alumina from bauxite

Question 1

What are the five steps of the bayer process to purify extract and manufacture alumina from bauxite

Answer 1

first step is to crush the bauxite

Next the crushed bauxite Reacts with NaOH (Sodium hydroxide) at 170 °C to form NaAl(OH)4 (Sodium aluminate)

Next solid impurities are filtered out

Next you wait for crystallisation to form Al(OH)3 (Aluminium hydroxide)

Finally its heated in rotary kiln to form Al2O3

Question 2

What happens to most of the alumina separated in the bayer process

Answer 2

The alumina separated using the bayer process is used in the hall heroult process to form aluminium by electrolysis

Question 3

Why does the temperature during the bayer process needs to be 170°C for alumina from bauxite

Answer 3

Because at 170°C the alumina is dissolved

Question 4

In the bayer process what is the equation for alumina with sodium hydroxide

Answer 4

Al2O3 + 2NaOH → 2NaAl(OH)4 + 3H2O