Decommissioned crystalline silicon photovoltaic solar cells are rich in valuable resources and have recovery value. Increasing the separation efficiency of valuable components and metallurgy, and improving the multi-group decomposition effect of the bonding system are the key to achieve efficient resource recovery. EVA (ethylene-vinyl acetate) bonding behavior was weakened by roasting modification, and multi-component selective crushing characteristics of crystalline silicon photovoltaic solar cells were strengthened. Material distribution, EVA bonding weakening behavior and dissociation effect were analyzed by XRD, TG and SEM, and the target components were recovered step by step by acid leaching method. The results show that after roasting modification and crushing treatment, the bonding degree of EVA decreases, the dissociation degree of EVA increases, and the crushing effect is strengthened. After crushing, the yield of fine-grained components increase by 15%, and the valuable metals in different particle size components are selectively enriched. The selective dissociation behavior of multiple components is strengthened by grinding aid, and the selective crushing effect index φ reaches 0.112. The leaching rates of Cu, Ag, Al and Si are 98.33%, 94.12%, 97.21% and 95.17%, respectively, and the removal rate of Pb²⁺ is 93.53%. This process can provide technical reference for the development of short-range, clean and green recycling process for decommissioned crystalline silicon photovoltaic solar cells.

The sparation and recovery of tin, zinc and cadmium from tin smelting dust by sulfuric acid leaching—removing arsenic with oxidation hydrolysis—replacing cadmium with zinc powder were studied. And the effects of various factors on the sparation and recovery were investigated. The results show that the leaching rates of Zn and Cd are 93.25% and 89.35%, respectively, and the leaching rates of Sn are less than 0. 1% under the conditions of initial sulfuric acid concentration of 15%, liquid volume to solid mass ratio of 3∶1, leaching time of 120 min and leaching temperature of 90 ℃. When the amount of hydrogen peroxide is 2% and the control end point pH is 5, the mass concentration of As in the leaching solution can decrease to 0.1 mg/L after arsenic removal. Under the conditions of reaction temperature of 60 ℃, dosage of zinc powder 1.0 times of the theoretical amount, stirring speed of 250 r/min and reaction time of 30 min, sponge cadmium with cadmium content above 95% is obtained. The process can realize efficient recovery and utilization of valuable metals in tin smelting dust.

With the rapid expansion of the scale of nuclear energy, the proper treatment of radioactive waste generated by the nuclear industry has become one of the most important issues for the further development of nuclear energy. Cyclodextrin, as a kind of cyclic oligosaccharide composed of several glucopyranose units, has a good prospect of application in the field of radioactive ions adsorption and separation, because of its special molecular structure of internal hydrophobicity and external hydrophilicity. However, due to the presence of a large number of hydroxyl groups in the cyclodextrin molecules, they are easily soluble in water. Generally, the solidification of cyclodextrins to insoluble solids is always needed before being used as adsorption materials. Depending on the different methods of "solidification", cyclodextrin based adsorbent materials can be divided into three types:loaded cyclodextrin materials, cyclodextrin polymer materials, and cyclodextrin inclusion complex materials. The synthesis and application research advances of the three types of cyclodextrin adsorbent materials in radioactive ion adsorption and separation are summarized, the related adsorption mechanisms are discussed. Besides, the perspectives of the cyclodextrin based adsorbents in the field of radioactive ion adsorption are presented.

The multi-stage leaching of chromite in HCl-Na₂CrO₄ system has been studied, and the leaching kinetics of main metal elements in chromite has been discussed. The results show that under the optimal conditions of particle size of 45~75 μm, oxidizing agent Na₂CrO₄ dosage of 0.6 times of theoretical dosage, reaction time of 5 h, reaction temperature of 453.15 K, ball to material mass ratio of 1/1, stirring speed of 30 r/min, liquid volume to solid mass ratio of 4 mL/1 g, the three-stage cyclic leaching is carried out, the leaching rates of Cr, Fe, Al and Mg can reach 91.98%, 94.54%, 76.62% and 78.03%, respectively. The acid leaching reaction of chromite is controlled by interfacial chemical reaction. The apparent activation energies of Cr, Fe, Al and Mg are 45.80, 40.43, 42.08 and 43.54 kJ/mol, respectively. In the range of 373.15~473.15 K, and the leaching effect is good.

Aiming at the problems such as low settling speed and poor solid-liquid separation effect of a uranium ore high-calcium slurry, static flocculation method was used to settle high-calcium pulp of a uranium ore, and the effects of flocculant type, dosage, mixed flocculant ratio and adding method on the settling effect were investigated. The results show that the settling rate of high calcium pulp can be significantly increased by the mixed flocculant prepared by WZ944 flocculant and 5330 flocculant. The optimal mass ratio of the two flocculants is 1∶1, and the minimum dosage of the mixed flocculant is 35 g/t. The research results can provide reference for the optimization design of the uranium ore solid-liquid separation process.

Manganese dioxide in pyrolusite was directly reduced to manganese sulfate by high-temperature roasting with ammonium sulfite as reducing agent, so as to achieve efficient extraction of pyrolusite. The effects of mass ratio of ammonium sulfite to pyrolusite, roasting temperature and time, leaching temperature and time on the extraction rate of manganese were investigated, and the optimum process conditions were determined. The results show that the optimal conditions are the mass ratio of ammonium sulfite to pyrolusite of 0.75∶1, roasting temperature of 500 ℃, roasting time of 1.5 h, leaching temperature of 25 ℃, leaching time of 30 min. Under the conditions, the leaching rate of manganese and iron is about 93% and about 9.5%, respectively. The extraction effect of manganese is good.

Combined extraction of nickel and cobalt from nickel chloride solution using di (2-ethylhexyl) phosphonic acid (P204) and triisooctylamine (N235) as extractants was studied. The effects of organic phase P204 volume fraction, phase ratio, solution pH, saponification rate, organic phase N235 volume fraction, Cl^- mass concentration, and reaction temperature on the purification and impurity removal of nickel chloride solution were investigated. The results show that after removing impurities by P204 extraction, N235 is used to extract cobalt and molybdenum from P204 raffinate, the mass concentrations of Ni²⁺ is 218.10 g/L, and the mass concentrations of Cu²⁺, Fe³⁺, Co²⁺, and Zn²⁺ in the residual solution 1.1, 1.2, 1.0 and 0.1 mg/L, respectively, under the conditions of 20% volume fraction of P204 in the organic phase of the P204 extraction and impurity removal process, V_O/V_A=1. 5/1, raw material solution pH=3.5, saponification rate of 50%, reaction temperature of 40~50 ℃, and N235 volume fraction of 16% in the organic phase of the N235 extraction process, V_O/V_A =1.2/1, Cl^- mass concentration≥280 g/L, reaction temperature of 40~50 ℃, P204 Raffinate pH=3.0, and hydrochloric acid acidification concentration of 3 mol/L, which can meet the requirements of producing high quality electrodeposited nickel cathodes.

Arsenic containing non-ferrous metal and precious metal sulfide ore will produce acidic high concentration arsenic solution in the smelting process, which has the characteristics of high arsenic concentration, complex composition, large changes, strong toxicity and difficult to store, such as direct discharge without treatment, will have a great impact on the environment and human health. In this paper, the principles, advantages and disadvantages of chemical precipitation method, evaporation enrichment method and metal powder method are reviewed, as well as the research progress of each method, so as to provide reference for the development of arsenic removal technology.

The preparation of spherical-like battery-grade ferric phosphate by co-precipitation—spray-drying method was investigated using ferrous sulfate heptahydrate (FeSO₄·7H₂O) and ammonium dihydrogen phosphate (NH₄H₂PO₄) as raw materials. The effects of the addition of the surfactant cetyltrimethyl ammonium bromide (CTAB), reaction time, and solution pH on the physical phase and particle size of ferric phosphate were examined. The products were characterized by a laser particle sizer, X-ray powder diffractometer, thermogravimetric analyzer, and field emission scanning electron microscope. The results indicate that under the conditions of a Fe/P molar ratio of 1/1.01, CTAB addition of 0.04 g, reaction time of 1 h, and solution pH of 3.0, the ferric phosphate exhibits the smallest particle size distribution, ranging from 300 to 500 nm, and displays more uniform spherical morphology. Moreover, lithium iron phosphate is prepared by ball milling, mixing and sintering, using the spherical-like ferric phosphate as the precursor iron source. The specific discharge capacity of lithium iron phosphate is150.14 mAh/g at 0.1 C, and the retention rate is 98.9% after 200 cycles at 1 C, the performance is good.

The characteristics, industrial application status and research progress of hydrometallurgy for low grade laterite nickle ore by reduction roasting—normal pressure ammonia leaching and high-pressure acid leaching (HPAL), as well as the development of three generations of HPAL technology are summarized. The nickle-cobalt precipitation and enrichment technology and the application are introduced. The processes advantages and disadvantages of the H₂S precipitation, MgO precipitation, direct NaOH precipitation are analyzed. The effectiveness of new precipitation process with alkali conversion and crystal seed activation has been explored. The development prospect of laterite nickel hydrometallurgical process is also prospected.