ZHAO Ming-rui, LIU Hai-bo*, CHEN Tian-hu, ZOU Xue-hua, CHEN Dong, ZHAO Yue-ling, LI Meng-xue, WANG Ling-kai
(School of Resources & Environmental Engineering, Hefei University of Technology, Hefei 230009, China)
Abstract:Natural limonite, siderite, hematite, and magnetite were used as raw materials to prepare zero-valent iron (ZVI) by the hydrogen reduction roasting at 600 ℃. In this paper, with the application of X-ray diffractometer (XRD), X-ray fluorescence spectrometer (XRF), specific surface area and pore structure analyzer, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier Transform infrared spectroscopy (FTIR), we have studied characteristics of mineral component of iron-rich ore and morphology, specific surface area and pore structure of the prepared product of the ZVI, investigated influences of contact time, initial phosphorous concentration, and pH value on the phosphorous enrichment, analyzed the release capacities of Pb(Ⅱ), Cu(Ⅱ), and Hg(Ⅱ) from the iron-rich ore at pH values of 3 and 5, and explored the enrichment properties and mechanism of phosphorus in the ZVI. The results show that the ZVI prepared from magnetite has relatively high content of iron (Fe2O3 87.4%), less impurities, a large number of micro-nano pores, and no detectable Pb(Ⅱ), Cu(Ⅱ), and Hg (Ⅱ) released from raw ore sample within 15 days. Moreover, the ZVI prepared from magnetite also has the best phosphorous enrichment effect, with up to 13.45 mg/g of phosphorous. Phosphorous of the ZVI can be leached out from the ZVI by the 2.2 mol/L NaOH solution for recovery at recovery rate of 99.9%. The surface complexation and electrostatic adsorption of phosphorous, and co-precipitation of phosphorous and Fe(Ⅱ)/Fe(Ⅲ) produced by the Fe oxidation is the main mechanism for enrichment of phosphorous in the ZVI. This research result is helpful to promote the comprehensive utilization of iron-rich ore and its application in the advanced treatment of phosphorous or the recycling of phosphorous resource.
Keywords: Iron-rich ore; mineral component; zero-valent iron (ZVI); phosphorous; comprehensive utilization
ACTA MINERALOGICA SINICA Vol.41, No.6, 2021, page 685-696
