recovery rates.

   

2. Ore Grinding
   Grinding is the process of further refining the crushed ore to fully liberate valuable minerals from gangue minerals, creating favorable conditions for subsequent separation processes. Commonly used grinding equipment includes ball mills, rod mills, and autogenous mills. Parameters such as grinding concentration, media ratio, and grinding time must be strictly controlled to achieve optimal grinding results. Additionally, energy consumption should be managed to enhance grinding efficiency.

   

3. Classification and Washing
   Classification and washing involve the size separation and cleaning of the ground ore slurry. Through equipment such as vibrating screens or hydrocyclones, coarse and fine particles in the slurry are separated. Meanwhile, wash water is used to remove clay and fine gangue from the mineral surfaces, improving the concentrate grade. The effectiveness of classification and washing directly impacts the recovery rate and concentrate quality in subsequent flotation processes.

   

4. Flotation Separation
   Flotation is the core step in molybdenum ore beneficiation. It leverages differences in the physicochemical properties of mineral surfaces by adding flotation reagents and introducing air with agitation. This causes valuable minerals to attach to air bubbles and rise to the slurry surface, forming a froth layer, while useless minerals such as gangue remain in the slurry, achieving separation. In the flotation of molybdenum ore, appropriate flotation reagents and processes, such as preferential flotation or bulk flotation followed by separation, must be selected based on the ore properties to enhance the recovery rate and grade of molybdenum concentrate.

   

5. Concentrate Dewatering
   The molybdenum concentrate obtained from flotation contains a significant amount of water and requires dewatering for storage and transportation. Common dewatering methods include thickening, filtration, and drying. Thickening removes free water from the concentrate through gravity settling or centrifugal action; filtration uses media such as filter cloths to trap solid particles and further remove moisture; drying involves heating the concentrate to a certain temperature using hot air or thermal radiation to eliminate residual water.

6. Molybdenum Concentrate Purification
   Molybdenum concentrate purification is the process of further increasing the purity of the concentrate, typically by removing impurities through chemical or physical methods. Chemical purification includes steps such as leaching, purification, and precipitation, where impurities are separated from the main mineral through chemical reactions. Physical purification methods include gravity separation, magnetic separation, and electrostatic separation, which leverage differences in the physical properties of minerals for separation. The purified molybdenum concentrate has a higher grade and is more suitable for subsequent smelting and refining.

7. Smelting and Refining
   Smelting is the process of converting purified molybdenum concentrate into metallic molybdenum or molybdenum alloys. Commonly used smelting methods include pyrometallurgy and hydrometallurgy. Pyrometallurgy mainly involves roasting, reduction, and smelting, where molybdenum is precipitated in metallic or alloy form through high-temperature reactions. Hydrometallurgy uses chemical reagents to react with molybdenum in the concentrate, forming soluble molybdenum salts, which are then extracted as metallic molybdenum through electrolysis or precipitation. Refining involves further purification and treatment of the smelted metallic molybdenum or molybdenum alloys to meet the requirements of various applications for molybdenum products.