Effect of post-precipitation conditions on surface properties of colloidal metal sulphide precipitates

Effect of solution chemistry on particle characteristics during metal sulfide precipitation

“…Thus, the degree of supersaturation created during copper sulfide precipitation is naturally higher than that of a zinc sulfide system at similar reagent concentrations. While this would appear to account for the observed differences, results from previous studies by Mokone et al [26] showed that a substantial change in supersaturation during metal sulfide precipitation had a negligible effect on the particle size of the final product produced during metal sulfide precipitation. This was due to the fact that even at reagent concentrations below 0.1 mM the supersaturation was still in the region dominated by primary nucleation.…”

“…The zeta potential measurements were carried out using the dynamic light backscattering technique (Malvern Zetasizer, Model Nano-ZS). The effect of ionic strength and suspension pH on the zeta potential of the particles was established in a separate study [17]. The results showed that pH had a significant effect on the zeta potential of the particles while the change in ionic strength of the solution, due to a change in the concentration of background electrolyte (1-100 mM KCl), was found to have a negligible effect on zeta potential.…”

Determination of Size Distribution of Precipitation Aggregates Using Non-Invasive Microscopy and Semiautomated Image Processing and Analysis

“…These processes must accommodate a subsequent solid-liquid separation stage (i.e., thickeners and/or filters) to remove the solids generated from the solution. The characteristics of these precipitates (colloidal behavior and fine particles) determine the kind of thickeners, large filter size and rigorous operational control required to prevent a high content of suspended solids in the recovered solutions [6][7][8][9]. Particularly, the copper sulfide precipitation process from acid mine drainage and cyanide solutions is very attractive, owing to its capacity to recover valuable by-products from wastewaters (in the case of AMD) and gold mining (in the case of cyanide solutions).…”

“…An appropriate characterization of the precipitates size is crucial for the selection and design of an adequate separation process. In this context, there are some studies that characterize the precipitates formed in sulfidization processes for treating AMD [6,7] and cyanide solutions [9,10]. These studies determined the aggregate characteristics from metal sulfide precipitates and the dependence of pH and sulfide dosage (chemical solution characteristics) on aggregate size.…”

Surface cellulose modification with 2-aminomethylpyridine for copper, cobalt, nickel and zinc removal from aqueous solution

“…Therefore, these concerns are part of an organized society that is worried about the welfare of the community and any material is welcome to apply for such applications 1,6 . Although sorption is the most frequently used method, due to its low cost and possible support reuse, among other factors, other methods have been used for cation removal from aquatic environments, such as ion exchange 39,40 , electrodeposition 41,42 , precipitation 43,44 , coagulation and flocculation 45,46 , among others. The present investigation deals with chemically modified cellulose, after incorporating the 2-aminomethylpyridine moiety as a pendant functional chain, which is covalently bound to the polymeric framework.…”