Dense medium separation (DMS) is a newer processing technology which grew in popularity during the 1950-1970’s as many companies used it to replace inefficient jigging processes for separating coal, iron and other ores. From the conversations I have had with current and potential customers about DMS technology it is obvious that though it is a well proven method for preconcentration and concentration duties, many people are not aware of how it works or the strong benefit they stand to gain from this simple, but effective, process.

What is DMS?

Dense medium separation (DMS), also known as dense or heavy media separation, is a beneficiation technology that has been used for many years in the processing and mining industry. It utilizes the difference in material density between liberated particles as the separation mechanism. Essentially, particles with a higher specific gravity can be separated from particles with a lower specific gravity.

What is used to make the dense medium?

Dense medium, also referred to as “heavy liquid” is made up from the mixture of water and very fine and dense powder. The two most common dense powders used are ferrosilicon (FeSi) and magnetite (Fe3O4) which remain suspended in water during the separation process. This mixture then acts as a high density medium. The density can be varied by changing the ratio of water and powder in the mixture.

The reason why ferrosilicon and magnetite are used is because of their magnetic properties which make it easy to recover and re-circulate within the plant.