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1

Variability of lead-zinc sulfide ore slurry rheological properties and its influence on flotation conditions

Luo Kehua, Sun Chuanyao, Sun Tichang

Physicochemical Problems of Mineral Processing

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2024

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Vol. 60, iss. 4

art. no. 192663

EN

We investigated how the rheological characteristics of a flotation slurry change in response to variations in mineral species, slurry concentration, and particle size; slurry pH; and collector and rheological control reagent concentrations using slurries containing galena, sphalerite, quartz, and kaolinite. The results indicate that reducing particle size and increasing slurry concentration leads to varying degrees of increase in apparent viscosity and yield stress. At the same particle size, the slurry exhibits the following order of apparent viscosity and yield stress: kaolinite > galena > sphalerite > quartz. In addition, as the slurry’s apparent viscosity and yield stress increase, the rheology decreases, creating progressively unfavorable conditions for the flotation of lead, zinc, and other valuable minerals. Furthermore, changes in pH have no significant effect on the slurry’s rheology when the slurry is comprised of gangue mineral. Moreover, galena and sphalerite depict particle agglomeration in the slurry. Ultimately, the addition of sodium silicate as a rheological control reagent substantially enhances the slurry’s rheological properties. This results in a system where problematic minerals like kaolinite are more effectively dispersed, thereby promoting efficient lead-zinc mineral flotation. Regarding the flotation of lead sulfide and zinc minerals, the addition of kaolinite raises the apparent viscosity of the mixed slurry, hindering the flotation of the valuable minerals. Conversely, quartz lowers the apparent viscosity aiding the flotation separation process. Understanding the relationship between flotation conditions and the pulp’s rheological properties can provide valuable guidance for subsequent flotation tests.

2

Study on recovery of iron and sulfur from high-sulfur magnetite ore

Zhao Yongqiang, Zhou Wen-tao, Sun Tichang, Ahmadzai Asadullah

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 4

art. no. 150889

EN

In this paper, to produce a saleable magnetite concentrate with a sulfur level below 0.20% and recover sulfur concentrate, flotation and magnetic separation tests were undertaken. Results showed that the optimum conditions of flotation were established as follows: grinding fineness of 90% particles passing 0.074mm, pH 6, 400 g/t of CuSO4, and 400 g/t of combined collectors. Under these conditions and magnetic separation, S grade of the magnetite concentrate was reduced from 3.20% to 0.18%, and the Fe grade improved from 57.29% to 71.17%. At the same time a sulfur concentrate with S grade of 38.05% and recovery of 91.32% was also obtained. The XPS results showed that the addition of CuSO4 benefited the formation of hydrophobic Sn2-/S0 and Cu+-xanthate, enhancing pyrrhotite floatability. The flotation separation efficiency could be enhanced using a mixture of collectors, and collector mixture demonstrated three synergetic effects, namely enhanced S recovery, improved adsorption behavior of the collectors and enhanced hydrophobicity of pyrrhotite surface.

3

Effect and mechanism of depressant CK102 on flotation separation of fluorite and dolomite

Li Zhengyao, Wang Xuewen, Xu Chengyan, Sun Tichang, Liu Weiran, Wei Jinzhi

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 3

art. no. 145796

EN

For a low grade dolomite type fluorite ore in the Hebei province, it was observed that the depressant CK102, a mixture of sulfuric acid, sodium silicate and aluminum sulfate, can effectively inhibit the gangue mineral dolomite in the flotation of fluorite. However, the inhibition mechanism of the depressant is still unclear. In this paper, the flotation separation performance and underlying mechanism of CK102 inhibiting dolomite were investigated through mineral flotation tests, adsorption measurements, infrared spectroscopy, and X-ray photoelectron spectroscopy (XPS). The flotation results showed that the inhibition effect of CK102 on dolomite flotation was much more remarkable than that of fluorite flotation under optimum conditions. Adsorption measurements revealed that there was competitive adsorption between the depressant and collector and that the adsorption of the depressant CK102 prevented the collector modified sodium oleate from adsorbing onto the surface of minerals. The FT-IR and XPS results showed that the co-oxygen cross-linked component of the depressant CK102 chemisorbed on the surface of dolomite; the CaSiO3 precipitation was generated from the reaction of CK102 with Ca2+ groups on the surface of the dolomite; Al2MgO8Si2 precipitation was also generated from Mg2+ reacting with the sodium silicate and aluminum sulfate of CK102. The above adsorptions and reactions enhanced the hydrophilicity of the dolomite surface and the dolomite was effectively depressed.

4

The mechanism of CaCO3 in the gas-based direct reduction of a high-phosphorus oolitic iron ore

Wu Shichao, Li Zhengyao, Sun Tichang, Kou Jue, Xu Chengyan

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 4

117--124

EN

Gas-based direct reduction and magnetic separation process was applied in treating a high-phosphorus oolitic iron ore, of which phosphorus mainly occured as Fe3PO7 and apatite. The mechanism of CaCO3 was investigated using XRD, SEM-EDS, and mineral phase analysis. Results showed that when no CaCO3 was added, most of the iron minerals were reduced to metallic iron, while Fe3PO7 was reduced to elemental phosphorus and mixed with the metallic iron particles. When a small amount of CaCO3 was added, CaCO3 preferentially reacted with SiO2, Al2O3 and other components, preventing them from reacting with FeO and resulting in the increase of iron recovery. When the amount of CaCO3 reached 25%, apatite was produced from the reaction of CaO and Fe3PO7, which could be later removed by grinding and magnetic separation.

5

Recovery of nickel and iron from low–grade laterite ore and red mud using co–reduction roasting: Industrial-scale test

Guo Xiaoshuang, Xu Chengyan, Wang Yingshuo, Li Xiaohui, Sun Tichang

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 3

61--72

EN

In this study, the effects of red mud (RM) dosage during the co-reduction roasting of lowgrade laterite ore and RM were investigated. The expanded test was conducted under the following optimized conditions: RM-1 dosage of 15 wt%, anthracite dosage of 13 wt%, a roasting temperature of 1300oC, and roasting time of 3 h. Ferronickel powder was obtained with a nickel grade of 1.95 wt%, iron grade of 83.25 wt%, and nickel and total iron recoveries of 94.71 wt% and 95.98 wt%, respectively. The addition of RM improved the recovery of nickel and total iron in ferronickel powder. The reason was because of the increased intensity of the diffraction peaks of kamacite and iron, and the ferronickel particles grown due to the liquid phase were easier to achieve at a lower melting point. The industrialscale test results showed that ferronickel powder was obtained with average nickel and total iron grades of 1.76 wt% and 86.46 wt%, respectively, which indicated the successful industrial-scale test of co–reduction roasting. Thermodynamic analysis theoretically illustrated the feasibility of the co–reduction of low-grade laterite ore and RM. Increased roasting temperature promoted the reduction of iron oxide and nickel oxide.

6

Effect of direct reduction time of vanadium titanomagnetite concentrate on the preparation and photocatalytic performance of calcium titanate

Li Xiaohui, Kou Jue, Sun Tichang, Wu Shichao, Tian Yuechao

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 1

75--86

EN

Effects of direct reduction time of vanadium titanomagnetite concentrate (VTCE) on the preparation and photocatalytic performance of calcium titanate were investigated in this study. It was found that extending the reduction time could not only promote the formation of calcium titanate, but also facilitate the reduction of iron minerals in the reduction products. The optimum reduction time was 180min under the conditions of CaCO3 dosage of 18wt%, reduction temperature of 1400℃ and lignite dosage of 70wt%. The reduced iron (Fe grade of 90.95wt%, Fe recovery of 92.21wt%) and calcium titanate were obtained via grinding-magnetic separation. Moreover, calcium titanate prepared via the direct reduction method could be used as a photocatalyst, where the degradation degree of methylene blue increased from 25.13% to 60.14% with the addition of calcium titanate. Furthermore, Langmuir Hinshelwood fitting results indicated that the degradation of methylene blue by the calcium titanate prepared under different reduction times conformed to first-order reaction kinetics, where the photocatalytic degradation rate of methylene blue was noted to be the highest for a reduction time of 180 min.

7

Effects and mechanism of Bayer red mud on co-reduction with a saprolitic laterite ore to prepare ferronickel

Wang Xiaoping, Sun Tichang, Wu Shichao, Hu Tianyang, Rong Lingkun

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 4

641--652

EN

Co-reduction of a saprolitic laterite and waste Bayer red mud was investigated to prepare ferronickel powder. The synchronous reduction and comprehensive recovery of nickel and iron in the low-grade laterite ores and iron in the red mud were realized. At the red mud dosage of 50 wt%, ferronickel powder with nickel and iron grades of 5.58 wt% and 89.91 wt% was obtained. The corresponding nickel and total iron recoveries were 93.11 wt% and 90.23 wt%, respectively. The red mud enhanced the nickel recovery of the saprolitic laterite ore evidently, attributing to the formation of low-melting anorthite, omphacite, and diopside during co-reduction. This led that NiO in the saprolitic ore was released. Meanwhile, obvious melting phenomenon of the roasting system was appeared, enhancing the growth of the ferronickel particles.

8

Effects of the fixed carbon and ash in blast furnace dust on its co-reduction with seaside titanomagnetite

Wang Xiaoping, Hu Tianyang, Chen Chuanzhong, Sun Tichang

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 5

1323--1337

EN

Previous research has found that the fixed carbon in blast furnace dust (BFD) could be used as the reductant of co-reduction roasting of the iron oxides in seaside titanomagnetite and BFD to replace coals. This research studied the influence mechanism of the fixed carbon and ash in BFD on coreduction.Results showed that both fixed carbon and ash in BFD promoted the reduction of iron, while ash had adverse effect on separation of titanium and iron. The main mechanism was as follows: The ash in BFD accelerated melting. In addition, the iron oxide in the ash of BFD could be reduced to metallic iron cores more easily in the initial stage, providing the site of inhomogeneous core and promoting the aggregation and growth of metallic iron. Furthermore, the fixed carbon mainly reacted with iron ore by solid-solid reaction, leading to a rapid reduction rate and a high utilization rate of fixed carbon.

9

Effects of Temperature on Fe and Ti in Carbothermic Reduction of Vanadium Titanomagnetite with adding MgO

Li Xiaohui, Kou Jue, Sun Tichang, Wu Shichao, Zhao Yongqiang

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 4

917--927

EN

Effects of temperature on Fe and Ti in carbothermic reduction of vanadium titanomagnetite (VTM) concentrate with adding MgO at 1100~1500℃ were investigated. It was found that most of Fe in the VTM concentrate existed in the form of magnetite and a small amount existed as ilmenite; Ti in the VTM concentrate was mainly present in the form of ilmenite. The temperature had significant effects on Fe and Ti: increasing temperature was beneficial to decrease the Fe content in the magnesium titanate mixture, and the Fe content could decrease to 5.47% at 1500℃. Thermodynamic analysis showed that FeTiO3 and MgO preferentially reacted to form Mg2TiO4, followed by MgTiO3 and MgTi2O5 when the temperature increased from 1100℃ to 1500℃. Results of X-ray diffraction and scanning electron microscopy-energy dispersive spectroscopy analyzes showed that an intermediate product of MgFe2O4 would formed at 1300~1400℃ in the actual experiment. This caused the Fe content in the magnesium titanate mixture to increase from 21.32% to 22.85% when the temperature increased from 1200℃ to 1400℃. In addition, the size of magnesium titanate particles could increase from a few microns to approximately 100 µm when the temperature increased from 1100℃ to 1500℃, which was conducive to realize the separation of metallic iron and magnesium titanate.