Preparation Of Electrochemical Materials From The Precipitation And Flotation Sludge Of Copper-containing Wastewater And Performance Research

Heavy metal pollution in water environment has become an increasingly serious problem,and it is of great significance to the research on the efficient and high-value treatment of heavy metal sludge generated in the treatment process.Heavy metal sludge is a kind of hazardous solid waste that threatens the balance of ecosystem and human health.Due to its high water content and poor form stability,traditional solidification/stabilization,sanitary landfill and other disposal technologies have been unable to meet the requirements of comprehensive utilization of resources,and it is easy to cause secondary pollution.Therefore,it is particularly necessary to explore and develop green and sustainable high-value materialized treatment methods for heavy metal sludge.This research was based on the process of purification and separation of copper-containing simulated wastewater by precipitation flotation method,a series of copper ferrite composite materials were synthesized by roasting at high temperature,taking the heavy metal sludge produced after purification and separation of copper containing wastewater by precipitation flotation as the research object.The effects of sludge composition,calcination temperature,binder and metal oxide composite on the microstructure and properties of the materials were investigated,in order to obtain lithium ion battery anode materials with high capacity and stability,and realize the material utilization of sludge with high value.The main research results of this paper are as follows:（1）Preparation of copper ferrite materials from the precipitation and flotation sludge of copper-containing wastewater:the enriched sludge obtained by the purification and separation of copper-containing wastewater by precipitation flotation method had a high content of heavy metal elements and recyclable value.The copper ferrite material was synthesized by the high-temperature roasting method.The copper ferrite particles presented a spherical polyhedron morphology with uniform particle size distribution and good dispersibility,and the particle size was about 80 nm.At the current density of 0.1 A/g,copper ferrite as the negative electrode material had a first discharge capacity of 1102.7 m Ah/g.After 100 cycles,the capacity remained at 277.2m Ah/g.Copper ferrite was an electrochemical material with development potential,which had good cycle performance and cycle stability.（2）Research on the optimization of the organic components of precipitation flotation sludge,roasting temperature and electrode preparation process:the influence of three important factors,such as sludge organic components,roasting temperature and binder on the electrochemical performance of copper ferrite anode material was clarified.The surfactant component in the sludge component affected the morphology and structural characteristics of the material.The material CFO-D calcined with the cationic surfactant DTAB as the precursor component had the largest specific surface area（17.4 m²/g）and the smallest particle size（17.4 nm）,which was beneficial to buffer the volume caused by circulation.The roasting temperature affected the crystal composition and structural characteristics of the material.When the roasting temperature was low,the crystallinity of the material was low,and the structural stability was poor,and the electrode was broken due to the volume expansion during the charge and discharge process,resulting in poor electrochemical stability;when the roasting temperature was too high,the particles of the material accumulated and the material pores were small,The specific surface area was correspondingly small,which hindered the deintercalation reaction of Li⁺,thereby reducing the electrochemical performance.The influence of the binder on the electrochemical performance of the battery was mainly reflected in the play of its bonding effect.The binder PAA inhibited the agglomeration of Li₂O and stabilized the structure of the electrode material,so that the electrode exhibited excellent electrochemical performance.（3）The Preparation of CuFe₂O₄/Cu O and CuFe₂O₄/Fe₂O₃ composite materials were by means of changing the content of copper and iron elements in the precipitation flotation sludge and adjusting the process parameters for improving the electrochemical performance of copper ferrite anode materials.The materials had uniform particle size and good dispersion.Compared with the single copper ferrite,CuFe₂O₄/Fe₂O₃ had good electrochemical performance thanks to the synergistic effect of the two metal oxides.The initial charge/discharge specific capacity was 765.3/1152.5 m Ah/g.After 100 charge-discharge cycles,the specific discharge capacity stabilized at 314m Ah/g.This research provided a new way for the resource utilization of heavy metal sludge,and also provided new ideas and technical reference for the research and application of sludge in other fields.