Action of DETA, dextrin and carbonate on lead-contaminated sphalerite

Lead ions can adsorb on sphalerite and promote flotation in the presence of xanthate. This process, known as accidental activation, is generally undesirable. One method of control is addition of a reagent to depress the lead ion effect. Three reagents, diethylenetriamine (DETA), dextrin, and sodium carbonate, were compared by measuring zeta potential and xanthate adsorption. The order of effectiveness in suppressing xanthate uptake over the conditions tested is dextrin > carbonate > DETA. The depressant action was attributed to a blocking mechanism through formation of surface complexes.