Optimization of staged bioleaching of low-grade chalcopyrite ore in the presence and absence of chloride in the irrigating lixiviant: ANFIS simulation

Abstract

In this investigation, copper was bioleached from a low-grade chalcopyrite ore using a chloride-containing lixiviant. In this regard, firstly, the composition of the bacterial culture media was designed to control the cost in commercial application. The bacterial culture used in this process was acclimated to the presence of chloride in the lixiviant. Practically speaking, the modified culture helped the bio-heap-leaching system operate in the chloridic media. Compared to the copper recovery from the low-grade chalcopyrite by bioleaching in the absence of chloride, bioleaching in the presence of chloride resulted in improved copper recovery. The composition of the lixiviant used in this study was a modification with respect to the basal salts in 9 K medium to optimize the leaching process. When leaching the ore in columns, 76.81 % Cu (based on solid residues of bioleaching operation) was recovered by staged leaching with lixiviant containing 34.22 mM NaCl. The quantitative findings were supported by SEM/EDS observations, X-ray elemental mapping, and mineralogical analysis of the ore before and after leaching. Finally, Adaptive neuro-fuzzy inference system (ANFIS) was used to simulate the operational parameters affecting the bioleaching operation in chloride-sulfate system.

Leaching of Copper Concentrate with Iodized Salts in a Saline Acid Medium: Part 1—Effect of Concentrations

“…Several methods have been used to increase reaction rates and break or avoid this passivation layer in leaching systems, including (i) leaching with powerful oxidizing agents such as O 3 [ 30 , 31 , 32 ], H 2 O 2 [ 6 , 33 , 34 , 35 ], potassium permanganate, and potassium dichromate [ 36 , 37 , 38 ], (ii) leaching with high pressure and temperature [ 34 , 39 , 40 , 41 ], and (iii) bacterial leaching [ 11 , 14 , 42 , 43 ], but these improvements are accompanied by limitations, mainly due to the high cost of oxidizers, the corrosive environments they provide and even low copper recoveries [ 39 , 44 ]. These kinds of considerations result in the hydrometallurgical route not being widely used in the dissolution of copper from primary sulfide ore, mainly because of slow leaching kinetics caused by the crystal structure of chalcopyrite (face-centered tetragonal lattice), which makes its lattice energy too high to break S-Cu-Fe bonds [ 23 , 45 ].…”

Effect of externally adding pyrite and electrical current on galvanic leaching of chalcopyrite concentrate

“…Chalcopyrite (CuFeS2) is the main source of copper, and about 70% of the world's copper produces from porphyry copper deposits (Wang, 2005) that full-scale hydrometallurgical processes are under developments so far (Petersen, 2016;Vakylabad et al, 2016). A wide variety of hydrometallurgical methods have been considered to address issues involved in the leaching of chalcopyrite-bearing ore types.…”

“…A wide variety of hydrometallurgical methods have been considered to address issues involved in the leaching of chalcopyrite-bearing ore types. For example, bioleaching (Vakylabad et al, 2016), pressure-leaching (Li et al, 2018), and Galvanox™ (Dixon et al, 2008) processes are widely reported in the literature. The first industrially commercial application was high-temperature and pressure leaching of Phelps-Dodge process (Marsden et al, 2003) developed at Bagdad, Arizona, U.S.A, in 2003.…”

“…Regardless of the process, principle concern in conjunction with its leaching is a slow and incomplete dissolution of the mineral. This is mainly because of the formation of passive layers like polysulfide, metal-deficient sulfides, iron hydroxysulfate species, and elemental sulfur (S 0 ) on its surface (Nazari, 2012;Khoshkhoo et al, 2014;Klauber 2008;Vakylabad et al, 2016;Vakylabad et al, 2012, Hassanzadeh et al, 2021. These passive layers render electron transfers from chalcopyrite to pyrite and limite galvanic reactions.…”

Underground Development of Mineral Subsoil Using Microorganisms: A Mini-Review

“…Underground Development of Mineral Subsoil Using Microorganisms: A Mini-Review Computational Fluid Dynamics (CDF-Simulation) [23], ANN modeling (Artifi cial Neural Network Modeling) [24], or ANFIS-simulation [25] can be used for this purpose. Th e last of these approaches is the most progressive, accurate, and highly productive way of modeling, but it brings to a unifi ed industrial level suitable for all possible scenarios of bacterial leaching processes and requires further improvement of analytical algorithms.…”