Wen Qiang Yang

Removal of Phosphate Anions from Aqueous Solutions Using Dolomite as Adsorbent

Dolomite, an industrial solid material was used as an adsorbent to remove phosphate anions from wastewater. The effects of initial pH, initial phosphate concentration, reaction time, reaction temperature and adsorbent dosage on the phosphate removal efficiency were investigated. The results show that the phosphate removal efficiency exceed 99% under the conditions of pH 9.5, temperature 30 °C, reaction time 50 min, particle size <0.074 mm, initial phosphate concentration 50 mg•L-1, adsorbent dosage 10g•L-1 and stirring speed 250 r/min. After phosphate removal reaction, the residual phosphate concentrations completely meet the requirement of national discharge standards of the second category pollution (GB 1A (TP = 0.5 mgL-1)).

Removal of Phosphorus from High-Phosphorus Iron Ores by Sodium Roasting

The phosphorus removal from high-phosphorus iron ores by sodium roasting was studied. The effects of ratio of NaOH to NaCO3, roasting temperature and reaction time on the dephosphorization ratio were investigated. The results showed that the dephosphorization ratio can reach 80.1% under the conditions of ratio of NaOH to NaCO3 5:6, roasting temperature 1100°C, and reaction time 120min. After sodium roasting, the content of phosphorus in iron ore sample complied completely with the requirements of steel production.

Removal of Water-Soluble Manganese Ions from Electrolytic Manganese Residues by Hydrometallurgical Process

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.

Removal Phosphorous from High Phosphorous Converter Steel Making Slag by Hydrometallurgical Process

Removing phosphorus from high phosphorus converter steel slag by hydrometallurgical method was studied in this paper. The influence of different dephosphorizting agents on the effect of phosphorus slag was investigated, and high efficient dephosphorizating agent was found. The effects of reaction time, liquid to solid ratio, stirring speed, reaction temperature and dephosphorizing agent concentration on the impact of dephosphorization were studied. The results showed that on the conditions of the reaction time 40 min, slag particle size <0.147 mm, liquid to solid ratio of 4:1, stirring speed 400 rpm, the reaction temperature 25 °C, and dephosphorizing agent concentration 5 mol/L, the optimum dephosphorization results were achieved. The dephosphorization ratio can reach 70%, and the phosphorus content in steel slag decreased from 1.03% to 0.46%, the total iron content increase from 30.676% to above 44%.

Effect of Flow Pattern on Energy Consumption and Properties of Copper Powder in the Electrolytic Process

Because of distinctive properties, such as dendritic structure, high green strength, and low oxygen content, electrolytic copper powder has been widely used in aviation, aerospace, national defense industry and other domains. But at present, energy consumption of the electrolysis process in copper powder production is high, and the current efficiency is only about 90%. Therefore,the decrease in energy consumption of the electrolysis process has become the major bottlenecks in the development of the enterprises. In this paper, a new electrolysis cell with different electrolyte inlet arranged on the cell was manufactured. Then, the effect of flow pattern of electrolyte on the current efficiency, energy consumption and properties of copper powder was investigated. The experimental results showed that the electrolytic process had the higher current efficiency, lower energy consumption and smaller copper powders when the flow rate is 0.5l/min in the paralleled inlet and 1.5 l/min in the traditional inlet. Under the optimal conditions, the current efficiency, energy consumption and copper powder size were 99.10%, 712.90kw∙h/t and 47.80um respectively. This means an obvious rise in current efficiency and decrease in energy consumption compared to traditional feeding method.

Research on the Reform of Metallurgical Engineering Practice Teaching

The cultivation of the practical ability for Metallurgical Engineering students is very important to help them succeed in a fast paced society and new complex world. In this paper, the current structure of practice teaching system was explained. Meanwhile, based on the detailed analysis of the issues exist in current practice teaching of Metallurgical Engineering, the purpose of the practice teaching was expounded and the reform of the practice teaching was explored.

Removal of Manganese(II) Ions from Wastewater by H2O2 as Oxidant

Removal of manganese (II) ions from wastewater by H2O2 as oxidant was studied. Effects of reaction temperature, hydrogen peroxide concentration, reaction time and calcium oxide concen-tration on the manganese removal were investigated. The results indicated that the removal rate of manganese exceeded 99.9% and the Mn (II) ions concentration of treated wastewater was lower than 0.1 mg·L-1 under the conditions of reaction temperature 55 °C, concentration of H2O2 0.1 mL·L-1, reaction time 70 min, concentration of CaO 0.25 g·L-1.

Kinetics of Phosphorus Removal from High-Phosphorus Iron Ores by HCl Leaching

The leaching kinetics of high-phosphorus iron ores in HCl solution was investigated. The effects of temperature ranging from 27°C to 50°C, particle size from 0.18-1.25 mm and HCl concentration from 0.5 to 3.5 mol·L-1 on the leaching efficiency of phosphorus were determined. The dissolution rates are significantly influenced by the temperature and concentration of acid solutions. The experimental results have been analyzed using the shrinking core model for diffusion control. The calculated apparent activation energy of the process is about 43.48 kJ·mol-1, and a reaction order with respect to HCl is 0.64.

Research and Practice in the Teaching Reform of the Nonferrous Metallurgy

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.

Study on Removing Dissolvable Mn2+ from Manganese Residue by Oxidation at High Temperature

The removal of dissolvable Mn2+ from manganese residue was attempted using strong reduction at high temperature. The effects of the several parameters which including roasting temperature in range of 750-1050 °C and roasting time range of 60-360 min were investigated. An increase in roasting temperature from 750 °C to 1000 °C for 90 min increased manganese removal rate from 50.79% to 90.48%. But effect of roasting time on the rate of manganese removal was not obviously, just from 90.06% for 60 min to 94.76% for 360 min at 1000 °C.