Metallurgy Questions

During the process of electrolytic refining of copper, some metals present as impurity settle as 'anode mud'. These are:

Heating a mixture of ${\text{Cu}}_2\text{O}$ and ${\text{Cu}}_2\text{S}$ will give:

Which one of the following ores is best concentrated by the froth – floatation method?

Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly?

Which method of purification is represented by the following equation:
$$\text{Ti(s)}+2{\text{I}}_2\text{(g)}\stackrel{523\text{K}}{\to }{\text{TiI}}_4\text{(g)}\stackrel{1700\text{K}}{\to }\text{Ti(s)}+2{\text{I}}_2\text{(g)}$$