21-Mat-A3 Structure and Characterization of Materials, December 2019: worked solutions

Paper format. National Exams, December 2019 — 10-Met-A3, Metal Extraction Processes. Three hours, closed book, one approved calculator (Casio or Sharp). Seven problems of 20 marks each; the rubric asks for any five, and only the first five in the answer book are marked. All seven are solved here, because this set is a study resource rather than an exam script.

Note on the exam title. The printed exam header reads 10-Met-A3, Metal Extraction Processes. The content is extractive metallurgy — mineral processing, mass and heat balances, pyrometallurgical roasting, refining, magnesium production and electrometallurgy — and is answered as such.

Note on the data. The Question 6 iron heat-balance data set (C_p expressions and transformation enthalpies for α/β/γ/δ-Fe) uses a mass of 55.85 kg (chosen so it equals exactly 1000 mol) and temperature endpoints of 160–1735 °C, crossing the 1535 °C melting point into the liquid.

Reference texts. The answers below are keyed to the works normally recommended for this syllabus code:

F. Habashi, Textbook of Pyrometallurgy — roasting, refining, mass and heat balances.
T. Rosenqvist, Principles of Extractive Metallurgy, 2nd ed. — thermal and electrolytic reduction, electrometallurgy, refining.
B. A. Wills and J. Finch, Wills' Mineral Processing Technology, 8th ed. — pulp density, gravity/electrostatic separation, froth flotation.
D. R. Gaskell, Introduction to the Thermodynamics of Materials — heat capacities, transformation enthalpies, electrochemistry.
ASM Handbook, Vol. 15 (Casting) and CIM (Canadian Institute of Mining, Metallurgy and Petroleum) practice literature for Canadian smelter and refinery practice.

21-Mat-A3 Structure and Characterization of Materials: December 2019