Performance evaluation of acid mist reduction techniques in copper electrowinning

The effectiveness of various acid mist suppression techniques has been analysed in the present work. The two important factors that influenced the performance of a floating barrier were its coverage of the solution's surface area and its height above the solution line. When comparing single layered floating barriers, spheres reduced acid mist the most due to their higher buoyancy and higher coverage of the solution surface. In general, barriers made of high density polyethylene were 3.4% more effective in reducing acid mist than those made of polypropylene due to their lower density which enabled them to be more buoyant in the solution and intercept acid mist more effectively.Acid mist was reduced noticeably with the addition of FC-1100 (a chemical reagent widely used to suppress acid mist) to the solution up to 30 ppm. Further addition of FC-1100 made much less difference in the suppression of acid mist. When FC-1100 was used in combination with floating barriers (such as spheres), the reduction in acid mist improved by an average of 29% in comparison to the use of FC-1100 alone.

► Material type and shape of a floating barrier strongly influence its performance.
► Acid mist is increased by 59%, on average, when current density is doubled.
► Use of FC-1100 alone cannot lower acid mist concentration to an acceptable level.
► The combined use of FC-1100 and spheres can reduce acid mist by 91%–98%.