Removal of Silica and Alumina as Impurities from Low-Grade Iron Ore Using Wet High-Intensity Magnetic Separation and Reverse Flotation

Abstract

This study investigates the removal of silica and alumina as impurities from hematite based low-grade iron ore containing 34.18 mass% iron, 31.10 mass% of silica and 7.65 mass% alumina. Wet high-intensity magnetic separation (WHIMS) and reverse flotation (RF) were investigated. In WHIMS process, 93.08% of iron was recovered with a grade of 53.22 mass% at an optimum magnetic density of 10,000 mT, and pulp density of 2% used the L-4 machine. In RF experiments, optimal results showed 95.95% of iron recovered with 51.64 mass% grade using 1 kg/t of 1% alkaline starch as iron depressant and 1:1 mixture ratio of 0.75 kg/t DAA and NaOL as silica and alumina collectors. The designed multi-stage process involving feeding the concentrate from WHIMS into RF process reduced silica to 2.02 mass%, alumina to 1.04 mass% whilst recovering 81.94% of the iron with 67.27 mass% grade. As a result of this research, a process to produce high quality iron concentrate from hematite based low-grade iron ore with high iron recovery rate was constructed.

Enrichment of Co, Ni, and Mn from Cobalt-rich Ferromanganese Crust by Combining Enhanced Gravity Separation and Reverse Froth Flotation

“…On the other hand, reverse flotation is another type of froth fl otation during which valuable materials are depressed, whereas gangue particles are fl oated [35]. Figure 4 shows the schematic of a fl otation cell, indicating the principle of reverse fl otation.…”

“…During the reverse flotation, 10 g CRFC was dispersed into 230 mL water, giving a solid-liquid ratio of 4.35 wt.%). Then a frother (0.2% methyl isobutyl carbinol, MIBC) and a surfactant (0.12 g/L DAA) were added [35][36]. After pH was adjusted at 4, the slurry was stirred for 5 minutes, and then reverse flotation was performed.…”

Improving Silica Sand Specifications for Making Colorless Glasses by Using Chemical and Physical Methods

“…Iron oxide impurities can be reduced in silica sand by physicochemical methods, such as the attrition process and flotation to clean the surface of particles from iron-bearing minerals [14] and separate iron-rich minerals [15]. Magnetic separation used a wet high-intensity method to recover iron from low-grade ore [16], due to its good separation efficiency compared with gravity separation and dry magnetic separation [17]. Flotation processes using cationic or anionic collectors are considered the most effective technique to separate iron minerals that are aggregated and form weak magnetic particles [18].…”