21-Mat-B1 Hydrometallurgy and Electrometallurgy, Undated paper: worked solutions

Paper format. National Exams, May 2019 — 10-Met-B1, Mineral Processing. Three hours, closed book, approved Casio/Sharp calculator only. Four questions constitute a complete paper: Question 1 (15 marks), Question 2 (20 marks: (1) 5, (2) 15), Question 3 (25 marks: (1) 15, (2) 10), Question 4 (40 marks: any 8 of 10 short items at 5 marks each). All ten items of Question 4 are answered below.

Note on the exam title

Nothing on the paper is a hydrometallurgy (leaching, solvent extraction, electrowinning) or electrometallurgy question; the syllabus actually examined is comminution/grinding-circuit mass balance, screening and classification, gravity concentration and froth flotation — the physical/mechanical beneficiation stage that precedes hydro- or pyro-metallurgical extraction.

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

B. A. Wills and J. A. Finch, Wills' Mineral Processing Technology, 8th ed. — two/three-product metallurgical accounting (Ch. 3), comminution and Bond's third law (Ch. 6), screening and partition (Tromp) curves (Ch. 8), sampling theory/Gy's equation (Ch. 3), classification and hydrocyclones (Ch. 9), gravity concentration (Ch. 10), froth flotation reagents and surface chemistry (Ch. 12).

21-Mat-B1 Hydrometallurgy and Electrometallurgy: Undated paper