Separation of vanadium and tungsten from synthetic and spent catalyst leach solutions using an ion-exchange resin

Recovery of Low-Concentration Tungsten from Acidic Solution Using D318 Macroporous Resin

Tungsten is a crucial strategic metal that plays a significant role in various fields, such as the defense industry, fine chemicals, and the preparation of new materials. During the practice of numerous tungsten smelting processes, a large amount of acidic wastewater containing low concentrations of WO3 is generated. The adsorption method, known for its simplicity, effectiveness, and ease of operation, represents the most promising approach for tungsten recovery and is vital for the sustainable development of the tungsten industry. In this study, D318 macroporous resin was used as an adsorbent to investigate its effectiveness in adsorbing WO3 from acidic solutions. Static adsorption experiments revealed that the adsorption capacity of D318 resin for WO3 was 683 mg·g-1. Kinetic analysis indicated that the controlling step for the adsorption of WO3 from acidic solutions by D318 resin was intraparticle diffusion. Thermodynamic analysis demonstrated that the adsorption process was endothermic and could occur spontaneously. By fitting the isothermal adsorption equation, it was found that the Langmuir model was more suitable for describing the adsorption process of WO3 on D318 resin in acidic solutions. The results of dynamic adsorption experiments showed that under optimized conditions, the dynamic adsorption capacity for WO3 was 529 mg·g-1; when using NaOH as the desorbent for cyclic desorption, the desorption rate for WO3 was 98.21%. XPS and SEM-EDS testing and analysis confirmed that D318 macroporous resin exhibited excellent adsorption performance for tungsten in acidic solutions.

Synthesis, characterization, and physico-chemical aspects of a new PVC-based quaternary triethanol ammonium chloride anionite for tungsten recovery

The usability of polyvinyl chloride-based quaternary triethanol ammonium chloride anionite (PVC-TEAC) as a potential extractant for tungstate was investigated to recover tungstate from Gabal Qash Amir, Egypt, assaying 70.91% WO3. Structure elucidation for PVC-TEAC anionite was successfully carried out using several techniques. Experimental measurements, such as pH, agitation time, initial tungsten concentration, anionite dose, co-ions, temperature, and eluting agents, have been optimized. It was found that PVC-TEAC anionite has a maximum capacity of 63 mg per gram. From the distribution isotherm modeling, Langmuir's model fits the experimental results better than Freundlich's, with a theoretical value of 61.728 mg g-1. According to kinetic modeling, the first- and second-order modeling may be regarded as a mixed modeling for a successful adsorption system. Thermodynamic prospects reveal that the adsorption process was predicted as an exothermic, spontaneous, and preferable adsorption at low temperatures. Tungsten ions can be eluted from the loaded anionite, by 1M H2SO4 with a 97% efficiency rate. It was found that PVC-TEAC anionite reveals good separation factor (S.F.) towards most of co-ions. A successful Alkali fusion with NaOH flux followed by tungstate recovery by PVC-TEAC anionite is used to obtain a high-purity tungsten oxide concentrate (WO3), with a tungsten content of 78.3% and a purity of 98.75%.