Herein, we developed a facile method for the synthesis of battery-grade ferric phosphate (FePO 4 ·2H 2 O) using high-pressure hydrolyzed precipitates of cobalt–iron alloy acid solution.
Does iron phosphate meet the quality requirements of battery precursor?
Moreover, all the parameters of the synthesized iron phosphate meet the quality requirements of battery precursor. As the most commonly-used nonferrous metals all over the world, the annual output of aluminium is over 60 million tons, over a half of which comes from China (Xue et al. 2022; Yu et al. 2021).
Which phosphoric acid is used to prepare a stripping agent?
Diammonium hydrogen phosphate ( (NH 4) 2 HPO 4, Sinopharm) and phosphoric acid (H 3 PO 4, 65%, Sinopharm) were used to prepare the stripping agent, and ferric chloride (FeCl 3 ·6H 2 O, Sinopharm) was used to supplement the Fe 3+ in the stripping solution.
Can iron phosphate be used to produce lifeo 4 cathode material?
Importantly, iron phosphate is the raw material for producing LiFeO 4 cathode material, which is usually synthesized by using ferric salts or metallic iron with high purity as the iron source (Zhang et al. 2016). If the iron in bauxite residue can be used to produce iron phosphate, it will significantly improve the benefit of the recycling process.
What is the optimal condition for synthesis of FEPO 4 2H 2 O?
The optimal condition for the synthesis of FePO 4 ·2H 2 O using the stripping solution was determined as: reaction pH of 0.8, reaction temperature of 90°C, Fe/P ratio of 1, and reaction time of 24 h. XRD result showed that the synthesized FePO 4 ·2H 2 O was well-crystallized and perfectly matched with the characteristic peaks of FePO 4 ·2H 2 O.
The theoretical contents of Fe and P in FePO 4 ·2H 2 O are 29.89% and 16.58%, respectively, which is close to the compositions of the precipitate generated under the pH of 0.8. Therefore, the pH was selected as 0.8 in consideration of the precipitation efficiency and the quality of the products.
What is the composition of the Stripping Solution after phase separation?
The stripping solution was obtained after phase separation, and the compositions are presented in Table 1, suggesting that the stripping solution was rich in Fe and P, while the concentrations of other impurities were extremely low. Procedure of using the iron from bauxite residue to produce battery grade iron phosphate