21-Mat-B1 Hydrometallurgy and Electrometallurgy, December 2014: worked solutions

Paper format. National Professional Examinations, December 2014 — 10-Met-B1, Mineral Processing. Three hours, closed book, approved Casio/Sharp calculator only. Six numbered Problems (all compulsory except Problem 5) plus a two-mark Bonus Question. Problem 5's rubric asks for any SIX of eleven sketch-and-describe topics; all eleven topics 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 and grinding-circuit mass balance, particle settling, flotation kinetics, and mineral-processing equipment/terminology — the physical/mechanical beneficiation stage that precedes hydro- or pyro-metallurgical extraction.

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

B. A. Wills and J. A. Finch, Wills' Mineral Processing Technology, 8th ed. — comminution and Bond's law (Ch. 6), classification and hydrocyclones (Ch. 9), gravity concentration and jigs (Ch. 10), froth flotation and flotation kinetics (Ch. 12), dense-medium separation and thickening (Ch. 11, 17).
F. F. Aplan (ed.), SME Mineral Processing Handbook — flotation reagents (collectors, frothers, activators), plant flowsheets, comminution circuit design.
A. Taggart, Handbook of Mineral Dressing — classical terminology (probable error, ratio of concentration/enrichment, jig hutch, crusher types).
J. Svarovsky, Solid-Liquid Separation — particle sizing methods, hydrocyclone theory, thickening.

21-Mat-B1 Hydrometallurgy and Electrometallurgy: December 2014