Question

What is the temperature maintained in Hall-Heroult process?

(a) 800°-840° C

(b) 840°-880° C

(c) 900°-940° C

(d) 940°-980° C

I have been asked this question in exam.

The question is from Electrochemical Principles of Metallurgy topic in portion General Principles and Processes of Isolation of Elements of Chemistry – Class 12

Answer 1

Right choice is (d) 940°-980° C

The best explanation: A high temperature of about 1100°C need to be maintained to keep the electrolyte in molten state but mixing the electrolyte with feldspar and cryolite brings down the temperature to about 940° – 980° C and also increases conductivity.