An Innovative Method to Increase Vanadium Extraction from Vanadium Slag by Increasing the Porosity of Roasted Pellet

Abstract

Vanadium extraction from vanadium slag is significantly increased using only NaOH‐added pellet roasting to replace the traditional powder roasting previously. To solve some issues relevant to pellet holes, an innovation process to increase vanadium extraction from vanadium slag by increasing the porosity of roasted pellet is proposed presently. For the pellet added only with Na2CO3 and roasted at 800 °C for 2 h, the melting point of Na2CO3, the pellet porosity, and the vanadium extraction are 851 °C, 6.3%, and 74%, respectively. For the roasted pellet with an optimal NaOH–Na2CO3 additive having a mole ratio of NaOH/(NaOH + Na2CO3) of 0.9, the melting point of additive, the pellet porosity, and the vanadium extraction are 300 °C, 29.6%, and 98.7%, respectively. It is confirmed that the vanadium extraction is proportional to the pellet porosity, maximum of which can be attained by optimizing mole ratio of NaOH to Na2CO3. Both the low melting point and the large alkaline of added NaOH–Na2CO3 mixture are the two possible reasons resulting in the formation of pellet holes.

Consolidation and reduction behaviour of pellets with sea sand vanadium titanomagnetite: a microscopic interpretation of macroscopic properties

“…The size of the porosity affects the compressive strength and reduction properties of the pellet [24][25][26]. The porosity of the pellet was calculated by Equation ( 4).…”

From vanadium slag to multi-cation-intercalated V2O5·nH2O: low-cost direct synthesis and high-performance aqueous battery application

“…1) for aqueous zinc-ion batteries (AZIBs). This strategy to prepare the M x VO cathode offers several merits, which are as follows: (i) compared with the conventional alkaline roasting technology, [23][24][25] the roasting process not only reduces the discharge of harmful exhaust gas and high content saline wastewater but also avoids the agglomeration of slag, which is benecial for the oxidation and the recovery of vanadium; (ii) unlike the conventional tedious vanadium precipitation procedure, the acidication-hydrothermal process can effectively utilize the unexpected ions (such as iron, magnesium, and titanium) to prepare M x VO microower cathode for AZIBs; and (iii) M x VO delivers a superior rate capability (203 mA h g À1 at 100 A g À1 ) and long-term cycling performance (317 mA h g À1 aer 4000 cycles at 20 A g À1 ), and when tested at À20 C, both coin-type batteries and pouch cells demonstrate excellent zinc storage capability (e.g., a discharge capacity of 118 mA h g À1 can be achieved at 50 A g À1 and a capacity of 230 mA h g À1 can be retained aer 1000 cycles at 10 A g À1 in coin-type batteries). As per our knowledge, this is the rst time that a vanadium-based solid waste from industrial production is utilized for energy storage-related application, and the achieved electrochemical performance of M x VO is outstanding among all the reported AZIB cathodes.…”

A Novel Method of Recovery Vanadium from Vanadium Slag through CaO2‐Briquetting Roasting Process

“…The problem of the accumulation of V‐slag powders causes another fatal problem, i.e., hypoxia of the inside V‐slag. To solve the accumulation problem, Fang [ 10 ] proposed an idea of mixing V‐slag with sodium salts (NaOH + Na 2 CO 3 ) powders and briquetting into pellets. The V extraction generally showed a proportional relationship with the pellet porosity.…”

“…[ 16 ] Herein, the authors believe that oxygen diffusion into V‐slag is another parameter that should be considered and optimized in addition to the additive content, roasting temperature, and time. Previous studies [ 10–12 ] attempted to promote the diffusion of oxygen from the outside into the interior of V‐slag pile, while this article attempts to change the way of thinking to increase the oxidation rate through inducing the oxygen transport from the interior into the outside of V‐slag pile. CaO 2 is mixed with V‐slag powders and subjected to briquetting and roasting; oxygen decomposes from CaO 2 and oxidizes low‐valent V along the way of spilling out, and increases the partial pressure of oxygen after reaching the atmosphere.…”