Qi Cheng Feng

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.

The Progress of Mineral Processing Technology of Lead-Zinc Mine in China

This paper discusses the progress of lead-zinc mineral processing technology and flotation reagents of China, and proposes that optimize technological process and develop new reagents are the main directions.

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.

The Dissolution of Zinc Oxide Ore in Sulfamic Acid Solution

In this study, the dissolution effect of zinc oxide ore was investigated using sulfamic acid solution as leaching agent. The effects of temperature, concentration of sulfamic acid, average particle size and stirring speed on the dissolution of zinc oxide ore were investigated. The dissolution rate increased with increasing solution temperature, concentration, and stirring speed as well as with decreasing average particle size. Sulfamic acid solution can therefore be used as an effective leaching agent for zinc extraction from zinc oxide ore.

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.

Recovery of Molybdenum from Molybdenum Ore with a High Content of Carbon by Separating Carbon from Sulfur

The study was aimed to recover molybdenum minerals from molybdenum ore with a high content of carbon by flotation process. The material belonged to a kind of refractory molybdenum ore from which molybdenum minerals could not be extracted effectively using traditional beneficiation and metallurgy, because of their similar floatability between carbon minerals and molybdenite and complex intergrowth. Based on the research on the properties of the material and lots of experiments, the carbon-molybdenum bulk flotation experiment was firstly carried out to concentrate molybdenum, and then some potassium permanganate and lime were added in carbon-molybdenum bulk flotation products to inhibit sulfide minerals along with appropriate air agitation. Under such a condition, the floatability of sulfide minerals was weakened and carbon was separated from sulfur. Then carbon concentrate and sulfur concentrate were used to extract molybdenum through metallurgy respectively.

Extraction of Copper from a Refractory Copper Oxide Ore by Catalytic Oxidation Acid Leaching

The study aimed to extract copper from copper oxide ores in which copper minerals had a complex association and dissemination with gangue minerals in the form of fine grain by catalytic oxidation acid leaching. Based on the research on the properties of the material and lots of experiments, the leaching process was performed. The optimum parameters of leaching process were determined as sulfuric acid dosage of 150 kg/t, KMnO4 dosage of 1500 g/t, liquid/solid mass ratio of 3 and leaching time of 45 minutes. Under such a condition, the leaching efficiency of 90.15% was achieved, which provided a way to improve leaching efficiency of copper for refractory copper oxide contained some copper sulphide using catalytic oxidation acid leaching.

Influence of Flotation Reagents on Utilization of Complex and Refractory Lead Oxide Ores

The study aimed to explore appropriate flotation reagents to utilize lead minerals from complex and refractory lead oxide ores in Yunnan. Based on the research on the properties of the material, the reagent regime was investigated and a technological flowsheet consisting of one roughing flotation, two scavenging flotation and two concentrate flotation was adopted to perform the closed circuit flotation experiment. The optimum regulator of flotation experiment was determined as sodium silicate, sulfidizing agent as Na2S and collector as isoamyl xanthogenate. Under such a condition of reagent types and their appropriate reagent dosages, a lead recovery of 76.55% with a concentrate grade of 58.67% was obtained, which effectively improved utilization of lead resource.

Effect of Reagent Regime on Flotation Performance of Refractory Oxidized Copper Ores Containing a High Content of Slime

The study aimed to explore appropriate flotation reagents to recover copper minerals from a high content of slime and refractory oxidized copper ores. Based on the research on the properties of the material, the reagent regime was investigated and a technological flowsheet consisting of one roughing flotation, two concentrate flotation, three scavenging flotation and one concentrate-scavenging flotation was adopted to perform the closed circuit floatation experiment. The optimum depressor of flotation experiment was determined as CHO, activator as (NH4)2SO4 and collector as isoamyl xanthogenate. Under such a condition of reagent types and their appropriate reagent dosages, a copper recovery of 75.03% with a concentrate grade of 18.01% was obtained.