Spodumene is an important lithium ore resource and one of the industrial ores for lithium extraction. The two commonly used methods for spodumene ore beneficiation are gravity separation (heavy media separation) and flotation. This article compares the principles and commonly used equipment of these two beneficiation methods to help you understand which method is better.
Principle of Gravity Separation (Heavy Media Separation): Gravity separation exploits the density differences between ore and gangue minerals. Based on the varying specific gravities of different minerals, gravity separation uses a heavy medium (such as water or heavy medium suspension) to separate spodumene from gangue minerals. The method includes heavy media separation and gravity separation. In heavy media separation, adjusting the density of the suspension enables spodumene with higher density to sink, while lighter gangue minerals float, achieving separation. In gravity separation, forces like vibration or water flow are used to make the heavier spodumene settle, separating it from lighter gangue minerals.
Principle of Flotation: Flotation adjusts the surface properties of ore and gangue minerals in water to selectively adsorb or inhibit them, achieving separation. The ore is ground into fine particles, mixed with water and flotation reagents to form a flotation suspension. Flotation reagents change the surface properties of mineral particles, allowing hydrophobic spodumene particles to adsorb on bubbles and rise to the liquid surface, forming a spodumene flotation froth, while gangue minerals sink to the bottom. Separation of spodumene from gangue is achieved by collecting spodumene particles from the froth.
How to Choose Between Gravity Separation and Flotation: Gravity separation is suitable for coarse separation based on density differences, while flotation is suitable for selectively separating minerals at the fine particle level. The choice between the two methods depends on ore characteristics, particle size, impurities in the ore, and other factors. Sometimes, a combination of multiple separation methods is used to enhance separation efficiency and extraction rates.
Equipment for Gravity Separation
Heavy Media Hydraulic Cyclone: Used for heavy media separation, creating a cyclonic motion in the heavy medium suspension to separate materials based on density differences.
Ore Dressing Shaking Table: Utilized for separating materials based on density and particle size. It uses pulsating water flow and a particle bed to stratify and separate heavier and lighter materials.
Spiral Chute: Utilizes the spiral flow of water to separate materials based on density and particle size. Suitable for gravity separation of fine particles.
Equipment for Flotation
Flotation Machine: The primary equipment used in flotation separation. Equipped with agitators, it generates bubbles to facilitate the attachment of hydrophobic particles (such as spodumene) to bubbles. Different types of flotation cells, such as mechanical cells, column cells, and pneumatic cells, can be used depending on the specific flotation process.
Froth Scraper and Scraper: Used for collecting and removing froth or concentrate from flotation cells. Aids in separating hydrophobic particles (such as spodumene) and froth while recovering the desired ore concentrate.
Reagent Mixing and Conditioning Equipment: Various reagents are added during the flotation process to promote the selective attachment of desired particles. Mixing and conditioning equipment, such as stirring tanks, are used to prepare and optimize the flotation reagent mixture.
Air Compressor: Used to generate bubbles in flotation cells. These bubbles attach to hydrophobic particles, carrying them to the liquid surface for collection.
The choice of equipment depends on factors such as operational scale, process requirements, technological advancements, and economic considerations, and a comprehensive evaluation is necessary to make the final decision.
