$2$ of $3$

$2.$ The projection of the liquidus surface of the ternary system MgO$-A{l}_2{O}_3-Si{O}_2$ is shown below;

a$)$ For composition $),$ what is the amount of solid phase at $1600C?$ What are your suggestions to reduce the amount of solid phase by keeping temperature constant? $(15$p$)$

b$)$ For composition $,$ what is the amount and composition of liquid phase at temperature where periclase starts to crystallize? $(15$p$)$

c$)$ A glass material whose starting composition is $80wt\%Si{O}_2-16wt\%$MgO$-4$ wt $\%A{l}_2{O}_3$ will be melted at $1700C.$ Is it possible to produce glass under these conditions? Explain briefly. $(20$p$)$