Iron and lithium were recovered from the cathode material of spent lithium iron phosphate battery using choline chloride,ascorbic acid,and ethylene glycol as a ternary deep eutectic solvent.The effects of the molar ratio of choline chloride/ascorbic acid/ethylene glycol,liquid volume to solid mass ratio,reaction temperature and time on the leaching rate of iron and lithium were investigated.The leaching mechanism was discussed through kinetic analysis and SEM characterization.The results show that under the optimal leaching conditions of choline chloride/ascorbic acid/ethylene glycol molar ratio of 1∶1∶3,liquid volume to solid mass ratio of 0.1 mL/1 mg,reaction temperature of 80 ℃ and reaction time of 1 h,the leaching rates of lithium and iron can reach 96% and 98%,respectively.The leaching process is mainly controlled by chemical reactions.The method is efficient and environmentally friendly,and can recover iron and lithium from spent lithium iron phosphate batteries.

The recovery of valuable components manganese and lithium from retired lithium manganese oxide batteries by carbon-thermal reduction—acid leaching combined recovery process was studied.The mixed powder of lithium manganese oxide and graphite was roasted by carbon thermal reduction,and the roasted products were characterized by XRD,XRF,SEM,TG-DTA and other technologies.The results show that the best effect is achieved by roasting at 650 ℃ for 180 min,and the lithium manganese oxide in the roasted product is completely converted into manganese monoxide and lithium carbonate.The lithium carbonate in the sample powder can be extracted by water leaching,and the leaching rate of lithium carbonate is 86.15%.Manganese ions are extracted by acid leaching of sulfuric acid.Under the acid leaching conditions of acid leaching concentration of 3.5 mol/L,acid leaching temperature of 60 ℃,acid leaching time of 3 h,and liquid volume to solid mass ratio of 8/1,the highest leaching rate of manganese ions is 88%.The method can achieve the purpose of synchronous and efficient recovery of manganese and lithium from cathode materials,and has certain application value.

Address to the issue of high fluorine content in the flotation concentrate of a super-large Beryllianite-type uranium-beryllium co-associated ore in Xinjiang,the mineral and elemental composition,as well as the mineral dissemination characteristics were studied.Flotation process of "floating fluorite first and then beryllium" was adopted for flotation.Grinding fineness and flotation reagent system were optimized through systematic flotation condition tests. The results show that for the raw ore with a beryllium grade of 0.435% and a grinding finness of -325 mesh accounting for 93%,under the conditions of 1.5 kg/t for sodium silicate in roughing,2 kg/t for NaOH,700 g/t for oxidized paraffin soap in roughing,and 500 g/t for swept oxidized paraffin soap in scavenging,The technical indicators of flotation with beryllium grade of 3.36% and recovery rate of 81.99% are obtained. The process can achieve effective enrichment of beryllium minerals.

Preparation of alumina from fly ash by hydrochloric acid method is one of the processes with significant industrial application potential.Therefore,studying the ionic structure in acid leaching solution of fly ash is of great significance for iron removal process in the method.The ionic structure of the AlCl₃-FeCl₃-FeCl₂-HCl-H₂O system in hydrochloric acid leaching solution of fly ash at pH values of 1.0,1.5,and 2.0 was investigated by combining thermodynamic calculation,quantum chemical calculation,and Raman spectroscopy. The results show that at pH = 1.0,the main forms of Fe and Al complex ions in the system are [FeCl]⁺,[FeCl₂]⁺ and [AlCl]²⁺;when the pH rises to 1.5 and 2.0,[FeCl]⁺,[FeCl₂]⁺ and [AlCl]²⁺ transform into hydrolysis products such as [FeOH]⁺,[FeOH]²⁺ and [AlOH]²⁺ with hydroxyl ligands.The wave function analysis results indicate that at low pH,due to the high concentration of chloride ions,the chloride complexes are more stable.As the pH increases,the concentration of hydroxide ions increases,and the formation of high-coordination hydroxyl complexes becomes easier due to their higher metal-oxygen bond order and lower Gibbs free energy.

Aiming at the problems of high sulfur content and difficult utilization of high sulfur bauxite,the alkaline leaching desulfurization process of high sulfur bauxite was studied.The effects of alkali mass concentration,liquid volume to solid mass ratio,leaching temperature and time on the desulfurization effect were investigated,and the reaction kinetics were analyzed.The results show that under the conditions of base concentration of 180 g/L,liquid volume to solid mass ratio of 8 L/1 kg,leaching temperature of 160 ℃ and leaching time of 5 h,the bauxite sulfur mass fraction after desulphurization is 0.42%.The desulfurization process is controlled by reaction-internal diffusion,and the apparent activation energy is 18.23 kJ/mol.The method can effectively reduce the sulfur content in high sulfur bauxite and is beneficial to the wide utilization of high sulfur bauxite.

Extraction of copper from refractory copper oxide ore using a roasting—acid leaching process was investigated.The effects of roasting and leaching conditions on the copper leaching rate were examined. The results show that under the optimal conditions of -200 mesh grinding fineness of 70%,roasting temperature of 850 ℃,roasting time of 1 h,coal addition of 8%,liquid volume to solid mass ratio of 2/1,H₂SO₄ concentration of 15%,leaching temperature of 60 ℃ and leaching time of 3 h,the copper leaching rate can reache 91.03%.The process is demonstrated to be economically efficient for extracting copper from refractory copper oxide ore and is considered to have potential for broader application.

Extraction and separation of valuable elements from the positive leaching solution of spent lithium-ion batteries by β-diketone/phosphate extraction system was studied.The optimal conditions for the extraction and separation of cobalt,nickel,manganese,and lithium were determined through equilibrium extraction.The results show that the β-diketone/phosphate extraction system can effectively separate cobalt,nickel,manganese,and lithium from the positive leaching solution of spent lithium-ion batteries by controlling the kinetics.Under optimized conditions,the extraction rate of cobalt,nickel,and manganese can reach 99%,and the yield of lithium can reach more than 95%.The method realizes the separation and recovery of cobalt,nickel,manganese and lithium by a single extraction system,which can provide a new process route for the recovery of waste ternary lithium batteries.

In order to solve the problem of real-time and accurate parameter optimization in hydrometallurgical equipment operation,an optimization setting compensation method based on real-time data acquisition was proposed by combining the improved POPOA method and the improved JITL online learning method.The results show that compared with the traditional method,the retraining time of the modified JITL method is significantly reduced,the optimization rate is significantly increased,and the energy consumption is significantly reduced.The improved POPOA method significantly improves the performance of real-time data processing,and the processing time is about 40% shorter than that of the traditional method.The improved POPOA method reduces the load rate of the system significantly compared with the traditional method when the multi-task is running concurrently.This method can effectively improve the accuracy of operation performance evaluation,the real-time response ability of the system,and the generalization ability of the model,and reduce energy consumption and operation cost,so it has a certain application prospect.

Preparation of a novel imidazole-based functional resin using polystyrene-divinylbenzene copolymer as the support by chloromethylation reaction and imidazole modification was studied. Adsorption properties and selectivity for uranium by the resin from acidic waste solution were systematically investigated. The results show that the equilibrium adsorption capacity of imidazole-based functional resin is 58 mg/g for uranium containing acidic solution with pH=5 and uranium mass concentration of 90 mg/L. Additionally, the resin has good tolerance to nitrate and chloride ions and high adsorption selectivity for uranium. When the mass concentrations of nitrate and chloride are 20 g/L and 5 g/L, respectively, the uranium adsorption capacity can also reach 57 mg/g. When the mass concentrations of uranium and interfering ions in the solution were both 90 mg/L, the adsorption capacity of imidazole-based functional resin for uranium can reach 44 mg/g, while the adsorption capacity of any single interfering ion (A1³⁺, Ca²⁺, Mg²⁺, Zn²⁺, Mn²⁺, K⁺, Na⁺) is less than 5.4 mg/g. Furthermore, 0.5 mol/L HNO₃ is used as desorption, the desorption rate is 99.83%.When the imidazole-based functional resin is used to adsorb the actual uranium-containing acid waste liquid from a mine, the adsorption capacity of uranium is 40.2 mg/g, which is superior to that of common 201×7 anion exchange resin.

Solvent extraction is one of the main methods for rare earth separation and purification, but emulsification often occurs in industrial production due to improper control of process conditions. In order to solve the problem, the extraction of rare earth with the surfactant Span 80 as the regulator, P507 as the extractant and kerosene as the diluent was studied. The effects of aqueous pH, stirring speed and water-oil phase ratio on the extraction rate of Er³⁺ and the mass concentration of oil in the raffinate were investigated, and the process parameters were optimized by response surface method. The optimization results show that under the optimal conditions of aqueous pH=3.5, stirring speed of 130 r/min and water-oil phase ratio of 4∶1 for 5 min, the extraction rate of Er³⁺ can reach 95.42%, and the oil concentration in the raffinate is only 1.68 mg/L. The predicted value is in good agreement with the experimental results. The addition of Span 80 can effectively prevent emulsification, and the regulation effect is obvious.