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Why are spiral concentrators useful for processing gold ores and heavy mineral sands?

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mineral processing Schematic diagram of a flotation separation cell.

Spiral concentrators are highly effective for processing gold ores and heavy mineral sands due to their efficiency in handling fine-grained particles, typically ranging from 1 millimeter down to 50 micrometers.1

These devices utilize a vertical spiral channel with an oval cross section to separate minerals based on density differences. As the ore pulp flows downward, centrifugal force acts upon the material, causing the heavier, valuable particles to concentrate along the inner side of the stream, where they are easily collected through specialized openings.1

Beyond their technical capability to separate dense minerals from lighter gangue, spirals are favored in mineral processing because they offer low energy costs and simplicity of operation. This makes them a practical choice for large-scale operations, such as the initial concentration of heavy mineral sands in titanium processing.12