Multotec Hydrocyclones Australia

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Hydrocyclones, also known as ‘cyclones’, from Multotec Australia are used across the continent in mining and mineral processing, manufacturing, aggregates, food processing, wastewater management, and other industries. In mineral processing, they are used for classifying particles based on size and density. In the mining sector, cyclones are used for a range of applications, including separating ore from waste, removing heavy minerals from slurry, and dewatering tailings.

With branches in Brisbane, Mackay, Newcastle, Newman, Perth, and Emerald, Multotec Australia is perfectly positioned to aid with all of your mineral processing cyclone requirements. Our hydrocyclones are used by international mining giants like Xstrata, Fortescue Metals, BHP Billiton, Oceania Gold, FQM, Rio Tinto, and AngloCoal, to sort and classify a variety of minerals including, but not limited to, aluminium, chrome, coal, copper (oxide & sulphide), diamonds, gold, graphite, vanadium (high & low grade), iron ore, lithium-tantalum, manganese, mineral sands, nickel, PGM, phosphates, tantalum, tin, uranium, and Zinc.

How do hydro cyclones work?

Using centrifugal force and gravity, hydrocyclones create a vortex of moving liquid in order to separate particles according to their size and density. Heavier particles gravitate to the bottom of the hydro-cyclone and lighter ones, ideally, remain suspended near the top of the cyclone chamber. The suspended particles’ light weight means that they can be discharged via overflow pipes at various heights, which is determined by the particle size requirements.

Hydrocyclone for particle size separation

The particle size requirements would have been determined by the specific downstream application requirements such as filtration and sedimentation, for example. The coarse material migrates to the centre of the hydro-cyclone and moves downwards through the spigot.

Why use a hydrocyclone?

Hydro cyclones can bring joy to the lives of those who use them, or it can be a frustrating piece of equipment! This is according to cyclone product specialist at Multotec Ernst Bekker. You can watch the video here.

So, why use a hydrocyclone? Bekker says that in some people’s minds, a hydrocyclone should be the perfect classifier, but that is not always the case. Perfect classification looks like this:

The cut point of the hydrocyclone is defined as 50% of the particle size reporting either to the overflow or the underflow. On the curve that you see on the image above – the left-hand side is the fines fraction and the right-hand side is the coarser fraction. As you can see on the Y axis on the left-hand side, it recovers to the underflow. In reality, this is the type of separation that starts to take place with the cut point at the 50% mark.

However, as we don’t achieve perfect separation, particles are misplaced. Coarse particles are misplaced to the overflow and fine particles to the underflow. Another factor that plays a role in the hydrocyclone separation efficiency is bypass water, which can be seen in the bottom left of the above image. It is necessary to always have water in the underflow, as the more water you have, the more fines report to the underflow. Because of this, Multotec, as hydrocyclone manufacturers and suppliers, discount the bypass water effect and use a curve that we refer to as the corrected separation curve. As hydrocyclone suppliers and manufacturers, we use two different cut points. Our focus is on the actual cut point which, in client simulations, is referred to as the D50 corrected cut point.

The objective in hydrocyclone classification is to have the unit operating at maximum efficiency. Bear in mind that, just because there is material reporting to both the overflow and underflow, it does not mean that the unit is operating efficiently.

The red line in the above graph shows the overflow and size distribution of a hydro-cyclone’s operating efficiency. The dotted line shows the overflow size distribution of a hydrocyclone that is not operating efficiently, and the green line is the flotation recovery response per particle size. (This example is based on copper ore, and shows the difference between a cyclone with low efficiency and one with high efficiency.) The economic impact, on an annual basis, is significant – and bear in mind that this is for illustrative purposes only, and will differ from process to process. The bottom line is that you may think that your hydrocyclone is operating efficiently, but you may be losing money.