Investigating the reduction of toxicity of the tailings obtained from the processing unit of zinc extraction by solvent extraction method

Subject Areas : The Application of Chemistry in Environment

Hamid Rahati Asiabar ¹ , Seyed Mehdi Barqai ² , Roya MafigholamI ³

1 - Environmental pollution, Islamic Azad University, Tehran West Branch, Tehran, Iran
2 - Environmental pollution, Islamic Azad University, Tehran West Branch, Tehran, Iran
3 - Islamic Azad University, Tehran West Branch, Tehran, Iran

Received: 2023-07-23 Accepted : 2023-10-15 Published : 2023-08-23

Keywords: Zinc, Extraction, Solvent, industrial wastes,

Abstract :

In this research, the ability of solvent extraction to recover zinc from Zanjan Zn extraction unit waste samples has been investigated. This cake contained 180080, 26840, 141040 and 254090 ppm of sulfur, nickel, cadmium and zinc, respectively. Zinc extraction was performed using Cyanex 272 organic solvent. The investigated variables included pH (in the range of 0 to 1.5), time (in the range of 1 to 6 hours), temperature (60 to 80 °C) and the ratio of solids to solution (10 to 30%). Experiments were designed in Design-Expert software version 7 and using central composite design (CCD). pH was the most influential parameter and temperature was the least important parameter. The highest efficiency was measured with 100% at pH 0, temperature 80°C, ratio of solids to solution 30% and time 6 hours. The lowest zinc removal efficiency with 76.6% occurred at pH 1.5, temperature 60 and ratio of solids to solution 10% and time 3.5 hours. Considering the average zinc removal efficiency of 89.10%, the combination of using Cyanex 272 solvent and pH is a suitable method for extracting zinc from cold cake waste and this method has a high performance.