In order to selectively remove nickel ions from the desulphurization tailing of pyrolusite and improve the purity of manganese sulfate, the spongy nickel-imprinted chitosan adsorbent Ni²⁺-IIP was prepared by ion imprinting method and chemical foaming method on chitosan matrix, and its competition and selective adsorption behavior in simulated binary solution were discussed. The effects of temperature, adsorption time and desulphurization tailing pH on the adsorption amount and removal rate of nickel ions and the loss rate of manganese ions in the desulphurization tailing of pyrolusite were also investigated. The results show that in the simulated binary solution, Ni²⁺-IIP still maintains high selectivity for nickel ions, although there is competitive adsorption between manganese and nickel ions. In the actual desulphurization tailing of pyrolusite, under the conditions of pH=5.0, adsorption temperature of 40 ℃ and adsorption time of 1 440 min, the adsorption capacity and rate of removal of Ni²⁺is 15.3 mg/g and 90%, respectively,and the loss rate of manganese ions is about 11%. After 5 adsorption—desorption cycles, the adsorption capacity of Ni²⁺-IIP for nickel ions in the desulphurization tailing reduces 13.1%,and the regeneration performance is good. Ni²⁺-IIP can selectively remove nickel ions from the desulphurization tailing, and purify the manganese sulfate solution.

In order to maximize the extraction efficiency of zinc and germanium from high-silicon and low-germanium zinc oxide dust(ZOD), the ultrasonic enhanced leaching process assisted by sodium dodecyl sulfate (C₁₂H₂₅SO₃Na) was constructed and optimized by response surface method(RSM),and the accurate prediction model of zinc and germanium leaching rate was established. The results show that on the basis of single factor test, the optimal leaching conditions determined by RSM are leaching temperature of 70 ℃, liquid volume to solid mass ratio of 8 mL/1 g and initial acid mass concentration of 160 g/L. The leaching rates of zinc and germanium can reach 96.94% and 85.41%, respectively. C₁₂H₂₅SO₃Na plays a key role as a silica gel inhibitor in the leaching process, effectively preventing the polymerization of silicon ions into silica gel, and this effect is more significant under the combined ultrasonic treatment, reflecting the synergistic benefit between temperature, ultrasound and C₁₂H₂₅SO₃Na.The research results provide an efficient recovery strategy for the resource utilization of high-silicon and low-germanium zinc oxide dust, and provide an important technical reference for the recovery of other high silicon waste.

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 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.

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.

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 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.

In view of the complex structure, difficult flotation and difficult leaching of low-grade mixed tungsten and molybdenum ore of a domestic company, the synergistic leaching of molybdenum and tungsten from molybdenum tungsten ore by hydrochloric acid pretreatment—pyrolusite+sulfuric acid was studied. The effects of various factors on the leaching rate of tungsten and molybdenum were investigated. The results show that under the conditions of hydrochloric acid concentration of 1.5 mol/L, liquid volume to solid mass ratio of 6.5/1 and atmospheric pressure, the tungsten and molybdenum ores are pretreated with hydrochloric acid. Under the optimal conditions of filter slag of 20 g, particle size of 200 mesh, pyrolusite dosage of 4 g, sulfuric acid of 8 mol/L, liquid volume to solid mass ratio of 5/1, temperature of 90 ℃ and leaching time of 3 h, the leaching rates of molybdenum and tungsten are 83% and 73%, respectively.

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.

Leaching of uranium, thorium and rare earth from the monazite selective solution residue were studied by conventional leaching—two-stage countercurrent leaching was studied. The effects of various factors on the leaching was investigated. The results show that the leaching rates of uranium, thorium and rare earth are 98.66%, 95.37% and 64.23%, respectively under suitable conditions using conventional leaching method. Using the two-stage countercurrent leaching method, the leaching rates of uranium, thorium and rare earth can be increased by 0.5%~1.0%, the residual acid of the leaching solution can be reduced by more than 50%, and the solid-liquid separation performance of the slurry can be improved to a certain extent.