Raw materials

Question 1

What raw materials are used in soda lime glass?

Answer 1

~ sand (SiO2), limestone (CaCO3), and soda ash (Na2CO3)

Question 2

What’s the rxn for the solvay process?

Answer 2

~ 2NaCl + CaCO3 –> Na2CO3 + CaCl2

Question 3

What is a substitution for limestone?

Answer 3

~ dolomite (Ca, Mg)CO3

Question 4

What is a substitution for soda ash?

Answer 4

~ feldspar (granite, quartz, mica)

~ feldspar is liberated by crushing and separating by froth floatation (quartz is also generated and used as source of silica)

Question 5

What is borax used for?

Answer 5

~ source of soda and boria

~ in e-glass, which intolerant of alkali, boric acid (borax + HCl) is used

Question 6

What is iron in terms of raw materials?

Answer 6

~ BA, makes glass green

~ optical glasses can’t have more than 0.015% Fe2O3 impurity

Question 7

How can iron introduced from crushing and grinding machinery be removed?

Answer 7

~ magnets

Question 8

How can iron present in the original rock be removed?

Answer 8

~ with hot concentrated sulfuric acid (expensive)

~ used only when lots of freedom from iron oxide is required