$($i$)$ Describe gravity concentration process either on the shaking table or the Wemco drum separator $[6]$

$($ii$)$ Discuss the various functions of reagents that are used in flotation $[6]$

$($iii$)$ The flotation circuit shows some flowrates and grades of the streams. Given that the upgrade or enrichment ratio $($concentrate grade$/$feed grade$)$ is $9$ calculate: $($a$)$ Tailings flowrate $[2]$ and $($b$)$ Concentrate grade $[6]$