Practical considerations: we’ll take each of these one by one. So location within the milling circuit, we talked about this a little bit in the first video, “Where to Install a Gravity Concentrator in a Flotation Plant.” Traditionally, these have gone in the underflow. However, the more modern placement is in the feed for a couple reasons. Now, the first reason is the efficiency of the unit. We talked about how this isn’t the hugest thing as long as the cyclone’s operating well, but one of the things we have to definitely keep in mind when it comes to the percent solids is the screening. So we’re going to talk a little bit more about screening here, but you are probably not going to get extremely efficient screening with a heavily loaded screen and 70% solids.

What that effectively does is bypasses the concentrator if you’re not able to screen efficiently. So we’ve got the concentrator here, the gravity concentrator underneath the screen, feeds coming on. It needs to go through the screen to get to the concentrator, but if we’re just tossing gold particles over and they’re bypassing the concentrator, you’re not even going to get a chance at them. So for a couple reasons, 1) screen efficiency and 2) concentrator efficiency, we want to get that concentrator in the feed because it’s a more dilute stream and we can get closer to this 45%, 50% solids range. Especially once we include the spray water for the screen, we can get this to a good point where the concentrator is going to be efficient. The screen is going to be efficient and the circuit together is going to be operating a lot better.

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