Copper and cobalt were extracted from nickel chloride solution with N235. The various parameters considered in this work were N235concentration, reaction time, phase ratio (O/A) and pH value. The optimum conditions are determined that concentration of N235 in organic phase is 40% (volume fraction), the phase ratio (O/A) is 1:2, pH value is 2~4, chloride concentration is 5.76 mol/L and the reaction time is 4 min. Under the optimized operating conditions, cobalt and copper extracted effectively and the extraction rates at the single stage reached 90% and 97%, respectively. After five stage continuous counter-current process, the concentrations of copper, cobalt, iron in the raffinate are less than 0.0008 g/L，0.008 g/L and 0.0025 g/L, respectively, and the recovery of nickel is higher than 92%. The separation effect is steady and satisfied for the electrolysis.

It is a facile and efficient way to produce grapheme quantum dots (GQDs) through photo-Fenton reaction. However, the fluorescence of the as-generated GQDs is weak. Here, bright yellow-green fluorescent graphene quantum dots (GQDs) were prepared by post-oxidation of the GQDs with H2O2. The fluorescence quantum yields of the post-oxidized GQDs (O-GQDs) increased from 0.08% to 3.3% and the maximum emission wavelength shifted from 450 to 510 nm. The O-GQDs exhibit excitation-independent and pH-dependent photoluminescence behaviors. The increase of the photoluminescence intensity is attributed to the more carbonyl and carboxyl groups after the post-oxidation. The post-oxidation treatment offers a simple pathway to enhance the fluorescence of GQDs.

Practical teaching is very important in training innovative and practical abilities of college students. On the basis of nonferrous metallurgy teaching characteristics, practical situation and deficiencies had been analyzed and the teaching reforms in the experiment, practice and design had been proposed. A variety of beneficial attempts have been carried out to strengthen the students engineering consciousness and application ability in the reform practice. Through the reform and practice on the teaching methods, it has reached the aim to cultivate the students and improve the quality of practice teaching.

The acid leaching of spent aerospace material with pollution-free oxidation is discussed. Effect of parameters including initial concentration of hydrochloric acid solution, leaching temperature, reaction time, agitation speed, liquid to solid ratio and concentration of oxidant on valuable element extractions are determined, the optimized conditions are 6 M, 60 °C, 30 min, 250 r/min, 6:1 and 0.0378 mol•L-1•min-1, respectively. The comprehensive results of experiments show that the extracting efficiency of Co and Cu are over 83% and 98% respectively when optimized conditions were adopted.

Electrolytic manganese residues containing a substantial amount of manganese are a potential pollution. Removing water-soluble manganese ions from electrolytic manganese residues by hydrometallurgical process was discussed. In the work, the basic property of the electrolytic manganese residues was analyzed. Based on it, we proposed the suitable method to remove Mn2+ from the slag by pollution-free oxidation in alkaline solution. The results shown that the best conditions to remove Mn2+ were pH 10.5, temperature 55 °C, the flow rate of hydrogen peroxide 0.50 mL·L-1·min-1 and agitation speed 250 r/min. At the optimum condition, the removal ratio of water-soluble Mn2+ exceeded 99.9% and the concentration of Mn2+ in the final solutions was about 3 mg/L.