Consider the Al2O3SiO2 phase diagram to answer the following questions: a) (i) What is the phase composition of a fireclay-type material of composition 60% SiO240%Al2O3 at room temperature? (ii) What is the solidus temperature of this fireclay-type material (of composition 60%SiO240%Al2O3) ? b) (i) What is the phase composition of an alumina-based material of composition 95%Al2O35%SiO2 at room temperature? (ii) What is the solidus temperature of this alumina-based material (of composition 95%Al2O35%SiO2 )? c) What can you conclude from the information obtained in a(ii) and b(ii)? Under which conditions will you use the respective materials? d) Comment on the influence of Al2O3 as an impurity component on the refractoriness of SiO2-based materials. Do this by determining the amount of liquid present in the material at 1600C, if it contains 1 mass %Al2O3. e) Indicate what the solidus temperatures for different compositions in this system are. Draw these on the phase diagram