Flotation machine

Based on the difference of mineral surface wettability, the flotation machine is a core beneficiation equipment that allows target minerals to attach bubbles and float up into foam and gangue slurry by means of agent modification and aeration stirring, so as to realize the separation of valuable minerals from waste rocks. It is widely used for the separation of copper, lead, zinc, gold, molybdenum, coal, non-metallic ores, etc.

1、 Core working principle (three-step sorting)
● Slurry preparation: Grind the ore into slurry by adding water, then add a collector (to make the target ore hydrophobic), a foaming agent (to stabilize bubbles), and an adjusting agent (pH/to suppress gangue).
● Inflatable stirring mineralization: The impeller stator rotates at high speed, sucks in/presses in air and crushes it into microbubbles; Mineral particles collide with bubbles, hydrophobic mineral particles firmly adhere to the bubbles (mineralization), hydrophilic gangue does not stick and sinks to the bottom.
● Separation and scraping: mineralized bubbles float up to form a foam layer, and the scraper scrapes out concentrate; The non floating slurry is discharged from the bottom as tailings, and multiple tanks are connected in series to complete rough selection, sweeping selection, and fine selection, improving the grade and recovery rate.

2、 Mainstream types (classified by inflation+mixing method, most practical)
1. Self priming mechanical stirring type (self-priming, XJK/SF/JJF/Wemco)
● Principle: The rotation of the impeller generates negative pressure, allowing for self suction of air and slurry without the need for an external fan/sand pump.
● Advantages: Self flow configuration, simple process, convenient return of intermediate ore, easy maintenance.
● Disadvantages: Small inflation volume, narrow adjustment range, high energy consumption, and fast impeller wear.
● Applicable: Small and medium-sized beneficiation plants, easily floatable sulfide ores, coarse/sweep beneficiation, no additional inflation required.
2. Inflatable mechanical stirring type (pressure type, KYF/CHF/XJC/Denver)
● Principle: The external fan forces air in, and the impeller only stirs and disperses bubbles, not responsible for suction.
● Advantages: Large inflation volume, precise and adjustable, low rotational speed, low energy consumption, minimal wear, stable liquid level, and strong scalability.
● Disadvantages: Requires a blower, no self-priming slurry capacity, and requires a sand pump for ore lifting.
● Applicable: The preferred choice for large-scale beneficiation plants, complex polymetallic ores such as copper/lead/zinc/gold, high concentration/coarse particles, and fine selection.
3. Flotation column (without mechanical stirring, column type)
● Principle: Bottom inflation (microporous/swirling), slow rise of bubbles, counter current collision of mineral particles, no impeller, low energy consumption, good fine particle selection.
● Advantages: High grade concentrate, low reagent consumption, small footprint, suitable for fine particles (<0.045mm).
● Disadvantages: Small processing capacity, poor adaptability to coarse particles/high concentrations, easy blockage, and need for stable ore feeding.
● Applicable: Selected operations, non-metallic ore (quartz/feldspar) impurity removal, coal slurry, difficult to select fine-grained metal ores.
4. Spray/swirl type (XPM/coal slurry specific)
● Principle: High speed slurry injection, self-priming air, good bubble dispersion, strong stirring, suitable for coal slurry, and easy to float fine particles.
● Advantages: High inflation efficiency, low energy consumption, non clogging, preferred for coal slurry sorting.

3、 Core Structure (Mechanical Stirring Standard Configuration)
● Tank body: accommodates slurry, with a single tank capacity of 0.5-160m ³, and multiple tanks connected in series.
● Impeller stator assembly: Core - Impeller rotation stirring, suction/dispersion of bubbles; Stator stable flow, anti swirl, and enhanced mineralization.
● Inflation system: self-priming (air duct)/compressed air (fan+air duct).
● Foam scraping mechanism: motor+scraper to continuously scrape out concentrate foam.
● Liquid level/discharge control: gate/valve, adjust the slurry level and tailings discharge.
● Transmission system: motor, reducer, spindle, driving impeller.

4、 Key performance parameters
● Single tank capacity: 0.5~160m ³ (the larger the capacity, the more suitable it is for large-scale beneficiation plants).
● Inflatable capacity: 0.5~1.5 m ³/(m ² · min), adjustable pressure type, self-priming fixed.
● Impeller linear velocity: 6-8 m/s (balancing mixing and wear).
● Applicable particle size: conventional 0.074-0.5mm; flotation column is suitable for fine particles<0.045mm.
● Slurry concentration: 25%~40% (optimal sorting range).

5、 Advantages and disadvantages
● Advantages
High sorting accuracy and high recovery rate (up to 90%+for non-ferrous metals).
Widely applicable: sulfide ore, oxide ore, precious metals, coal, non-metallic minerals can all be used.
Multiple metals can be sorted step by step (copper → lead → zinc floating in sequence).
Mature pharmaceutical system, flexible process, and easy automation.
● Disadvantages
Dependence on pharmaceuticals, cost and environmental protection need to be controlled.
The requirement for grinding fineness is high (over grinding and mudification, under grinding and flotation).
Self suction has high energy consumption/wear and tear; The flotation column has limited processing capacity.
Fine mud and high viscosity slurry are prone to running out of the groove and poor sorting.

6、 Typical application scenarios
● Nonferrous metals: copper, lead, zinc, nickel, molybdenum, cobalt sulfide ore selection (most mainstream).
● Precious metals: gold, silver flotation (associated sulfide ore).
● Black metals: hematite, specularite (reverse flotation desilication).
● Coal: coal slurry flotation, ash reduction/desulfurization.
● Non metals: phosphate ore, potassium salt, fluorite, quartz/feldspar for iron removal and purification.
● Environmental protection: tailings recycling, heavy metal removal from wastewater.

7、 Key points of selection
● Ore properties: sulfide ore → mechanical stirring; Fine particles → flotation column; Coal slurry → jet type.
● Scale: Large scale selection plant → Pneumatic filling (KYF/Denver); Small and medium-sized → self-priming.
● Homework section: rough selection/scanning selection → strong mixing and large processing capacity; Selection → flotation column/low agitation.
● Condition: Water shortage/no fan → self-priming; Pursuing low energy consumption/high stability → compressed air type.