Study on Preparation of Oxygen Carrier Using Copper Slag as Precursor

Abstract

Copper slag, an important by-product of the copper smelting process, is mainly composed of 2FeO SiO2, Fe3O4, and SiO2. Due to the sufficient metal oxides, copper slag is regard as a potential oxygen carrier (OC), which can be applied in chemical looping technology. This research proposed to use the granulated copper slag particles as precursor to produce oxygen carrier. Through this method, waste heat of the high-temperature slag can be fully recovered, eliminating the complicated copper slag pretreatment process. In this paper, the reactivity of granulated copper slag after redox calcination was studied by X-ray diffractometer (XRD) and Scanning Electron Microscope (SEM), the highest reactivity occurred at 1,000°C. In addition, the oxygen release and absorption performance of OC were tested in thermal-gravimetric (TG). According to theoretical calculations, the mass loss caused by oxygen release accounts for 70.57% of the total loss and the mass reached by 4.2% at 1,000°C in oxygen absorption experiment. The copper slag modified through calcining in redox condition was proved to be a promising oxygen carrier in chemical looping process. Furthermore, the performance research on OC also provided theoretical references for the operating paraments of OC circulating between air reactor and fuel reactor in practical chemical looping processes.

An Unbiased Approach to Low Rank Recovery

“…Iron sand was first calcined in air in a high-temperature furnace at 950 • C for 12 h to improve its reactivity and mechanical strength [25]. The calcined oxygen carrier was then sieved to the size range 125 -180 µm and subsequently activated at 850 • C for a minimum of 4 redox cycles in the fluidized bed batch reactor prior to any investigations to ensure the fuel conversion stability [26].…”