Purification of a Nigerian Wolframite Ore for Improved Industrial Applications

Low-Energy Feasibility for Leaching an Indigenous Scheelite Ore for Industrial Applications

“…For example, at 2 h of contact time, the dissolution reaction yielded 38.4% using 2.5 mol/L HCl solution, whereas the dissolution rate was 16.1% with 0.1 mol/L HCl solutions. This affirms that the concentration of hydrochloric acid has a considerable effect on the dissolution of scheelite ore which can be attributed to the presence of hydrogen [H + ] ion from hydrochloric acid solution [7].…”

“…This was followed by adding 10 g/L of the < 75 µm scheelite smallest particle size to the reactor and the contents were thoroughly stirred. After a specific duration, the resultant solution was filtered, water-washed, and oven-dried at 40 °C for 24 h. The fraction of ore reacted in the leachant was calculated from the difference between the mass of the reacted and unreacted at various contact times after respective drying [7,23,24]. For a better understanding of the nature of the unreacted species, the residual product at optimal leaching conditions (2.5 mol/L HCl, 70 °C, < 75 µm, 120 min) was accordingly analyzed by X-ray diffraction (XRD) using PHILIP PW 1800 X-ray diffraction with Cu Kα 1 (0.154 nm) radiation graduated at 40 kV and 55 mA, Scanning electron microscopy (SEM) with NanoSEM 230, and Energy dispersive spectroscopy (EDS) with an oxford X-max EDS detector using INCA software, respectively.…”

“…For a better understanding of the nature of the unreacted species, the residual product at optimal leaching conditions (2.5 mol/L HCl, 70 °C, < 75 µm, 120 min) was accordingly analyzed by X-ray diffraction (XRD) using PHILIP PW 1800 X-ray diffraction with Cu Kα 1 (0.154 nm) radiation graduated at 40 kV and 55 mA, Scanning electron microscopy (SEM) with NanoSEM 230, and Energy dispersive spectroscopy (EDS) with an oxford X-max EDS detector using INCA software, respectively. Also, the dissolution kinetics mechanism for the scheelite ore dissolution was determined by appropriate shrinking core models (SCM) [7,23,25].…”

“…However, tungsten as a strategic and industrial metal due to its excellent properties such as corrosion resistance, hardness, high modulus of elasticity, highest melting point, armaments, and tensile strength as well as vapor pressure makes its wide uses possible as a catalyst, cemented carbide, alloys and steels, lighting technology, electronics, X-ray tubes, and photo/electro-chromic usages [7][8][9][10]. According to the United States Geological Survey (USGS) statistical data in 2018, the world tungsten reserves including scheelite, wolframite, and its varieties are estimated to be around 3.3 million tons [11].…”

“…According to the United States Geological Survey (USGS) statistical data in 2018, the world tungsten reserves including scheelite, wolframite, and its varieties are estimated to be around 3.3 million tons [11]. In Nigeria, for example, the wolframite ore deposits contain admixtures of scheelite and stolzite, which could be easily treated and beneficiated to obtain high-grade tungsten compounds of industrial utilities [7]. Nowadays, scheelite is the most common tungsten compounds with varied colors ranging from pale white to brown-orange, though dominated with blue coloration under UV, and often changes with increasing molybdenum content [7,12].…”