Icap 7400 radial

The analytic process for the liquid sample during the (bio)dissolution process is shown in Fig. 1a. The dissolved Fe²⁺ and Fe³⁺ were quantified through the o-phenanthroline spectrophotometry method^{40 (link)} with a microplate reader (BOX 998, Biotek Instruments, HIGHLAND PARK, USA). Iron, Cu²⁺, and Zn²⁺ concentrations were analyzed by inductively coupled plasma-atomic emission spectrometry (ICP-AES) (ICAP-7400 Radial, Thermo Fisher Scientific, MA, USA); meanwhile, the pH and oxidation–reduction potential (ORP) values were monitored with a pH meter (PHSJ-4A, Shanghai LEICI Co., Shanghai, China) and ORP meter (BPH-221, Dalian BELL Co., Dalian, China), respectively. The bacterial density was detected using a hemocytometer in a bright field microscope (CX31RTSF, Tokyo OLYMPUS Co., Tokyo, Japan). The mineralogical contents of bornite and marmatite were detected by XRF (Axios MAX, PANalytical B.V., Almelo, Holland). All electrochemical experiments were performed by electrochemical TAB (CHI700E, Shanghai CH Instruments, Shanghai, China). The mineralogical phases of bornite, marmatite and the residues were analyzed by SR-XRD at beam line of 4B9A of the Beijing Synchrotron Radiation Facility (BSRF). The mineralogical changes were detected by a confocal micro-Raman spectrometer (inVia Qontor, Renishaw, United Kingdom).

The elemental analysis of raw material was carried out by X-ray fluorescence (XRF, XRF-1800, Shimadzu, Kyoto, Japan, instrument working voltage 40 kV, working current 95 mA, prt 8 mL min⁻¹). The crystalline phases and surface morphology of raw material and important solid roasted material were examined and scanned by X-ray diffraction (XRD, TTRAX III, Japan, Cu-Kα radiation, tube current 700 mA, tube voltage 40 kV, step sizes 0.2°, scanning range 2θ = 5°–90°, scanning rate 10° min⁻¹), scanning electron microscopy (SEM, Nova NanoSEM 450, FEI, USA, acceleration voltage: 50 V to 30 kV, magnification 20–1000k). The aluminum content in aluminum liquid was determined by an inductively coupled plasma-optical emission spectrometer (ICP-OES, ICAP7400 Radial, Thermo Scientific, USA). The carbon contents analysis was performed via an infrared carbon and sulfur analyzer (CS 2000, ELTRA, Germany). The particle size distribution was measured using Rise-2002 laser particle size analyzer (Jinan Runzhi Technology Co., Ltd.).