Article ID Journal Published Year Pages File Type
214002 International Journal of Mineral Processing 2014 9 Pages PDF
Abstract

•We characterise LD slag sample by different analytical techniques.•We examine the reactivity of LD slag.•Soft grinding of LD slag avoids the overproduction of fine particles.•High grade iron compounds are obtained by dry and wet magnetic separations.

A representative sample of LD slag provided from French steel industry was treated by different physical separation techniques especially used in mineral processing. The results of characterisation study show that the LD slag may contain up to 35% of iron compounds. The X-ray diffraction reveals the presence of the following crystallized mineral phases: CaO, MgO, Al2O3, SiO2, MnO, and P2O5. Larnite (Ca2SiO4), di-calcium aluminoferrite (brownmillerite: Ca2Fe2 − xAlxO5 with x = 0.6) and a solid solution (Fe, Mn, Mg)O structurally close to the wüstite (FeO) and some residual lime (CaO).The results of grinding tests show that the manner of grinding is very important. Soft Grinding (SG) or sequential grinding is most suitable to reduce the particle size of LD slag avoiding the overproduction of fine particles, which hinder the effectiveness of magnetic separation techniques. The combination of Low and High Intensity Magnetic Separation (LIMS and HIMS) of ground LD slag at 63 μm in wet process may recover ferromagnetic particles (iron oxides) at LIMS and paramagnetic particles at HIMS, while the non-magnetic fraction contains mostly calcium silicates.From this investigation, two flow-sheets of treatment of LD slag are suggested to recover high grade iron material for recycling in metallurgical processes. Calcium and silicon oxide rich product will be directed to the cement industry.

Related Topics
Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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