Synthesis of metaettringite from blast furnace slag and evaluation of its boron adsorption ability
- PDF / 1,050,740 Bytes
- 6 Pages / 595.276 x 790.866 pts Page_size
- 81 Downloads / 184 Views
RESEARCH ARTICLE
Synthesis of metaettringite from blast furnace slag and evaluation of its boron adsorption ability Shie Yamaguchi 1 & Teruhisa Hongo 1 Received: 21 May 2020 / Accepted: 27 September 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Blast furnace slag (BFS) is generated as a by-product in the ironmaking process, and hence, the development of a recycling system for BFS waste is important. In this study, the calcium component of BFS obtained from a steel company in Japan was successfully used as raw material of the synthesis of metaettringite. Metaettringite has been recently considered for as an adsorbent for boron, which is toxic to humans and animals. The BFS used was amorphous, and mainly consisted of CaO, SiO2, Al2O3, and MgO; in particular, it contained 42.82 mass % CaO. The X-ray diffraction pattern and Fourier transform infrared spectrum of the synthesized sample indicated the formation of metaettringite. Field-emission scanning electron microscopy observations revealed its needle-like morphology. The synthesized metaettringite adsorbed 1.189 mg-B/g-adsorbent in 240 min, which was approximately 25 times greater than that achieved using the parent BFS. The metaettringite can reduce the boron concentration to below the uniform effluent standard in industrial wastewater in Japan (16 mg/L). Keywords Blast furnace slag . Recycle . Boron . Adsorbent . Metaettringite . Water treatment
Introduction Blast furnace slag (BFS) is generated as a by-product in the ironmaking process. About 0.25–0.30 ton of BFS is produced for per ton of pig iron. In Japan, 76 million tons of pig iron was produced in 2018, and as a result, 22 million tons of BFS was produced as a by-product (Nippon Slag Association 2019). BFS is obtained by quenching the molten slag from a blast furnace. The quenching method is classified into two methods: slow quenching in air, and rapid quenching in water. In Japan, water-granulated blast furnace slag (WGBFS) accounted for more than 80% of the BFS produced, and amounted to 18.9 million tons in 2018. BFS is generally composed of a complex melt of calcium, silicon, aluminum, magnesium, and etc., in the form of oxides. Among these elements, calcium is particularly abundant in BFS. About 80% of the BFS has been reused for cement and concrete; however, Responsible Editor: Tito Roberto Cadaval Jr * Teruhisa Hongo [email protected] 1
Department of Life & Green Chemistry, Faculty of Engineering, Saitama Institute of Technology, 1690 Fusaiji, Fukaya, Saitama 369-0293, Japan
its reuse is expected to decrease in Japan. Therefore, there is a strong demand for the development of new applications for the slag. Boron is an essential micronutrient for humans and animals, although regular intake has a negative impact on their health. Of concern are reproductive toxicity and the suspected teratogenicity of boron (Liu et al. 2009). In Japan, the uniform effluent standard of boron in industrial wastewater is 16 mg/L. Boron compounds are contained in sewage effluents arisin
Data Loading...
