Q$1.$ Chromite ore $(-650$ micron particle size$)$ of $15\%C{r}_2{O}_3$ is fed at the flowrate of $1200$

tons$/$h to a beneficiation circuit consists of spiral concentrators at two stage such as

rougher and cleaner. Rougher concentrate of the spiral is treated in cleaner spirals while

its tailing is sent to the final tailing. The cleaner tailing of $20\%C{r}_2{O}_3$ is recirculated to the

rougher spiral and circulating load is $0\mathrm{.}50($recycle$/$fresh feed$).$ The $C{r}_2{O}_3$ grade of the

cleaner spiral concentrate is $31\%$ with a recovery of $65\%.$

a$)$ Draw a simple flowsheet $(5$ pts$)$

b$)$ Calculate the flowrates and grades of all missing streams. $(18$pts$)$

c$)$ What do you suggest to obta in a sa lable chromite concentrate having at least $48\%C{r}_2{O}_3$

from that spiral cleaner concentrate? $(5$ pts$)$

d$)$ What should be done to the material prior to the spiral concentrator feeding? Explain

the reasons $(5$ pts$)$