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Separation of magnesite and calcite based on flotation solution chemistry

Yao Jin, Gong Xiufeng, Sun Haoran, He Ruofan, Yin Wanzhong

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 4

art. no. 149398

EN

The dissolution characteristics of minerals, dissolution of flotation agents in solutions, and equilibrium of dissociations and associations serve as the basis for determining the optimal conditions for the effective components of flotation agents and for evaluating the interaction between flotation agents and minerals. This basis provided the theoretical support for the flotation separation of minerals. Based on this, the flotation separation of magnesite and calcite was realized using sodium dihydrogen phosphate, also known as monosodium phosphate (MSP), as a regulator and dodecylamine (DDA) as a collector. When MSP was used in the DDA system, single-mineral and binary mixed-ore flotation tests revealed that the floatability of calcite was significantly greater than that of magnesite and the separation of magnesite and calcite was more effective, respectively. Zeta potential measurements showed that MSP-containing negative groups could selectively reduce the zeta potential of calcite and promote the adsorption of DDA-containing positive groups on the surface of the calcite. However, this effect was negligible on the zeta potential of magnesite. Due to the stronger affinity of MSP to Ca2+ than that to Mg2+, as demonstrated by Fourier transform infrared and X-ray photoelectron spectroscopy analyses, the MSP was adsorbed onto the surface of calcite primarily by hydrogen bonds rather than magnesite, which promoted the stronger adsorption of DDA-containing positive groups on the surface of the calcite. As a result, the differences in the floatability of magnesite and calcite were enlarged by MSP. Thus, MSP can be utilized an effective regulator for the efficient separation of magnesite from calcite via reverse flotation.

2

Effects of copper ions on malachite sulfidization flotation

Yin Wanzhong, Sheng Qiuyue, Ma Yingqiang, Sun Haoran, Yang Bin, Tang Yuan

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 2

300--312

EN

In this study, the effects of copper ions (Cu2+) on the sulfidization (Na2S) flotation of malachite was investigated using micro-flotation experiments, zeta-potential measurements, X-ray photoelectron spectroscopy (XPS) analysis, adsorption experiments, and Materials Studio simulation. The results indicated that the flotation recovery of malachite decreased after the pretreatment of the mineral particles with Cu2+ ions prior to the addition of Na2S. The results for zeta-potential measurements and XPS analysis revealed that less sulfide ion species in the pulp solution transferred onto the mineral surface, the sulfidization of malachite surface weakened. The adsorption amount of collector on the mineral surface decreased, and this finding was confirmed by the results of the zeta-potential and adsorption experiments. Materials Studio simulation revealed that the adsorption energy of HS- ions and C4H9OCSS- ions on malachite surface increased after the adding of Cu2+ ion. The competitive adsorption made Cu2+ ions depress sulfidization flotation of malachite, the dissolution of mineral surface affected the adsorption of reagents on it, and decreased the floatability of malachite.

3

Effect of pulp temperature on separation of magnesite from dolomite in sodium oleate flotation system

Yin Wanzhong, Sun Haoran, Tang Yuan, Hong Jongsu, Yang Bin, Fu Yafeng, Han Huili

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 4

1049--1058

EN

The influence of pulp temperature on the floatability of magnesite and dolomite were studied by flotation test. Inductive Coupled Plasma Emission Spectrometer (ICP) was used to measure the dissolved metal ion content in the pulp by minerals in solution. X-ray photoelectron spectroscopy (XPS) was used to measure the presence and relative content of metal ions on mineral surfaces and the amount of sodium oleate adsorbed on mineral surfaces was measured by UV-Visible Spectrophotometer (UV-Vis). The results show that magnesite and dolomite have a great difference in flotation performance when the pulp temperature is 15 ℃ and the effective separation of magnesite from dolomite can be achieved. The main reason is that after the pulp is stirred at a pulp temperature of 15 ℃ and the pH of the pulp is adjusted with HCl and NaOH, the amount of metal ions remaining on the surface of the magnesite is much larger than that on the surface of the dolomite. Therefore, the active targets (metal ion) adsorbing oleate ions on the surface of the magnesite are more than that on the dolomite. When magnesite and dolomite coexist, oleic acid ion mainly acts on the surface of magnesite at the optimum temperature, which makes magnesite float up and the separation of magnesite from dolomite could be achieved.