Effect of Calcium Oxide on the Crushing Strength, Reduction, and Smelting Performance of High-Chromium Vanadium–Titanium Magnetite Pellets

Abstract

Abstract:The effect of calcium oxide on the crushing strength, reduction, and smelting performance of high-chromium vanadium-titanium magnetite pellets (HCVTMP) was studied in this work. The main characterization methods of an electronic universal testing machine (EUTM), X-ray fluorescent (XRF), inductively-coupled plasma-atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), and scanning electron microscope-energy disperse spectroscopy (SEM-EDS) were employed. The crushing strength was affected by the mineral phases generated during oxidative baking and the subsequently-formed pellet microstructures owing to CaO addition. The reduction and smelting properties of HCVTMP with different CaO additives were measured and characterized with different softening-melting-dripping indices. Although HCVTMP showed the highest crushing strength with CaO addition of ca. 2 wt %, more CaO addition may be needed to achieve high permeability of the furnace burdens and a good separation condition of the slag and melted iron. In the formation process of the slag and melted iron, it can be determined that CaO could have a relationship with the transformation behavior of Cr, V, and Ti to some extent, with respect to the predominant chemical composition analysis of ICP-AES and XRF. With the microscopic examination, the restraining formation of Ti(C,N) and the promoting formation of CaTiO 3 are in accordance with the improved melting-dripping indices, including the decrease of the maximum external static load and gas permeability, and the increase of the melting-dripping zone and dripping difficulty.

Effect of TiO2 on the Sintering Behavior of Low-Grade Vanadiferous Titanomagnetite Ore

“…Vanadiferous titanomagnetite ore (VTM) provides an important source of iron, and the associated vanadium, titanium, chromium, cobalt, nickel, platinum, and scandium components are of high economic value. The VTM is distributed globally with large reserves, mainly in China's Panzhihua and Chengde regions, exceeding five billion tons [1][2][3][4][5]. However, after years of mining, Chengde's main mining areas have been emptied of high-grade VTM and there is little prospect of finding ore in the periphery of the mine.…”

Modeling and Experimental Study of Ore-Carbon Briquette Reduction under CO–CO2 Atmosphere

“…The use of these briquettes offers advantages, such as a high reduction rate, utilization of non-coking coal, and biochar for producing sponge iron economically. The ore-carbon briquette reduction technology is often used in treating various metallurgical dust and sludge [5][6][7], recovering valuable metals, such as nickel and titanium, from complicated minerals [8][9][10][11], and upgrading refractory iron ores by removing detrimental minerals, such as quartz and alumina [12][13][14]. The reduction of ore-carbon briquettes is usually carried out at the industrial level using rotary hearth furnace (RHF) reduction technology [15].…”

Property Investigations of Low‐Grade Vanadium‐Titanium Magnetite Pellets with Different MgO Contents

“…Vanadium‐titanium magnetite is a vital ironmaking resource, which includes many valuable elements like Fe, Ti, V, Cr, etc . At present, there is a mature technology for the utilization of vanadium‐titanium magnetite with less than 15 wt% titanium dioxide .…”