Abstract:Lead and zinc smelting is prone to producing high acid, high halogen, and high thallium contaminated acids. Conventional treatment methods require a large amount of lime and sodium sulfide, resulting in a large amount of hazardous waste that is difficult to treat in the future. This article proposes the process of “oxidation-resin adsorption-segmented neutralization” to treat high thallium contaminated acids, and based on this method, the effects of different oxidants and adsorption forms on resin adsorption of thallium were investigated. Industrial validation was conducted, and the following conclusions were obtained: during the oxidation stage, potassium permanganate had the best effect, considering the cost, hydrogen peroxide was used for industrial production oxidation; dynamic adsorption is superior to static adsorption, and the continuous nature of dynamic adsorption in treating wastewater is beneficial for industrial applications; the anion exchange resin used in the experiment has a good adsorption effect on trivalent thallium, with a dynamic average adsorption efficiency of 89.07%. It has an adsorption effect on cadmium, with a dynamic average adsorption efficiency of 50.66%. It does not have adsorption properties on lead, zinc, and arsenic elements; the content of thallium and arsenic in the treated wastewater can reach stably. The discharge standards of 5μg/L and 0.3mg/L indicate that the thallium-content in the gypsum slag and neutralization slag produced by segmented neutralization is less than 20g/t, and they are not classified as sludge containing thallium. This method not only enriches thallium elements, but also improves the quality of gypsum slag, which is conducive to the utilization of gypsum slag resources and the reduction of thallium containing sludge. In addition, the resin can be regenerated and recycled, saving the cost of acid treatment. It has the promotion value in the field of high- halogen acid wastewater treatment in the lead zinc industry.
