Jian Guo Yin

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 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%.

Extraction of Copper and Cobalt from Nickel Chloride Solution with N235

Copper and cobalt were extracted from nickel chloride solution with N235. The various parameters considered in this work were N235 concentration, 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.

Removal of Phosphorus from High Phosphorus Iron Ores in Wushan Mountain by Crosscurrent Acid Leaching

In the process of resource utilization of high phosphorus iron ores, phosphorus should be removed first. Compared to other dephosphorization methods, selective leaching with acid has special advantages such as high dephosphorization ratio, low iron loss and so on. However, a large amount of acidic wastewater containing phosphorus was produced after acid leaching. Therefore, the rational use of acidic wastewater and decrease of acid consumption is crucial to remove phosphorus by acid leaching. In this paper, the thermodynamics of the acid leaching was studied according to the existence form of mineral constituents in high phosphorus iron ores from Wushan Mountain. Then, crosscurrent acid leaching was employed to remove phosphorus from high phosphorus iron ores in Wushan Mountain and the changes in dephosphorization ratio, iron loss and acid concentration was observed during the leaching. The results showed that the phosphorus in Wushan iron ores could be removed selectively by acid leaching. After three-stage crosscurrent leaching, the dephosphorization ratio exceeded 74% and the iron loss was under 2.1%. Meanwhile, the acid concentration was decreased to 0.65mol/l in leaching solution, which could be returned to selective leaching after precipitation of phosphorus and supplement of hydrochloric acid.

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.

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.