Technical support

Heavy Media Separation Process

Heavy media separation is a well-established density separation process, ideally suited for the separation of minerals, ores and scrap metals, with specific gravities ranging from 2 – 4.5. Modern dense media plants use a suspension of dense powder in water to act as an artificial ‘heavy liquid’ in separating mineral particles in a sink-float process. Ferrosilicon powders with a relative density of 6.7-7.1 containing 13-16% silicon are commonly used as the dense powder.

The production of ferrosilicon suitable for dense medium separation processes requires sophisticated production and quality control techniques, which must incorporate tight control on chemical composition as well as physical properties. The use of ferrosilicon produced in this fashion as a medium, provides the following benefits:

• Corrosion resistance
• Abrasion resistance
• Magnetic properties allowing efficient recovery and easy demagnetization
• High specific gravity
• Economical operating costs

General Guidelines for the selection of a Ferrosilicon Grade

DMS Powders produces a wide range of grades to suit any application. The different grades have different physical properties, which determine in-circuit behavior. These properties should be correctly matched to the type of dense medium process being used and the nature of the required separation.

The more important properties of the dense suspension or ‘medium’, i.e. powder mixed with water to form heavy liquid, are density, viscosity and stability, which are interrelated. These properties are determined by the physical properties of the ferrosilicon powder, such as particle size distribution and shape, controlled in the production process to produce a wide range of products. The impact of ferrosilicon properties on that of the medium can be briefly described as follows:

1. Medium Density
2. Medium Viscosity
3. Medium Stability
4. Selection of the medium

Back to Atomised Ferrosilicon | Milled Ferrosilicon supplier | FeSi | DMS Powders