Lead-Zinc Benefication Wastewater Treatment By CP Adsorbent

With the increasing demand for mineral resources,the output of lead-zinc mines in China has been ranking first in the world.However,the discharge of industrial wastewater generated during the beneficiation of lead-zinc mines is also growing rapidly.The non-compliance discharge of the wastewater not only limits the healthy development of the industry,but also adversely affects people's living environment.CP adsorbent is a kind of porous coal-based material,which is produced after high temperature pyrolysis of coking coal in dry quenching process.It's of high ash content and difficult to use.In this paper,the cheap CP adsorbent is used as adsorbent to remove organic matter and heavy metal ions.The single factor conditions experiment is used to examine the adsorption performance of CP adsorbent.The structure-activity relationship between CP adsorbent and typical pollutants was studied,and the adsorption mechanism was explored.This study provides the theoretical guidance for the application of the CP adsorbent adsorption process to various beneficiation wastewater treatment.The CP was taken from Shandong coking plant and the physicochemical properties of the CP were characterized through XRF and XRD.The results show that CP contains a lot of organic ingredients and less gangue mineral impurities.It is conducive to the subsequent adsorption of characteristic pollutants.The microstructure and pore structure of CP were characterized through SEM and BET.The specific surface area of CP is larger than that of common pulverized coal,and it contains abundant pore structure as high-quality adsorbent.This paper selects the three flotation agents in lead-zinc beneficiation wastewater.butyl xanthate,diethyldithiocarbamate?NA?,and aniline aerofloatas the typical organic pollutants.The impact of adsorbent dosage,adsorption time,temperature and other conditions on removal efficiency were investigated by single factor expriment.Under the optimal experimental conditions that were selected in this experiment,the removal efficiency of xanthate,NA,and aniline aerofloat are 96.93%,81.18%,and82.27%.The adsorption thermodynamics and kinetics indicate that the adsorption bahaviors of three flotation reagents on CP fitted in the Freundlich model.The adsorption process are exothermic and mainly physical adsorption controlled.The adsorption-rates by CP follows the order of aniline aerofloat>xanthate>NA.Pb²⁺and Zn²⁺were selected as the typical heavy metal ions.The impact of adsorbent dosage,adsorption time,and initial concentration on removal efficiency were investigated by single factor experiment.Under the optimal adsorption conditions selected in this experiment,the removal rates of Pb²⁺and Zn²⁺are 87.99%and 81.05%,and the adsorption capacities are 14.08 mg/g and 4.06 mg/g.The adsorption thermodynamics and kinetics show that the adsorption contains physical adsorption and chemical adsorption,and the adsorption process is an endothermic process.There is competitive adsorption between Pb²⁺and Zn²⁺,and the CP preferentially adsorbs Pb²⁺that is mainly determined by the negative charge of the CP surface and the characteristics of the heavy metal ions.In the binary competitive adsorption system of flotation agent-heavy metal ions,xanthate and NA both have a promoting effect on Pb²⁺and Zn²⁺removal,and the higher concentration gets stronger promoting effect.The CP was used to purify the lead-zinc beneficiation wastewater.the removal efficiency of Pb²⁺and Zn²⁺are 98.96%and 46.01%when the initial pH value is neutral and the adsorbent additive amount is 50 g/L.The removal efficiency of COD attains to 63.70%at the pH of 2.