How is cinnabar concentrated before mercury is extracted?

Cinnabar, the primary ore of mercury, is typically concentrated using mineral-processing techniques such as jigging, shaking, screening, elutriation, and flotation.1

While these methods can produce higher-grade concentrates, they are often not economically competitive with the direct furnacing of ore that has been sorted by hand or processed as mined. This is partly because cinnabar is soft and friable; the crushing and grinding required for flotation can lead to significant losses of the mineral as slimes. Consequently, many operations prefer to bypass extensive concentration steps in favor of direct pyrometallurgical extraction.12