Wen Juan Zhao

Research on Scandium Recovery and Extraction Process

Some methods and application status for Recovery of scandium and extraction of high purity scandium oxide from materials containing scandium were summarized . some corresponding recovery methods and extraction processes were suggested.

Influence of Pulp pH on Flotation of Fluorite and Calcite

Pulp pH value plays a significant role in the froth flotation. Especially in the flotation of fluorite, the performance of flotation will be affected greatly by pulp pH. MO, a new kind of modified fatty acid was used as collector, and H2SO4 and Na2CO3 were used to regulate pulp pH in the experiment. The mechanism of influence of pulp pH on flotation of fluorite and calcite was investigated by such parameters as fluorite recovery, zeta potentials and the infrared spectroscopy about minerals at different pulp pH values. As is shown in the results, the point of zero charge(PZC) of fluorite is pH=9.5 and the PZC of calcite is pH=8.5. The optimum pulp pH of the flotation of fluorite and calcite is determined as 9.5~10 and 8~9 respectively. pH value should be controlled above 9 to depress calcite. Finally, 9.5~10 was determined as the optimum pH to float the fluorite from the calcium-containing fluorite ores.

Theoretical Calculation of Dissolution Equilibrium for Cerussite in Pulp Solution

The dissolution equilibrium of cerussite within the entire pH range was theoretically calculated, which was based on coordination chemistry, thermodynamics and the mass balance principle of Pb2+ and CO32- in pulp solution. The calculation result showed that the total lead concentration (CPbT) of cerussite decreased significantly with increasing pH below 6 or so; however, at pH of about 10, a reverse trend of CPbT may be observed. Within the pH range from 6 to 10, the CPbT of cerussite remained close and presents a minimum value of around 10-4 mol/L. This paper may provide a theoretical basis for the dissolution process of cerussite and its conditioning stage before benefication by adopting flotation method.

Study on Pre-Concentration and Calcium Removal of Low Grade Zinc Oxide Ore

The zinc oxide sample from the Lanping mine located in the west of Yunnan province，China, is characterized with low grade, high calcium content, high oxidation rate and heavy slime. According to the properties of the ore, a new dressing-metallurgy combined method is proposed to process the ore and the beneficiation part is discussed by this paper. Based on the regulation of reagent scheme, flotation flowsheet of pre-desliming and two rougher is conducted to obtain a zinc concentrate that Zn grade is 18.72% at Zn recovery of 90.88%. The calcium removal rate of zinc concentrate reaches to as high as 78.15% for the flotation operation, which could lay the foundation for the next acid leaching process.

Influence of Collectors on Flotation of Fine Tin Middlings after Gravity Separation

The study was aimed to recover tin minerals from fine tin middlings from Laos after gravity separation. The middlings had a tin grade of 0.5%, belonging to a refractory ore, so flotation was used to recover tin of them. Based on the research of influence of collector on flotation of fine tin middlings, an optimum index was obtained in the closed-circuit flotation. Finally, the concentrate with a tin grade of 3.45% and a tin recovery of 59.85% was obtained, which was concentrated by 6.9 times compared with the crude ore, which greatly improved the economic benefit for the concentrator and highly increases the efficiency of separation.

Effect of Ca2+ and Mg2+ on Floatability of Smithsonite and Hemimorphite

In this paper the effects of Ca2+ and Mg2+ on the floatability of smithsonite and hemimorphite were investigated through microflotation. The flotation tests were performed using purified samples from Lanping mine of China by the microflotation technique. The Ca2+ flotation results showed that the recovery of smithsonite decreased from 89.81% to 83.92% and the recovery of hemimorphite decreased from 84.83% to 76.03% when increasing Ca2+ concentration from 200mg/L to 1000mg/L. Also, while increasing Mg2+ concentration from 200mg/L to 1000mg/L the smithsonite and hemimorphite recoveries declined to reach 80.03% and 71.75%, respectively. It can be concluded that the recoveries of smithsonite and hemimorphite showed a decreasing trend with the increasing of Ca2+ and Mg2+ concentration, and the effect on the recovery of hemimorphite was larger. Moreover, the effects of Mg2+ on the smithsonite and hemimorphite are greater in the same test condition, which could be attributed to the solubility product difference of Ca (OH)2and Mg (OH)2.

Theoretical Calculation of Dissolution Equilibrium for Galena in Pulp Solution

The dissolution equilibrium of galena within the entire pH range was theoretically calculated, which was based on coordination chemistry, thermodynamics and the mass balance principle of Pb2+ and S2- in pulp solution. The calculation result showed that the total lead concentration (CPbT) of galena decreased significantly with increasing pH below 7 or so; however, at pH of about 10, a reverse trend of CPbT may be observed. Within the pH range from 7 to 10, the CPbT of galena remained close and presents a minimum value of around 10-10 mol/L. This paper may provide a theoretical basis for the dissolution process of galena and its conditioning stage before benefication by adopting flotation method.

A Study on LIX84-I Extraction Copper from Ammoniac Leach Solution of Copper Oxidized Ore

Abstract: The extractant LIX84-I that extracted and stripped copper in the ammonia leach solution of copper oxidized ores solution of were mainly studied for the experimentation examined the influence of the LIX84-I concentration, the extraction time, the phase ratio, the pH , the stripping sulfuric acid concentration and the stripping time. Laboratory Investigations indicated that LIX84-I is really an efficient copper extractant with a maximum extraction of as high as 99.91% under the conditions of 5.23g/L Cu in leach solution, LIX84-I concentration 7%, 3 min mixtures, phase ratio 1/1and pH﹥4.5. The stripping can be conducted with the barren electrolyte as a stripping agent in which the sulfuric acid concentration remains about 150g/L, and a stripping rate of 99.92% is obtained.

Impact of Pre-Desliming on Flotation of Low-Grade Zinc Oxide Ore from Lanping

Zinc oxide ore from Lanping contained large amount of fine slime which badly deteriorated flotation performance, and it complexly intergrowed with plenty of alkaline gangues with calcium and magnesium. In order to investigate the impact of pre-desliming on flotation, experiments of direct flotation and pre-desliming flotation were carried out in the work. Finally, a zinc recovery of 88.73% with a Zn grade of 13.93% was obtained in direct flotation test, and a higher zinc recovery of 95.25% with a Zn grade of 13.56% was achieved by pre-desliming flotation. Pre-desliming flotation test was superior to direct flotation test, because of an increase of nearly 7% in zinc recovery under the condition of similar Zn grade. At the same time, dosage of sulfurization agent used in pre-desliming flotation was lower by 46.67% than that in direct flotation, which obviously improved the availability of sulfurization agent. So both product index and economic benefit were enhanced after pre-desliming.

Overview of Bauxite Selective Dissociation in China

This paper introduces the survey of bauxite resources in China, analyses the basal principle of selective dissociation, then details dissociation process flow and selective grinding, finally prospects the future development of bauxite selective dissociation.