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Peng R.,Kunming University of Science and Technology | Li R.,Kunming University of Science and Technology | Yu X.,Kunming University of Science and Technology | Xie G.,Yunnan Metallurgy Group Co.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2016

TiB2 wettable cathode coating was prepared on graphitiferous cathode carbon block by atmospheric plasma spraying (APS). The influence of the plasma spraying parameters on deposition efficiency of the TiB2 coating was examined. The results show that the deposition efficiency of TiB2 coating increases with the spray distance increasing. With the increase of plasma Ar gas flow, powder feed rate and power, the deposition efficiency first increase and then decrease. The deposition efficiency increases with powder size decreasing. The optimized parameters are 80 mm for spray distance, 1900 L/h for plasma Ar gas flow, 120 L/h for carrier Ar gas flow, 35.8 kW for powder, 27.34 g/min for feed rate, ≤37.4 μm for powder size (d50), under which, deposition efficiency is up to 62.7%. The result of the TiB2 coating in 220 kA aluminum electrolysis cell indicate that the content of titanium in molten aluminum is 0.0021wt%. © 2016, Chinese Mechanical Engineering Society of Heat Treatment. All right reserved.


Li Z.,Kunming University of Science and Technology | Li Z.,Kunming Guiyan Pharmaceutical Co. | Chen J.,Yunnan Metallurgy Group Co. | Liu M.,Kunming University of Science and Technology | Yang Y.,Kunming University of Science and Technology
Analytical Methods | Year: 2014

A supramolecular solvent made up of reverse micelles of nonanoic acid, dispersed in a continuous phase of tetrahydrofuran (THF) and water, is proposed for the simple, rapid and efficient microextraction of copper (Cu) and lead (Pb) in water samples prior to flame atomic absorption spectrometry determination. A new Schiff base was synthesized and used as the chelating agent in this study. Some important extraction parameters such as the pH, Schiff base concentration, the composition and volume of the supramolecular solvent and vortex time are evaluated, obtaining the most favorable results. Under the optimized conditions, the calibration curves were linear in the range of 10-800 μg L-1 for Cu and 10-500 μg L-1 for Pb, respectively. The limits of detection (LOD) were 0.29 μg L-1 and 0.45 μg L-1, with the enrichment factors of 27 and 22 for Cu and Pb, respectively. Recoveries of Cu and Pb spiked in water samples were in the range of 91.2-102.1%. The results show that the proposed method is suitable for the determination of Cu and Pb in water samples. This journal is © the Partner Organisations 2014.


Li Z.,Kunming University of Science and Technology | Li Z.,Kunming Guiyan Pharmaceutical Co. | Chen J.,Yunnan Metallurgy Group Co. | Liu M.,Kunming University of Science and Technology | Yang Y.,Kunming University of Science and Technology
Analytical Methods | Year: 2014

A new method based on ultrasound-assisted cloud point extraction (UA-CPE) using the mixture of non-ionic surfactant alkylphenol ethoxylate NP-7 and alkylphenol ethoxylate NP-9 for the preconcentration of trace amounts of lead (Pb) and cadmium (Cd) in water samples prior to determination by FAAS has been developed. In this method, Pb and Cd react with ammonium pyrrolidinedithiocarbamate (APDC), yielding hydrophobic complexes, which then are extracted into the surfactant-rich phase. Compared with the traditional CPE, faster phase separation and higher recovery were obtained using the ultrasound-assisted process and a series of non-ionic nonyl phenol ethoxylate surfactants in the present UA-CPE. Variable parameters affecting the CPE procedure were evaluated and optimized. Under the optimized conditions, the calibration graph was linear in the range of 10-500 μg L-1 for Pb and Cd. The detection limits were 0.5 μg L-1 and 0.28 μg L -1 with relative standard deviations of 2.6% and 3.4% for Pb and Cd, respectively. The enrichment factors were 57 and 63 for Pb and Cd, respectively, for 10 mL of preconcentrated solution. The method was successfully applied to the determination of Pb and Cd in water samples. © the Partner Organisations 2014.


Xing B.,CAS Institute of Automation | Yang Y.,Kunming University of Science and Technology | Yang Y.,Yunnan Metallurgy Group Co. | Qian L.,Yunnan Environmental Monitoring Center
Asian Journal of Chemistry | Year: 2016

A vortex-assisted liquid-phase microextraction was applied for the extraction of trace amounts of platinum(II) prior to flame atomic absorption spectrometry detection in the water sample. Ammonium pyrolysine dithiocarbamate was used as the chelating agent and noctanol as an extractant. The fine droplets of n-octanol were made and dispersed as a cloud in the aqueous sample with the help of vortex mixing. Different parameters such as the pH, the amount of ammonium pyrolysine dithiocarbamate, the composition and volume of the extraction agent and vortex time were studied to get the optimum results. Under optimal conditions, the low limit of detection is 2.0 μg mL-1. Recoveries of platinum spiked into tap water samples were in the range of 85.0∼91.5 %. The relative standard deviations is 2.12 % (n = 6). The correlation coefficient of the calibration curve is 0.9977. The proposed method was successfully applied for the determination of platinum in the real tap water samples.


Li Y.,Kunming Institute of Precious Metals | Li Y.,Sino Platinum Metals Co. | Wang J.-k.,Yunnan Metallurgy Group Co. | Wei C.,Kunming University of Science and Technology | And 3 more authors.
Minerals Engineering | Year: 2010

Low-grade complex Pb-Zn oxide ore is an important source, and the reserve is very great in the world. It is very difficult to obtain Pb and Zn from the source by traditional technology. In this work, a new technology characterized by sulfidation of low grade Pb-Zn oxide ore with elemental sulfur was developed. The effects of temperature, time, particle size and sulfur amount on the sulfidation extent of Pb-Zn oxide ore was studied at a laboratory-scale. The experimental results show that the sulfidation extent of Pb and Zn oxide reaches 98% and 95% under the optimum conditions, respectively. A flotation concentrate was obtained with 38.9% Zn and 10.2% Pb from the materials which was treated by sulfidation, and the recovery of Zn and Pb is 88.2% and 79.5%, respectively. Crown Copyright © 2010.


Zhang B.,Kunming University of Science and Technology | Lei T.,Kunming Metallurgy College | Fang S.,Yunnan Metallurgy Group Co. | Wang X.,Central South University | And 2 more authors.
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2012

The process conditions of vanadium removal from ammonium molybdate solution by chemical precipitation and ion exchange using A and B two kinds of alkaline anion resins were studied. It was found that controlling the pH value between 8 and 9, vanadium existed mainly as VO 3 -, the efficiency of NH 4VO 3's precipitating was significant, and purity of NH 4VO 3 was high as above 98.5%. Resin A could separate vanadium from ammonium molybdate greatly, the best technological conditions were pH value of about 7.28 and reducing the concentration of Cl -. Cl - had strong appetency with resin A, and the increase of Cl - concentration notably reduced adsorption capacity of resin A. Resin A's adsorption capacity of vanadium reached 21.73 g·L -1 under the conditions of 7.27 pH value and without Cl -. This technology could control the concentration of vanadium under 0.02 g·L -1 in ammonium molybdate solution. The highest stripping recovery rate of resin A was 98.68%, this ensured the good recovery result after the separation of ammonium and vanadium. Resin B could effectively recycle vanadium and ammonium from stripping solution of resin A, its adsorption capacity of vanadium reached 26.22 g·L -1, and its adsorption capacity of ammonium reached 71.06 g·L -1. Resin B was optimization of resin A, and it had larger adsorption capacity than resin A.


Huang S.,Kunming University of Science and Technology | Lei T.,Kunming Metallurgy College | Han F.,Kunming University of Science and Technology | Zhou L.,Yunnan Metallurgy Group Co.
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2014

Based on chemical equilibrium calculation method in multi-phase, multi-component system, the distribution behavior of titanium, carbon and associated elements during the smelting process was studied. The calculated results agreed well with the experimental results. The effect of AIR (anthracite to ilmenite ratio) on the distribution of Ti, C, Ca, Mg, Si and Al in slag and metal was analyzed. The results showed that AIR was a significant factor. With the increase of AIR, the mass fraction of TiO2, MgO, CaO, Al2O3, SiO2 in slag increased, while the FeO content decreased. The content of each element in metal increased with AIR increasing, reflected in the increase of mole fraction. Most of the reducing agent was used to restore the TiO2 and FeO, while some C also acted as minority elements. However, the AIR on the amount of C in reducing Fe2O3 had little influence. The impurities enriched in the slag were SiO2, MnO, and V2O5. With the increase of AIR from 120 to 134 kg·t-1, the mass fraction of TiO2 in slag increased from 83.8% to 91.77%, FeO mass fraction decreased from 14.7% to 6.25%. Moreover, Fe in molten iron increased from 6.25 to 7.08 kmol, the carbon content changed from 0.97 to 1.09 kmol. The amount of C participated in reducing TiO2 and FeO increased by about 13%. AIR could be controlled to achieve selective reduction of oxides in the melt. Study on allocation behavior of elements during titanium slag smelting reduction process could help to control the process and improve the slag taste.


Meng L.,Kunming University of Science and Technology | Cheng J.,Yunnan Metallurgy Group Co. | Yang Y.,Kunming University of Science and Technology
Water Science and Technology | Year: 2014

A simple and practical extraction method of supramolecular solvents (SUPRAS) was developed for separation and enrichment of trace amounts of palladium (Pd) and silver (Ag) in water samples prior to flame atomic absorption spectrometry (FAAS) analysis. The SUPRAS selected was made up of an aqueous solution containing tetrahydrofuran and nonanoic acid. Pd and Ag reacted with diethyldithiocarbamate to form hydrophobic chelates, which were extracted into the vesicles of SUPRAS. Different parameters such as the concentration of chelating agent, sample pH, supramolecular solvent and the effect of foreign ions were studied. Under the optimal conditions, the linear ranges of Pd and Ag were from 10 to 1,000 μg/L. The relative recoveries of Pd and Ag in tap and river water samples at the spiking level of 10 ug/mL ranged from 90.8 to 116%. The relative standard deviations were 3.6-4.0% (n = 9), the limits of detection were 2.8 and 1.9 μg/L and the enrichment factors were 36 and 18 for Pd and Ag, respectively. The quantification limits were 3.2 and 2.4 μg/L. The method was successfully applied to the determination of Pd and Ag in water samples. © IWA Publishing 2014.


Zhou T.X.,Kunming University of Science and Technology | Zhou T.X.,Yunnan Metallurgy Group Co. | Peng J.H.,Kunming University of Science and Technology | Kuang Z.E.,Yunnan Metallurgy Group Co. | Wang J.K.,ZINC Inc
Advanced Materials Research | Year: 2014

The effect of ZnO dosage, iron remover and the time duration of neutralization and iron-precipitation on iron removal percentage was investigated to find out the optimal parameters in the technique of ZnO pressurization, neutralization and iron removal, and the residual acid from pressurization lixiviation and neutralization was assayed by using ZnO ore to neutralize and remove iron from lixiviated mineral pulp containing residual acid 20 g/l by simulation of Zn concentrate pressurization and lixiviation in a 2 L autoclave, in order to simplify Zinc pressurization process. The result showed that when Zn lixiviation percentage is higher than 98 %, up to 99.74 % of iron in the lixiviation fluid could be precipitated and the lixiviated fluid contains iron at the level of 20 mg/l, meeting the requirement on pre-purification fluid. © (2014) Trans Tech Publications, Switzerland.


PubMed | Yunnan Metallurgy Group Co. and Kunming University of Science and Technology
Type: Evaluation Studies | Journal: Water science and technology : a journal of the International Association on Water Pollution Research | Year: 2014

A simple and practical extraction method of supramolecular solvents (SUPRAS) was developed for separation and enrichment of trace amounts of palladium (Pd) and silver (Ag) in water samples prior to flame atomic absorption spectrometry (FAAS) analysis. The SUPRAS selected was made up of an aqueous solution containing tetrahydrofuran and nonanoic acid. Pd and Ag reacted with diethyldithiocarbamate to form hydrophobic chelates, which were extracted into the vesicles of SUPRAS. Different parameters such as the concentration of chelating agent, sample pH, supramolecular solvent and the effect of foreign ions were studied. Under the optimal conditions, the linear ranges of Pd and Ag were from 10 to 1,000 g/L. The relative recoveries of Pd and Ag in tap and river water samples at the spiking level of 10 ug/mL ranged from 90.8 to 116%. The relative standard deviations were 3.6-4.0% (n = 9), the limits of detection were 2.8 and 1.9 g/L and the enrichment factors were 36 and 18 for Pd and Ag, respectively. The quantification limits were 3.2 and 2.4 g/L. The method was successfully applied to the determination of Pd and Ag in water samples.

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