Chitosan microspheres (HTCC) were prepared by hydrothermal method, and Amino-modified chitosan adsorbent (AHTCC) was prepared by epoxidization and amination method to adsorb low concentration uranium in wastewater. The structure, composition and thermal stability of AHTCC were characterized by infrared spectrometer, elemental analyzer and thermogravimetric analyzer, and the adsorption and desorption properties of AHTCC for uranium were investigated. The results show that AHTCC has a good adsorption effect on uranium in solution at pH=5~8. Under the condition of equilibrium mass concentration of uranium adsorption of 120 mg/L, the adsorption capacity reaches the 151.6 mg/g. Its adsorption rate is faster in the initial 60 min and reaches equilibrium at 180 min. Using 80 g/L Na₂CO₃+20 g/L NaHCO₃ as the desorption agent, the desorption rate of uranium is 97.5%. For real uranium containing wastewater with high concentration of impurities, the removal rate of uranium can reach 95.6% after single adsorption by AHTCC.

The extraction and separation of ferrum and copper from waste ternary cathode material by Cyanex 302 (the main component is di (2,4,4-trimethylamyl) monothiophosphoric acid) was studied. The effects of H⁺ concentration, extractor concentration and temperature on the extraction and separation performance of Cyanex 302 were investigated. And the technological conditions for the stripping of ferrum and copper in supported organic phase were determined. The process flow of extracting ferrum and copper from waste ternary cathode material leaching solution is designed. The results show that the optimal extraction conditions are 0.1 mol/L Cyanex 302 concentration, 0.1 mol/L H⁺ concentration, room temperature.Under these conditions, the extraction rates of ferrum and copper are over 99.9%, while the extraction rates of Ni(Ⅱ), Co(Ⅱ), Mn(Ⅱ), and Li(Ⅱ) are all below 0.003%. The optimal stripping agent for ferrum is 1 mol/L H₂SO₄, and that for copper is 1.5 mol/L HNO₃.The process can effectively separate copper and ferrum from the leaching solution.

The preparation of activated carbon from coffee grounds by activated roasting coffee grounds with NaOH and the adsorption and removal of Cu(Ⅱ) from wastewater containing copper were studied. The activated carbon of coffee grounds was characterized by SEM and EDS. The effects of initial pH of wastewater, initial mass concentration of Cu(Ⅱ), adsorption time and amounts of adsorbent on the adsorption of Cu(Ⅱ) were investigated. The results show that for the 50 mL simulated copper-containning wastewater with mass concentration of 50 mg/L and pH=6, under the optimal conditions of activated carbon from coffee grounds amounts of 10 mg, temperature of 25 ℃ and stirring speed of 150 r/min and adsorption time of 9 h, the Cu(Ⅱ) adsorption removal rate can reach 94.12%. Langmuir isothermal adsorption model and quasi-second-order kinetic model can describe the adsorption process well. The adsorption performance of Cu(Ⅱ) in wastewater is good.

In order to promote the recovery and utilization of valuable resources in steel slag, the leaching behavior of each element in converter steel slag in mixed acid (citric acid+nitric acid) system was studied. The effects of mixed acid concentration, reaction time, reaction temperature, liquid volume to solid mass ratio, and slag particle size on the leaching rate of each valuable element were examined. The results show that acid concentration, reaction time, liquid volume to solid mass ratio, and slag particle size have significant impact on the leaching rate of calcium, magnesium, iron, manganese and phosphorus. The reaction temperature has little effect on the leaching rate of each element. Under the conditions of steel slag particle size of 65 μm, leaching temperature of 298 K, leaching time of 30 min, liquid volume to solid mass ratio of 300∶1 and stirring speed of 800 r/min, the leaching rate of phosphorus is 88.15% with 0.01 mol/L nitric acid and 20.8 mmol/L citric acid. And effective leaching of phosphorus is obtained.

Platinum and its composite powder are widely used in electronic information, energy, automotive and other high-end manufacturing fields, due to its unique performance. With the high-quality and rapid development of Chinese advanced equipment manufacturing industry, higher requirements are put forward for the performance of platinum and its composite powder, and the demand for dosage is increasing. In this paper, the most widely used liquid phase method for preparing platinum and its composite powder at home and abroad is reviewed. The research progress of sol-gel method, hydrothermal method, microemulsion method and liquid phase chemical reduction method for preparing platinum and its composite powder is summarized, and the advantages and problems of various method in the process of preparing precious metal powder are also summarized. The development direction of efficient preparation of platinum and other precious metals ultrafine powders is prospected.

Gallium, indium, cadmium, selenium, tellurium, germanium, thallium and other rare disperse elements are often present in copper deposits, and accurate analysis of these elements is beneficial to comprehensive utilization of minerals. The determination of Ga, Ge, In, Tl, Se, Te and Cd in copper ore by microwave digestion and inductively coupled plasma mass spectrometry was established. The symmetric sample size, acid system, ethanol concentration, microwave digestion work conditions and mass spectrum interference were optimized. The results show that under optimized conditions, the linear correlation coefficient of the calibration curve is greater than 0.999 5, and the detection limit is 0.002~0.19 μg/g. The relative standard deviations (RSD, n=6) are 2.63%~13.84%, and the standard recoveries are 90.4%~110.6%. The method is accurate and reliable, and the results are consistent with the standard method.

The adsorption and desorption properties of MTA1701 and RCX5143 macroporous weak basic anionic resins for rhenium recovery in arsenic reduction solution were studied. The effects of pretreatment method, time,temperature,acidity and equilibrium concentration on adsorption of rhenium using resin were investigated by static adsorption. Static desorption of ammonia water was used to investigate the effects of ammonia concentration, desorption volume ratio, desorption time and desorption times on the desorption rate of supported resin. The results show that the properties of the two resins are similar, and the adsorption reaction of the resin is in accordance with the quasi-second-order reaction kinetics model after the pretreatment of sulfuric acid soaking. The thermodynamic results show that decreasing temperature is beneficial to the adsorption of rhenium. The static equilibrium adsorption capacity decreased with the increase of acidity and increased with the increase of equilibrium concentration. Under the conditions of ammonia concentration of 10%, V(ammonia)∶V(resin) of 2∶1, desorption time of 20 min for 2 times desorption, the desorption rates of the two resins are all greater than 99.5%.

The effects of solution coordination environment on the extraction of vanadium by P204 were investigated. The effects of chloride, fluoride and sulfate ions on the extraction of vanadium and their coordination with vanadium were examined at different pH. The results show that for the extractant using an organic phase composition of 20%P204+5%TBP+75%sulfonated kerosene, at phase ratio of V_O/V_A=1/2 and extraction time of 8 min, chloride ions can effectively enhance vanadium extraction. At pH=1.0 and [Cl^-]=5 mol/L, the vanadium extraction can reach 87.93%. When the pH is 1.4~2.2, fluoride ions in a certain concentration range can promote the extraction, and the best promotion effect is achieved when [F^-]=0.05 mol/L. The concentration of fluoride ion is greater than 0.2 mol/L, and the extraction is inhibited. When pH=1.8 and 2.2, the concentration of sulfate has little effect on vanadium extraction. But when pH=1.0 and [$\mathrm{SO}_{4}^{2-}$]=1.5 mol/L, the vanadium extraction rate is only 52.22%, and the high concentration of sulfate can significantly inhibit vanadium extraction. The thermodynamic results show that coordination groups VOCl⁺ and VOF⁺ can enhance vanadium extraction process. When the concentration of fluoride ion is higher than 0.2 mol/L, the coordination anion VOF₃ formed by VO²⁺ and multiple F^- prevents the cation exchange reaction of P204.