Another practical consideration here is the plant height. If you have a concentrator that is on the cyclone underflow, everything’s going to stack underneath that. So you’re going to go: screen, cyclone, then screen on the next level. So we’re going to have a level for the cyclones, a level for the screen, a level for the concentrator, tails go somewhere, concentrate goes somewhere.

So all this is up in the air. If you rather – let’s say you’ve got multiple cyclones, and one of these is just a blind flange that is then going to the concentrator. You can actually bring everything up. This illustration isn’t great, but you can use that pressure to get everything up, put the screen on the same level as the cyclones.

Then you have your concentrator up on the level that the screen was on and everything is moved up one floor. Or on the other hand, everything, the cyclone pack has been able to go down one floor and your overall plant height is then reduced; building height is reduced.

From a design point of view, if you’re targeting, let’s just say, 10% to 30% of that circulating load, this is a pretty good place. If you start going up higher, then you’re going to have, then you will have too much material bypassing the mill in its own little gravity circuit here. Then you probably will practically want to go to underflow.

But if you’re 10%, 20% treated from population balance model, it’s not going to be a huge deal to have this little gravity circuit. And it’s certainly going to be of economic benefit being able to lower the overall plant height. So that’s a primary reason why, in modern designs, it’s more common to have the concentrator on the cyclone feed rather than the cyclone underflow,

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