Preparation of Metallic Iron Powder from Pyrite Cinder by Carbothermic Reduction and Magnetic Separation

Abstract

Abstract:The reduction and magnetic separation procedure of pyrite cinder in the presence of a borax additive was performed for the preparation of reduced powder. The effects of borax dosage, reduction temperature, reduction time and grinding fineness were investigated. The results show that when pyrite cinder briquettes with 5% borax were pre-oxidized at 1050˝C for 10 min, and reduced at 1050˝C for 80 min, with the grinding fineness (<0.44 mm) passing 81%, the iron recovery was 91.71% and the iron grade of the magnetic concentrate was 92.98%. In addition, the microstructures of the products were analyzed by optical microscope, scanning electron microscope (SEM), and mineralography, and the products were also studied by the X-ray powder diffraction technique (XRD) to investigate the mechanism; the results show that the borax additive was approved as a good additive to improve the separation of iron and gangue.

Recovery of iron from red mud by high-temperature reduction of carbon-bearing briquettes

“…This can be attributed to the presence of Na 2 O during the reduction roasting, which could promote the transformation of Fe 3+ to Fe 0 , improving the reduction of iron oxides (Chun et al, 2014). On the other hand, sodium borate also creates more lattice defects in metallic iron, thus promoting recrystallization of the metallic iron (Long et al, 2016), which leads to the growth and interconnection of metallic iron grains, resulting in the high iron grade. However, the liquid phase content increased in the presence of the low-melting-point additive (sodium borate).…”

“…The reduced briquettes were ground to 90% passing 0.074 mm in a cone ball mill (model XMQ240×90 from Wuhan Rock Crush & Grind Equipment Manufacture Co. Ltd). Magnetic separation was performed on the powdered briquettes using a Davis tube (model XCGS-73) at a magnetic intensity of 0.08 T (Long et al, 2016).…”

“…During reduction roasting, iron oxides are reduced to metallic iron, which could be upgraded by magnetic separation. Previous research reported that the sodium borate is an effective additive to improve the reduction of iron oxides and the growth of the metallic iron grains (Long et al, 2016). Therefore, sodium borate was employed as an additive in this investigation.…”

“…In recent years, direct reduction and magnetic separation technology has been developed to treat iron-bearing wastes such as copper and chromium slags, pyrite cinder, and red mud (Long et al, , 2016Chun, Long, and Li et al, 2015;Guo et al, 2016). During reduction roasting, iron oxides are reduced to metallic iron, which could be upgraded by magnetic separation.…”

Preparing Ferro-Nickel Alloy from Low-Grade Laterite Nickel Ore Based on Metallized Reduction–Magnetic Separation

“…At last, after reduction, the reduction product was quenched in water and was ground into powder sample. The powder sample was separated by a DTCXG-ZN50 magnetic tube at a magnetic flux density of 50 mT [31]. The magnetic product obtained after separation is ferro-nickel alloy.…”