Question $1$

a$)$State the reasons for drying wet concentrates before shipping to smelters?

b$)$Outline the stages through which drying proceeds?

c$)$List the factors which affect the rate of drying?

d$)$Distinguish between co$-$current and counter$-$current drying, citing examples?

e$)$What is the "kernel effect"?

QUESTION $2$

a$)$ What are the qualities of a good slag?

b$)$ Distinguish between a basic slag and an acidic slag?

c$)$ Explain why Cr does not reduce Al$2$O$3$ using an Ellingham diagram?

d$)$ Explain why the curve for the formation of CO$2$ is a straight line on the Ellingham diagram?

e$)$ Differentiate between chloridizing roast and chlorinating roast, use equations?

QUESTION $3$

a$)$ Outline the functions of coke in the iron making blast furnace?

b$)$ Explain why coal is not used as a substitute for coke during iron making?

c$)$ Explain whether the furnace atmosphere in the blast furnace is oxidizing or reducing?

d$)$ Describe the electric smelting furnace, include its advantages over the fuel fired reverberatory furnace?

Question $4$

a$)$ State the generic reactions that govern sulphide smelting?

b$)$ What are the objectives of matte smelting?

c$)$ Outline the main features of the Outokumpu flash smelting furnace, use a diagram?

d$)$ Identify the features which distinguish the INCO flash smelting furnace and the Outokumpu flash smelting furnace?

Question $5$

a$)$ Why is converting necessary after matte smelting?

b$)$ Why is iron not completely converted to iron oxide during roasting?

c$)$ Describe the operation of the Pierce$-$Smith converter?

d$)$ Describe the problems associated with magnetite formation during smelting and converting?

Give possible solutions and equations