Editing Copper extraction (section)

===Froth flotation===
{{main|Froth floatation}} 
[[File:FlotationFalconbridgeOnt.jpg|thumb|Froth flotation cells to concentrate copper and nickel sulfide minerals, Falconbridge, Ontario.]]
[[File:Prominenthill-flotation.jpg|thumb|Copper sulfide loaded air bubbles on a [[Jameson Cell]] at the flotation plant of the [[Prominent Hill]] mine in [[South Australia]]]]

In froth flotation, the crushed ore is wetted, suspended in a slurry, and mixed with reagents that render the sulfide particles [[hydrophobic]]. Typical reagents ("collectors") include [[potassium ethylxanthate]] and [[sodium ethylxanthate]], but [[dithiophosphate]]s and dithiocarbamates are also used. The slurry is introduced to a water-filled aeration tank containing a [[surfactant]] such as [[4-Methyl-2-pentanol|methylisobutyl carbinol]] (MIBC). Air is constantly forced through the slurry. The air bubbles attach to the hydrophobic copper sulfide particles, which are conveyed to the surface where the froth is skimmed off. These skimmings are generally subjected to a cleaner-scavenger cell to remove excess silicates and to remove other sulfide minerals that can deleteriously impact the concentrate quality (typically, [[galena]]), and the final concentrate is sent for smelting. The rock that has not floated off in the flotation cell is either discarded as [[tailings]] or further processed to extract other metals such as lead (from galena) and zinc (from [[sphalerite]]), should they exist. A variety of measures are taken to improve the efficiency of the froth flotation. [[Lime (material)|Lime]] is used to raise the [[pH]] of the water bath, causing the collector to bond more efficiently to the copper sulfides. The process can produce concentrates with 27–29% and 37–40% copper contents from [[chalcopyrite]] and [[chalcocite]], respectively.