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Research on optimization method of flotation kinetic model based on molybdenite particle size effect

Wan He, An Yanni, Qu Juanping, Zhang Chonghui, Xue Jiwei, Wang Sen, Bu Xianzhong

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 2

art. no. 163004

EN

Flotation kinetic models can be applied to describe the flotation process and to predict mineral recoveries. However, the size composition of the target minerals in the feed ore fluctuates considerably, resulting in insufficient accuracy with flotation kinetic models. There have been many studies that focus on the investigation of flotation kinetics with different particle sizes, while the optimization methods for flotation kinetic models based on particle size effects have not been reported. In this paper, flotation tests, optical microscope observations, and particle size analysis were used to identify the reasons for the decrease in accuracy of the flotation kinetic model due to changes in the composition of molybdenite particle size. Additionally, an optimization method for the flotation kinetic model was developed based on the particle size effect. The test results show that the accuracy of the flotation kinetic model for fixed particle size minerals is very high, but the predicted results for flotation recoveries of different particle size mineral mixtures have large deviations. The poor accuracy might be due to the autogenous carrier effect caused by the particle size composition fluctuating considerably. The optimization method for the flotation kinetic model is based on the particle size effect. The model can accurately describe the flotation process of molybdenite with different size compositions of molybdenite and predict the flotation recovery of molybdenite.

2

Properties of flash roasted products from low-grade refractory iron tailings and improvement method for their magnetic separation index

Wan He, Lu Xianlu, Luukkanen Saija, Qu Juanping, Zhang Chonghui, Chen Yanxin, Bu Xianzhong

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 6

art. no. 156725

EN

The properties of flash-roasted products from low-grade refractory iron tailings (IGRIT) and the improved method for their magnetic separation index were investigated by the MLA, XRD, iron phase analysis, and magnetic separation test. The results show the siderite and hematite in the IGRIT have been converted to magnetic iron after the flash roasting treatment with a time of 3-5 s; magnetic iron in roasted products has a monomeric dissociation of 37.20%, and a 75−100% exposed area of contiguous bodies as rich intergrowth was 29.83%, and that a 32.97 poor intergrowth; moreover, magnetic iron is mainly associated with muscovite and quartz. It is also found that the regrindingmagnetic separation (1500 Oe) treatment of the middling was beneficial to obtain more qualified iron concentrate products. Therefore, roasted products magnetic separation process in the absence/ presence of the middling regrinding-magnetic separation treatment obtains an iron concentrate with 60.10%/ 60.12% iron grade and 72.04%/81.13% iron recovery. The iron concentrate from the magnetic separation process with middling regrinding-magnetic separation can have a 9% higher recovery than the process without middling regrinding-magnetic separation. The work is significant for helping to improve the utilization of IGRIT.

3

Effect of the oxygen-containing functional group on the adsorption of hydrocarbon oily collectors on coal surfaces

Wan He, Hu Xianglin, Luukkanen Saija, Qu Juanping, Zhang Chonghui, Xue Jiwei, Li Hui, Yang Wei, Yang Shenghong, Bu Xianzhong

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 4

art. no. 149937

EN

The oxygen-containing functional groups (OCFG) on the coal surface affect the adsorption effect of hydrocarbon oily collectors (HOC). An investigation of the interaction between the HOC and OCFG in the absence and presence of water is conducive to understanding the effect of OCFG type on the adsorption of HOC on the coal surface. In this paper, FTIR analysis was used to analyze the OCFG type of coal surface. The adsorption behavior of HOC on different OCFG surfaces was investigated using molecular dynamics simulation. The results indicated the presence of OCFG such as -OH, -COOH, -C=O, and -COCH3 on the coal surface. In conditions without water, the effect of OCFG on HOC adsorption capability follows the order -COOH > -C=O > -OH > -COCH3. In an aqueous solution, the effect of OCFG on HOC adsorption capability follows the order -C=O>-COCH3>-OH>-COOH. Moreover, the hydrophilicity of OCFG is the key factor that affects the adsorption effect of HOC. In other words, the adsorption effect of HOC on the coal surface in an aqueous solution does not depend on the strength of the interaction between the OCFG and HOC in the absence of water, but on the hydrophilicity of the OCFG. The -COOH and -OH on the coal surface are not conducive to the adsorption of HOC onto the coal surface. Masking the -COOH and -OH of the coal surface is beneficial in improving the coal flotation performance with HOC as a collector.