Open AccessInfluence of jarosite precipitation on iron balance in heap bioleaching at Monywa copper mine
Author(s) -
Кяв Мин Соэ,
Ренман Руан,
Янь Цзя,
Цяой Тан,
Чжентан Ван,
Цзяньфэн Ши,
Чуанган Чжонг,
Хэюн Сун
Publication year - 2021
Publication title -
zapiski gornogo instituta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.707
H-Index - 13
eISSN - 2541-9404
pISSN - 2411-3336
DOI - 10.31897/pmi.2020.1.11
Subject(s) - jarosite , bioleaching , chemistry , leaching (pedology) , precipitation , sulfate , heap leaching , potassium , supersaturation , copper , nuclear chemistry , metallurgy , inorganic chemistry , geology , materials science , physics , organic chemistry , meteorology , soil science , soil water
Ferric iron is an important oxidant in sulfide ore bioleaching. However, recirculating leach liquors leads to excess iron accumulation, which interferes with leaching kinetics and downstream metal recovery. We developed a method for controlling iron precipitation as jarosite to reduce excess iron in heap bioleaching at Monywa copper mine. Jarosite precipitation was first simulated and then confirmed using batch column tests. From the simulations, the minimum pH values for precipitation of potassium jarosite, hydronium jarosite, and natrojarosite at 25 °C are 1.4, 1.6, and 2.7, respectively; the minimum concentrations of potassium, sulfate, ferric, and sodium ions are 1 mM, 0.54, 1.1, and 3.2 M, respectively, at 25 °C and pH 1.23. Column tests indicate that potassium jarosite precipitation is preferential over natrojarosite. Moreover, decreased acidity (from 12 to 8 g/L), increased temperature (from 30 to 60 °C), and increased potassium ion concentration (from 0 to 5 g/L) increase jarosite precipitation efficiency by 10, 5, and 6 times, respectively. Jarosite precipitation is optimized by increasing the irrigating solution pH to 1.6. This approach is expected to reduce the operating cost of heap bioleaching by minimizing the chemicals needed for neutralization, avoiding the need for tailing pond construction, and increasing copper recovery.