According to the 2026 Global Mining Equipment Operation and Maintenance Report, over 80% of small and medium-sized mines have encountered problems with the mismatch between flotation machines and mineral types/production capacity. This can lead to an average decrease in ore beneficiation recovery rate of 8%-15%, translating to annual revenue losses of several million yuan. High-end configurations waste budgets, while low performance delays production. This article provides an in-depth analysis of the world’s mainstream mechanical agitation and aerated flotation machines, comparing them across multiple dimensions, including performance advantages, structural characteristics, and applicability. Understanding the differences between the two and their optimal matching scenarios will help you avoid 90% of the pitfalls in flotation machine selection.
There are two main types of flotation machines: mechanically agitated flotation machines are the most widely used in small- and medium-sized copper, lead, and zinc mines. Aerated flotation machines (including flotation columns) are currently the core choice for fine-grained mineral separation.
Basic concepts of flotation machines
Flotation machines are core equipment in mineral processing, specifically designed for the industrial separation of minerals. There are two common types of flotation machines: mechanically agitated and aerated. Both primarily utilize froth flotation technology to efficiently extract target mineral particles from complex ore mixtures. However, mechanically agitated flotation machines rely on impeller shear force to generate bubbles, while aerated flotation machines are supplied with air via an external compressed air system.
The working principle of a flotation machine utilizes the difference in hydrophobicity of mineral surfaces: under agitation and aeration, target mineral particles adhere to the bubbles, rise with the froth layer to the surface, and are collected, while gangue minerals settle to the bottom and are discharged.
Process Steps:
A typical flotation machine workflow can be divided into four key steps:
- Pulp agitation and aeration: The impeller rotation creates turbulence, while air is introduced to generate bubbles.
- Selective mineral adhesion: Hydrophobic mineral particles (such as chalcopyrite) adhere to the bubble surface.
- Froth layer formation: The ore-laden bubbles rise, forming a stable froth layer at the top of the tank.
- Concentrate recovery and tailings discharge: A scraper collects the frothy concentrate, and tailings are discharged from the bottom.
Core Function:
Flotation is currently the most widely used fine-grained mineral separation process in the global mineral processing industry, and it is also the core step determining the grade and recovery rate of the final product from metallic/non-metallic minerals. Especially in the processing of high-value, difficult-to-process minerals such as lithium, rare earth, and precious metal ores, the flotation process contributes more than 70% of the total value output. As the core carrier of the flotation process, the performance parameters of the flotation machine, such as aeration uniformity, stirring intensity, and tank structure, directly affect production efficiency, mineral recovery rate, and unit operating cost.
2. Scheelite flotation process
2 main types of flotation machines details
Type 1: Mechanically Agitated Flotation Machine
Principle and Structure:
The core power unit of a mechanically agitated flotation machine consists of an impeller, stator, and tank system. During operation, the impeller rotates at high speed, creating a negative pressure zone within the tank, automatically drawing in air and generating a large number of bubbles. Simultaneously, the intense agitation ensures thorough contact between the slurry and the bubbles, causing valuable minerals to adhere to the bubble surface and float to the froth layer, where they are ultimately collected by a scraper. Currently, mainstream models in China include the SF/BF/XCF/KYF series. This “forced aeration + mechanical agitation” design makes it suitable for processing high-density, coarse-grained ores, adapting to the configuration requirements of almost all mineral processing procedures.
Core Advantages:
Its modular design supports multi-tank series connection, meeting the needs of processing millions of tons of ore annually.
The strong agitation force provided by the impeller effectively prevents the settling of coarse minerals, making it suitable for the separation of high-density ores with a density greater than 4 g/cm³.
The self-priming model can achieve gravity flow configuration without the need for an auxiliary slurry pump, offering extremely high flexibility for process adjustments during line relocation and capacity expansion.
Applicable Scenarios:
The mechanically agitated flotation machine is suitable for more than 70% of the needs of small and medium-sized mineral processing plants in China, most typically for roughing and scavenging operations of coarse/high-density ores such as gold, lithium, antimony, copper, lead-zinc, and iron ore. In addition, it is also suitable for small and medium-sized concentrators with multiple process stages requiring frequent process adjustments, as well as for the separation of complex ores such as high-concentration slurries with a concentration greater than 40% and polymetallic associated lead-zinc-copper ores.
Type 2: Aerated Agitated Flotation Machine
Principle and Structure:
The core difference between aerated flotation machines and mechanically agitated flotation machines lies in their non-mechanical aeration design. Its core operating logic is an external high-pressure air supply combined with a dedicated microbubble generator. Air is forcibly injected through an external high-pressure blower or air compressor, forming tiny bubbles via a microporous diffuser. The slurry contacts these bubbles in the relatively static tank, causing mineral particles to adhere and float, achieving separation. Aerated agitated flotation machines retain a low-speed agitation structure, maintaining coarse particle suspension capabilities. However, by eliminating the high-speed impeller structure, energy consumption is significantly reduced, making them particularly suitable for processing fine-grained minerals (such as gold and platinum group metals).
Key Advantages:
Regarding microbubble mineralization efficiency, for fine-grained minerals smaller than 0.045mm, the recovery rate can be increased by 4-5 percentage points compared to traditional mechanical agitation. In some high-grade gold ore beneficiation scenarios, the enrichment ratio can reach more than 20 times.
Without a high-power impeller drive structure, the overall energy consumption is 30-50% lower than that of mechanical agitation systems with the same capacity.
Applicable Scenarios:
The air-filled flotation machine is precisely suited to the current efficiency improvement needs of the mineral processing industry. Its core application is the fine-grained/difficult-to-process ores such as gold, molybdenum, and bauxite. It is particularly suitable for precious metal flotation purification, increasing recovery rates from 81% to 90%. Furthermore, it is also applicable to low-grade material separation scenarios such as coal desulfurization and tailings resource recovery.
For coarse-grained, high-density ores, small to medium-sized concentrators, and complex multi-stage processes, mechanically agitated flotation machines with strong stirring power and flexible configurations are preferred. For fine-grained, difficult-to-process ores, large-scale concentrators, and low-grade tailings recovery scenarios, aerated flotation machines/columns with high microbubble efficiency and lower energy consumption are preferred. The combination of these two types of flotation machines in a “roughing + cleaning” process can simultaneously achieve good recovery rates and concentrate grades. When selecting a flotation system, refer to a comparison of the two types of flotation equipment, prioritizing a comprehensive judgment based on ore properties, production capacity, and budget planning.
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