1
|
Li C, Yang X, Li Y, Chen Y, Pan X, Xie Y, Liu X, Li S. Preparation of high-purity SiO 2 by S-HGMS coupled with mixed-acid leaching: A case study on hematite tailings from Ansteel, China. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 174:240-250. [PMID: 38070443 DOI: 10.1016/j.wasman.2023.11.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/10/2023] [Accepted: 11/22/2023] [Indexed: 01/16/2024]
Abstract
Hematite tailings (HTs) are rich in silica and are used as replacements for fine aggregates in the preparation of construction materials. However, there is scope for a more effective utilization of the valuable elements present in HTs. In this paper, a process for preparing high-purity SiO2 using HTs procured from Ansteel (China) is proposed. HTs were treated using the superconducting high-gradient magnetic separation (S-HGMS) technology, where the silica as part of the nonmagnetic fraction was obtained in the form of a high-silica concentrate, which was then subjected to mixed-acid leaching to dissolve impurities to achieve refined purification. The optimum process conditions for S-HGMS were determined, and the response surface methodology was applied to optimize the process parameters of the mixed-acid leaching process. The process indicators of the mixed-acid leaching step included the leaching time, leaching temperature, and molar ratio of the mixed acids. The optimum process conditions for S-HGMS were as follows: the magnetic strength-to-velocity ratio in the weak magnetic separation stage was set to 0.034 T·s/m whereas it was maintained at 0.076 T·s/m in the strong magnetic separation stage; the pulp concentration was 40 g/L, the pulp velocity was 500 mL/min, and the dispersant concentration was 1 mg/g. Under these conditions, the high-silica pulp was processed. The corresponding SiO2 grade increased from 71.788 % to 95.260 %, and its recovery and yield reached 56.330 % and 42.450 %, respectively. The SiO2 content in the sample increased from 95.260 % to 99.961 %. Further, the mechanisms of the S-HGMS and mixed-acid leaching were revealed. The proposed process is environmentally friendly and operationally inexpensive. It can reduce the amount of HTs by 42.450 %, and the obtained high-purity silica product has high economic value and good industrialization prospects.
Collapse
Affiliation(s)
- Cong Li
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Xiaofeng Yang
- Ansteel Group Beijing Research Institute Co., Ltd, Beijing 100083, China
| | - Yongkui Li
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yu Chen
- Ansteel Mining Engineering Corporation, Beijing 100083, China
| | - Xiaodong Pan
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yongping Xie
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Xingyu Liu
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, Beijing 100088, China
| | - Suqin Li
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
| |
Collapse
|
2
|
Guo P, Zhao Z, Li Y, Zhang Y, He T, Hou X, Li S. Co-utilization of iron ore tailings and coal fly ash for porous ceramsite preparation: Optimization, mechanism, and assessment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 348:119273. [PMID: 37832299 DOI: 10.1016/j.jenvman.2023.119273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 09/23/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023]
Abstract
Maximizing the utilization of industrial by-products, such as iron ore tailings (IOTs) and coal fly ash (CFA), is crucial toward sustainable development. This study provides a meticulous insight into the optimization, mechanism, and assessment of the co-utilization of IOTs and CFA for the preparation of porous ceramsite. Micro-CT results revealed that the prepared ceramsite exhibited an exceptional porosity, peaking at 56.98%, with a wide range of pore diameters (3.55-959.10 μm) under optimal conditions (IOTs content at 76%, preheating at 550 °C for 15 min, and sintering at 1177 °C for 14 min), while maintaining good mechanical properties (water adsorption of 1.28%, comprehensive strength of 8.75 MPa, apparent density of 1.37 g/cm3, and bulk density of 0.62 g/cm3). The primary parameters affecting the porosity were identified and ranked as follows: sintering temperature > IOTs content > sintering time. The formation and growth of pores could be attributed to the equilibrium relationship between the liquid-phase surface tension and the gas expansion force, accompanied by pore wall thinning and pore merging. Notably, the prepared ceramsite is both ecologically feasible and economically rewarding, boasting a profit margin of 9.47 $/ton. The comprehensive life cycle assessment (LCA) conducted further highlights the potential of its large-scale implementation for promoting sustainable development. This study provides an innovative strategy for the co-utilization of IOTs and CFA, with advantages such as cost-effectiveness, ecological feasibility and scalability of production.
Collapse
Affiliation(s)
- Penghui Guo
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Zekun Zhao
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Yongkui Li
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Yabin Zhang
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Tao He
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Xinmei Hou
- Institute for Carbon Neutrality, University of Science and Technology Beijing, Beijing, 100083, China; Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Suqin Li
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
| |
Collapse
|