PGM Flotation explained
Flotation is a critical operation in PGM mineral processing operations. Platinum group metals (PGMs) are a group of six elements, namely iridium (Ir), osmium (Os), platinum (Pt), palladium (Pd), rhodium (Rh) and ruthenium (Ru). Extraction of PGM’s comprises of metallurgical and mineral processing steps to follow in order to economically separate the valuable minerals from the gangue. The first used method in PGMs extraction is comminution, which obviously means reduction of size particles through crushing and grinding, followed by froth flotation. These steps are the primary means of attaining PGM’s either through laboratory scale flotation or in a PGM concentrator plant.
The term, which is widely used, for the beneficiation process of PGM’s is Froth flotation. Froth flotation in general is a highly versatile method for physically separating particles based on differences in the ability of air bubbles to selectively adhere to specific mineral surfaces in a mineral/water slurry. The particles with attached air bubbles are then carried to the surface and removed as froth. In this case, PGM concentrates while the particles that remain completely wetted stay in the liquid phase and is regarded as Gangue/Tails or the unwanted material.
Froth flotation can also be adapted to a broad range of mineral separations, as it is possible to use chemical treatments to selectively alter mineral surfaces so that they have the necessary properties for the separation. In the PGM industries, flotation is the key element which is utilized for the beneficiation process, however for the flotation system to happen, there are components that play a fundamental role known herein as chemistry, equipment, and operation components. The PGM flotation process needs chemistry to take place. In this regard, the following chemistry components are needed:
- Collectors
- Frothers
- Activator
- Depressants
- pH
The second component which plays a key role when one must conduct PGM flotation either in a concentrator plant or in the laboratory, is the operations component where one must consider the mineralogy of the ore, feed rate, pulp density and particle size to successfully perform the flotation process.
The third component is the equipment component, which entails of cell design, agitation airflow, cell bank configuration and cell bank control. These components may sound confusing, but they play hand in hand to successfully float PGM’s and other minerals.
How does PGM flotation work? 
PGM containing pulp/ slurry will be introduced into an agitating flotation cell at a known density, feed rate and particle size. The chemistry components/ reagents are then introduced, which will play a role to enhance the PGM minerals hydrophilic or hydrophobic. These terms simply means that water loving and water repellent respectively. In this case, collectors, depressants and frothers are used all together to float PGM’s. The floated PGM’s will be collected as froth on the launders of the flotation cell. The product will then be filtered and dried in preparation for assay to determine the grade of the PGM product. The assayed PGM product can then be classified as 4E or 6E, in this case Pt, Pd, Rh and so on.
We are a Metallurgical testing lab with years of industry experience and are more than willing to help you find the perfect reagent.
At Metsop, we believe that in order to fully optimize performance we must not only provide an effective specialty chemical, but also a complete service solution. To realize the best performance possible, we work closely with our customers to understand both the environment and the application in which our chemicals are being used, and how the environment changes over time. To support this process, we have developed a broad range of services to help our customers optimize their performance potential.
Our team of field and laboratory technical experts have a deep understanding of both our chemistry and the processes that use our chemistry. Their depth of expertise enables us to get to the root of our customers’ problems and realize step changes in performance.
