Studies On The Application Of Styrene/Maleic Anhydride Copolymer In Hydrometallurgy And Material Preparation

Styrene/maleic anhydride copolymer（PSMA）has several advantages such as cheap raw material and convenient synthesis method.The ring open products of PSMA are the carboxylic acid functionalized polymer materials,which have a strong coordination with metal ions.A series of PSMA had been synthesized in this paper,and the hydrolysis product of PSMA（HPSMA）was used to enrich and recycle low concentration of Th4+ and RE3+ in rare earth hydrometallurgy process.Lithium and manganese macromolecular complex was prepared by the variance of coordination ability of HPSMA to Li+ and Mn2+.This macromolecular complex can be as a precursor for synthesis of LiMn₂O₄ with good performance in relatively mild conditions.In addition,hydrophobic poly（ionic liquid）s,which used for the enrichment of low concentration of precious metal,were synthesized by PSMA reacted with amino imidazole and then with benzyl chloride.The specific contents of this paper are as follows:1.The introduction part described the general situation and development of adsorption materials,separation metal materials and battery materials in functional materials and reviewed the applications of poly（styrene-co-maleic anhydride）in various scientific field.PSMA both has the hydrophobic phenyl and hydrophilic anhydride groups.Its excellent properties relied on unique arrangement of monomer and ring opening of anhydride.On the basis of summarizing the related literature reports,we elaborated the theoretical basis and feasibility of low concentration metal ions enrichment and separation by using ring-opening products of PMSA in hydrometallurgy process.According to the properties of macromolecule metal complexes with a variety of metal ions in the uniform distribution,macromolecule metal complexes formation from HPSMA was used as a precursor for synthesis of battery material to overcome the problem of the slow diffusion,long preparation time and high energy consumption in solid-phase synthesis.2.The hydrolysis products of poly（styrene-co-maleic anhydride）（HPSMA）enriched low concentration thorium.HPSMA can be preferentially coordinated with thorium to form a cross-linked macromolecular compound in the high concentration of rare earth solution.Taking advantage of this property,we studied on the enrichment low concentration of radioactive Th4+ from the sulfuric acid leaching solutions of bastnaesite.At the optimal adsorption condition,the adsorption percentage of Th4+ was 97.93% and the maximum adsorption capacity was 360.14 mg g-1.The adsorption isotherm data were consistent with the Langmuir model,which confirmed the monolayer coverage mechanism of Th4+ onto the HPSMA surface.The adsorption kinetic data fit pseudo-secondorder model,which suggested a chemical coordination process.Th4+ was efficiently enriched and separated from the solution containing La3+ or Mg2+ by adjusted pH values,and these selectivity coefficients were above 103.High concentration Th4+ solution and undissolved polymer were obtained by inorganic acid.The regenerated HPSMA resin can be utilized repeatedly.3.HPSMA as a high-efficiency adsorbent was used for recovering La3+,Eu3+,Tb3+ and Yb3+ from the simulate industrial emissions of sulfate double salt deposited rare earths.The results indicate that HPSMA had a high enrichment effect on light rare earth La3+,middle rare earth Eu3+,Tb3+ and heavy rare earth Yb3+.The Langmuir model and the pseudo-second-order model were found to fit for the experiment data of all the rare earth ions（RE3+）.The maximum adsorption capacity of this material for La3+,Eu3+,Tb3+ and Yb3+ is 285.79,301.92,305.46 and 336.65 mg g-1,respectively.The adsorption could be conducted in pH 6.0 and the equilibrium was fast established in 30 min.The separation factors of Ca²⁺/ RE3+ and Mg2+/ RE3+ were both higher than 200.The spent adsorbent could be well desorption by inorganic acid and kept above 80 % of adsorption efficiency at the end of the fifth cycle.In addition,we have designed and synthesized chitosan modified poly（styrene-co-maleic anhydride）（HPSMA-CS）,which is used to overcome the problem that the micelle formed with HPSMA and RE3+ was not favorable to sedimentation in alkaline solution.This adsorbent applied for the enrichment of La3+.The adsorption capacity of HPSMA-CS for La3+ was more than 100 mg g-1,which is higher than other solid adsorbent which was reported in literatures.It was found that metal macromolecular compounds showed a good hydrophobicity in the p H value of solution range 1 to 14,reducing the loss of the adsorbent in the adsorption process and the environmental hazards.4.PSMA was opened ring using LiOH solution.Mn2+ can replace parts of Li+ when Mn2+ added in hydrolyzed PSMA,forming Li-Mn macromolecular complexes.The complexes used as a precursor to synthesis of micro-nanocrystalline LiMn₂O₄ by a simple and economical route.In the precursor,Li+ and Mn2+ have uniform mixed on the atomic scale,omitting Li+ and Mn2+ diffusion process in the product of the solid-state reaction.Thus,this route greatly reduces roasting time and the calcination temperature.At three different temperatures,we obtained different LiMn₂O₄ particles in 5 h,which is LMO-500（calcinated at 500 oC）,LMO-600（calcinated at 600 oC）and LMO-700（calcinated at 700 oC）.Their morphologys and structures were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,and Transmission electron microscope（TEM）.Electrochemical studies indicated that the electrochemical performances of LMO-600 are better than business LiMn₂O₄,LMO-500 and LMO-700.The cell’s ability of LMO-600 electrode maintained high capacity after being subjected to fast charge/discharge cycles because the particle size of LMO-600 had shorter diffusion channels than that of LMO-700,and the higher crystallinity of LMO-600 compared to the LMO-500.Compared with the traditional solid phase synthesis method,polymeric precursors method has some advantages such as fast,convenient,low energy consumption and stable product.Moreover,doping indium in products may further improve the cycling stability of the electrode material at elevated temperature and higher current density.5.The design and synthesis of a of poly（ionic liquid）s containing imidazole group,as a new type founctional separation materials,can be enriched low concentration of Au（Ⅲ）from the non-ferrous metal system.The polymer（ionic liquid）s were characterized by elemental analysis,IR,NMR,SEM and XPS before and after loading Au（Ⅲ）.The optimum pH,temperature,time and dose of polymeric ionic liquid are discussed in detail.The results showed that the imidazolium ionic liquid can recover Au（Ⅲ）rapidly from the mixed system because it has a variety of physical and chemical effects on AuCl4–.The maximum adsorption capacity was up to 239.17 mg g-1.A large number of transition metals（Ni2+,Mn2+,Cu2+,Zn2+,Co2+,Cr3+,Fe3+）have little effect on the enrichment of Au（Ⅲ）.This poly（ionic liquid）s is expected to be used for the enrichment and recovery of trace gold in the hydrometallurgy system.The poly（ionic liquid）s loading gold can be eluted and regenerated by thiourea solution,so as to achieve the purpose of recycling.