The latest in our video series on the technical paper “Gravity recovery of gold from within grinding circuits” is about the importance of screening prior to the gravity concentrator within a circuit. Watch the short video above to see Dr. Andrew Gillis’s explanation and interpretation of this topic within the paper; video transcript is available below.


Screening and G-Force: so the industry is pretty much standardized on 2 mm apertures. First off, most operations aren’t going to have gold particles larger than 2 mm, and second – wear cost starts to get out of control when you’re above that size. Basically, if we have wear and particle size, it starts going like this, and – this is really qualitative – but 2 mm might be here. And if you start going 3, 4, 5, 6 mm, you’re getting way up the curve here.

That’s pretty good as far as getting good open area, moving stuff through the screen, preventing wear. And unless there’s some real reason to screen at a larger size, like huge 6 mm nuggets of gold, in the grinding circuit you want to be down here at 2 mm or maybe 1.5 mm or similar just to limit wear on the concentrators.

If you found this video interesting please visit our website to find the extended video series, as well as additional shorter clips, addressing specific points around gold recovery for milling circuits. Thanks very much for watching.