Recovery of magnetite from FeSO₄·7H₂O waste slag by co-precipitation method with calcium hydroxide as precipitant

Abstract

Proper utilization of the FeSO₄·7H₂O waste slag generated from TiO₂ industry is an urgent need, and Fe₃O₄ particles are currently being widely used in the wastewater flocculation field. In this work, magnetite was recovered from ferrous sulphate by a novel co-precipitation method with calcium hydroxide as the precipitant. Under optimum conditions, the obtained spherical magnetite particles are well crystallized with a Fe₃O₄ purity of 88.78%, but apt to aggregate with a median particle size of 1.83 μm. Magnetic measurement reveals the obtained Fe₃O₄ particles are soft magnetic with a saturation magnetization of 81.73 A·m²/kg. In addition, a highly crystallized gypsum co-product is obtained in blocky or irregular shape. Predictably, this study would provide additional opportunities for future application of low-cost Fe₃O₄ particles in water treatment field.

Keywords

FeSO₄·7H₂O / TiO₂ industry / magnetite / co-precipitation / calcium hydroxide / magnetic seeding flocculation

References

[1] GazquezM J, BolivarJ P, Garcia-TenorioR, VacaF. Physicochemical characterization of raw materials and co-products from the titanium dioxide industry [J]. Journal of Hazardous Materials, 2009, 166(23): 1429-1440

[2] EEC. Council directive 92/112/EEC of 15 December 1992 on procedures for harmonizing the programmes for the reduction and eventual elimination of pollution caused by waste from the titanium dioxide industry [S].

[3] TavaniE L, LacourN A. Making of iron(III) tanning salts from a waste of the titanium recovery by the sulphate process [J]. Materials Chemistry and Physics, 2001, 72(3): 380-386

[4] GuskosN, PapadopoulosG J, LikodimosV, PatapisS, YarmisD, PrzepieraA, PrzepieraK, MajszczykJ, TypekJ, WabiaM, AidinisK, DrazekZ. Photoacoustic, EPR and electrical conductivity investigations of three synthetic mineral pigments: Hematite, goethite and magnetite [J]. Materials Research Bulletin, 2002, 37(6): 1051-1061

[5] LiuZ-c, ZhengY-jie. Micaceous iron oxide prepared from pyrite cinders by hydrothermal method [J]. Journal of Central South University, 2011, 18(1): 89-95

[6] ZhengY-j, LiuZ-cheng. Preparation of monodispersed micaceous iron oxide pigment from pyrite cinders [J]. Powder Technology, 2011, 207(1-3): 335-342

[7] ZhengY-j, GongZ-q, Chenb-z, LiuL-hua. Preparation of solid polyferric sulfate from pyrite cinders and its structure feature [J]. Transactions of Nonferrous Metals Society of China, 2003, 13(3): 690-694

[8] LakshmananR, Rajarao-KuttuvalG. Effective water content reduction in sewage wastewater sludge using magnetic nanoparticles [J]. Bioresource Technology, 2014, 153: 333-339

[9] JiangC, WangR, MaWei. The effect of magnetic nanoparticles on Microcystis aeruginosa removal by a composite coagulant [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2010, 369(1-3): 260-267

[10] LiY-r, WangJ, ZhaoY, LuanZ-kun. Research on magnetic seeding flocculation for arsenic removal by superconducting magnetic separation [J]. Separation and Purification Technology, 2010, 73(2): 264-270

[11] WeiX-c, Viadero-JrR C. Synthesis of magnetite nanoparticles with ferric iron recovered from acid mine drainage: Implications for environmental engineering [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2007, 294(1-3): 280-286

[12] ShenL-z, QiaoY-s, GuoY, MengS-m, YangG-c, WuM-x, ZhaoJ-guo. Facile co-precipitation synthesis of shape-controlled magnetite nanoparticles [J]. Ceramics International, 2014, 40: 1519-1524

[13] NabiyouniG, JulaeeM, GhanbariD, AliabadiP C, SafaieN. Room temperature synthesis and magnetic property studies of Fe₃O₄ nanoparticles prepared by a simple precipitation method [J]. Journal of Industrial and Engineering Chemistry, 2015, 21: 599-603

[14] LinC-c, HoJ-m, WuM-shan. Continuous preparation of Fe₃O₄ nanoparticles using a rotating packed bed: Dependence of size and magnetic property on temperature [J]. Powder Technology, 2015, 274: 441-445

[15] ZhangD-e, TongZ-w, LiS-z, ZhangX-b, YingA-ling. Fabrication and characterization of hollow Fe₃O₄ nanospheres in a microemulsion [J]. Materials Letters, 2008, 62(24): 4053-4055

[16] AlbornozC, JacoboS E. Preparation of a biocompatible magnetic film from an aqueous ferrofluid [J]. Journal of Magnetism and Magnetic Materials, 2006, 305(1): 12-15

[17] MaoB-d, KangZ-h, WangE-b, LianS-y, GaoL, TianC-g, WangC-lei. Synthesis of magnetite octahedrons from iron powders through a mild hydrothermal method [J]. Materials Research Bulletin, 2006, 41(12): 2226-2231

[18] ValenzuelaR, FuentesM C, ParraC, BaezaJ, DuranN, SharmaS K, KnobelM, FreerJ. Influence of stirring velocity on the synthesis of magnetite nanoparticles (Fe₃O₄) by the co-precipitation method [J]. Journal of Alloys and Compounds, 2009, 488(1): 227-231

[19] ŠutkaA, LagzdinaS, JuhnevicaI, JakovlevsD, MaiorvM. Precipitation synthesis of magnetite Fe₃O₄ nanoflakes [J]. Ceramics International, 2014, 40: 11437-11440

[20] ShenL-z, QiaoY-s, GuoY, TanJ-ru. Preparation and formation mechanism of nano-iron oxide black pigment from blast furnace flue dust [J]. Ceramics International, 2013, 39(1): 737-744

[21] AmbashtaR D, SillanpääM. Water purification using magnetic assistance: A review [J]. Journal of Hazardous Materials, 2010, 180(1-3): 38-49

[22] ShenL-z, QiaoY-s, GuoY, TanJ-ru. Preparation of nanometer-sized black iron oxide pigment by recycling of blast furnace flue dust [J]. Journal of Hazardous Materials, 2010, 177(1-3): 495-500

[23] ZhangW-x, LuB, TangH-h, ZhaoJ-x, CaiQ-hai. Reclamation of acid pickling waste: A facile route for preparation of single-phase Fe₃O₄ nanoparticle [J]. Journal of Magnetism and Magnetic Materials, 2015, 381: 401-404

[24] ChenR-f, SongS-s, WeiYu. Study on the formation and phase transformation of 1D nanostructured Fe₃O₄ particles under an external magnetic field [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2012, 395: 137-144

[25] KulkarniS A, SawadhP S, PaleiP K, KokateK K. Effect of synthesis route on the structural, optical and magnetic properties of Fe₃O₄ nanoparticles [J]. Ceramics International, 2014, 40: 1945-1949

[26] HongR Y, LiJ H, LiH Z, DingJ, ZhengY, WeiD G. Synthesis of Fe₃O₄ nanoparticles without inert gas protection used as precursors of magnetic fluids [J]. Journal of Magnetism and Magnetic Materials, 2008, 320(9): 1605-1614