Laboratory Sub-Aeration Flotation Machine

What is the Laboratory Sub-Aeration Flotation Machine?

A laboratory sub-aeration flotation machine disperses air supplied from an external blower through a mechanical impeller, giving independent control of agitation and aeration. It is the standard bench unit for ore flotation testing.

Overview

The machine comprises a cell of one to three litres, a vertical shaft with an impeller and a diffuser hood, a motor with variable speed control and an air line fitted with a flow meter and valve. Air is supplied by a small blower or from the laboratory compressed air line rather than induced by the impeller, which allows air rate and impeller speed to be varied independently and so separates mixing from aeration effects. Froth is removed either by hand with a paddle or by a rotating scraper mounted on the cell rim. pH, temperature and pulp level are monitored, and reagents are added from syringes or peristaltic pumps at recorded times. Because the cell geometry is fixed, results are comparable between testers, and cell volumes can be changed by fitting different tanks to the same drive.

How does it work?

Froth flotation separates particles by their surface chemistry. The ore is ground to a size at which the target mineral is liberated, mixed with water to form a pulp of a chosen solids concentration, and conditioned with collectors that make selected minerals hydrophobic and frothers that stabilise bubbles. Air is dispersed into the pulp, either by a mechanical impeller that draws air from above or by forced air through a sparger, and hydrophobic particles attach to rising bubbles to form a froth that is scraped off as concentrate. Hydrophilic particles remain in the pulp and are discharged as tailings. Bench equipment therefore needs controllable agitation, aeration, pH and reagent addition, plus a cell that allows froth to be removed at a steady rate. Results are scaled up using retention time, solids concentration and reagent dosage per tonne, with grinding and liberation established separately by the ore's size distribution.

What are the key features?

• External air supply with flow meter and control valve
• Variable impeller speed independent of aeration
• Interchangeable cells of 0.5 to 3 litres
• Rotating froth scraper or manual paddle option
• pH and temperature monitoring during the test
• Mounted reagent dosing point on the cell rim

What are the technical specifications?

A typical laboratory sub-aeration flotation machine configuration offers cell volume of 0.5–3 L, impeller speed of 0–2000 rpm, variable, air flow rate of 0–10 L/min adjustable, pulp density range of 10–50 % solids by mass, feed particle size of < 2 mm, typically < 150 µm and sample mass per test of 200–1000 g. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Laboratory Sub-Aeration Flotation Machine is used in reagent screening and dosage optimization, rougher and cleaner batch flotation tests, pH and grind size response studies and routine plant feed flotation testing. Across the wider Flotation Equipment class, laboratories also deploy it for reagent scheme development for ore bodies, rougher, cleaner and scavenger circuit configuration and grind size and liberation optimization.

Which standards and certifications apply?

Relevant standards and methods include ISO 8858-1, ASTM D5114, ISO 3082, ISO 12743, ASTM E877 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Calibrate and record the basic variables with every test: solids concentration, grind size distribution, pH, reagent dosages, air flow, impeller speed and flotation time. Rinse the cell and impeller thoroughly between tests, because residual collector changes the next result, and use consistent water quality, since dissolved ions affect flotation strongly in recycled plant water. Check impeller clearance and wear, air spargers, scraper blades and pH electrodes on a schedule. Provide splash guards, eye protection and fume extraction for reagent and acid handling, and store collectors and frothers safely. For result transfer to plant, run replicate tests and report grade and recovery with the metal balance closed; locked-cycle or cycle tests are then used to estimate steady-state performance before any plant trial.

How do I select the right Laboratory Sub-Aeration Flotation Machine?

Select the sub-aeration machine when you need to vary air rate and agitation independently, which is essential in reagent and kinetics studies. Specify cell volumes, impeller speed range, air flow range, scraper type and the reagent dosing arrangement you will use.

How does it compare with other Flotation Equipment variants?

Start from the ore mass available and the question to be answered. A single self-aerating or sub-aeration cell of one to three litres suits reagent screening, pH and dosage tests with a few hundred grams of sample. Multi-cell banks of three to eight cells are used for rougher, cleaner and scavenger configurations or for locked-cycle tests that approximate a continuous circuit. Flotation columns suit fine particles and cleaner duties where a deep froth and wash water give better grade. Conditioning tanks are needed whenever reagents require contact time before flotation, which is often the decisive step for collector performance. Check impeller and air-flow ranges against the pulp density you will use, whether froth scraping is manual or automatic, and whether the machine can hold pH, temperature and air rate stable enough for reproducible recoveries. Plan reagent dosing and water supply as part of the package.