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1

Study on flotation behavior and mechanism of separating chalcopyrite and Molybdenite with ethyl mercaptoglycolate as inhibitor

Yang Xiao-Feng, Xu-Zhao, Liu Yao-Yao

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 2

art. no. 162824

EN

The effect of ethyl thioglycolate organic small molecule inhibitors on chalcopyrite molybdenite flotation behaviour is investigated via single mineral micro-flotation tests, zeta potential tests, and X-ray photoelectron spectroscopy (XPS) analysis. Results of the flotation test indicate that ethyl thioglycolate organic small-molecule inhibitors can effectively separate Cu and Mo and selectively inhibit chalcopyrite under weak alkaline conditions. Infrared spectroscopy and XPS analysis show that hydrophilic functional groups C=O and -COOH in the ethyl thioglycolate organic small molecules can chemically adsorb onto the chalcopyrite surface. Moreover, ethyl thioglycolate has no obvious effect on zeta potential of molybdenite. Therefore, ethyl thioglycolate can effectively separate chalcopyrite and molybdenite.

2

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.

3

Insights into the depression effect and adsorption mechanism of HACC on chalcopyrite surface in Cu-Mo flotation separation

Li Mingyang, Zhang Pengpeng, Xiangpeng Gao, Huang Lingyun

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 6

art. no. 172481

EN

In this study, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) was first introduced as a depressant during separating chalcopyrite from molybdenite (Cu-Mo). The selective effects of HACC on the separation of Cu-Mo were conducted by single-mineral flotation experiments. The findings from this study revealed that HACC helped separate Cu and Mo efficiently at pH 6 with 8 mg/dm3 of HACC, resulting in 76.22% and 5.38% of Mo and Cu flotation recovery, respectively. The adsorption mechanism of HACC was investigated via zeta potential, adsorption density, and contact angle measurement along with FT-IR and XPS analyses. The contact angle and adsorption density measurements offer indisputable proof that HACC can adsorb on the surface of chalcopyrite. Furthermore, FT-IR and XPS analyses confirm that N atoms in quaternary ammonium groups of HACC interact with Cu sites on the surface of chalcopyrite. The findings also suggest that HACC adsorbs on the surface without significantly impacting molybdenite. All these results confirm that HACC can be an effective chalcopyrite depressant.

4

Influencing mechanisms of sodium hexametaphosphate on molybdenite flotation using sea water

Wang Lizhangzheng, Li Yubiao, Fan Ruihua, Fan Rong

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 5

1091--1098

EN

Flotation using sea water has been considered as a promising alternative to concentrate molybdenite (MoS2) under alkaline conditions due to scarcity of fresh water and increasingly strict regulations on the quality of discharged water. However, the MoS2 recovery with sea water during flotation has not been satisfactory, owing to the depressing effects from the hydrophilic metallic species onto MoS2 surface. This study combines experimental and theoretical studies of MoS2 flotation to investigate how the physicochemical properties of MoS2 vary with the addition of a dispersant, sodium hexametaphosphate (SHMP), and in sea and fresh water. Our experimental results show that the addition of SHMP during flotation has increased the recovery of MoS2, via reducing the adsorption of the hydrophilic metallic precipitation onto MoS2 surface. The DLVO calculation confirms that the addition of SHMP increases the floatability of MoS2 by dispersing the formed hydrophilic metallic precipitation (Mg(OH)2 colloids) from the MoS2 surface, via reversing attraction force to repulsion force, thereby improving MoS2 flotation recovery.

5

Rhenium abundance in molybdenites : a case study on vein-type Cu-Mo-Au mineralisation in the Qarachilar area, Sungun porphyry Cu and Siah Kamar porphyry Mo deposits, NW Iran

Simmonds Vartan, Mathur Ryan, Selby David

Geological Quarterly

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2019

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Vol. 63, No. 3

478--492

EN

The vein-type Cu-Mo-Au mineralisation in Qarachilar, the Sungun porphyry Cu deposit (PCD) and the Siah Kamar porphyry Mo deposit (PMD) are all located at the northwestern end of the Neo Tethys-related Urumieh-Dokhtar volcano-plutonic belt of Iran. Re contents of moIybdenite samples from the Qarachilar, Sungun and Siah Kamar deposits are about 112.67-462 ppm, 53.24-252.29 ppm, and 10.44-41.05 ppm, respectively. Re contents of the first two deposits fall in the range of PCDs, while those of the latter are lower and correspond to PMDs. The relatively high Re content of the Qarachilar and Sungun molybdenites can be explained considering the low abundance of molybdenite, a mantle-dominated source for ore materials and the incorporation of oxidized and acidic hydrothermal fluids with high fCl. The high abundance of molybdenite in the Siah Kamar PMD has resulted in volume dilution of Re. Furthermore, occurrence of the main ore within the potassic alteration zone and, hence, the alkaline nature of the responsible fluids in this zone have also affected the Re content of molybdenites. Variations of the Re content in different veins/veinlets showed a negative relationship with the formation temperature of these veins, and a positive/negative relationship with the acidity/alkalinity of the hydrothermal fluids, while the grain size of molybdenites showed a positive relationship.

6

Physico-chemical factors in flotation of Cu-Mo-Fe ores with seawater: a critical review

Castro S.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 4

1223--1236

EN

This paper aims to provide a comprehensive review on the physico-chemical factors governing the flotation of Cu-Mo-Fe sulfide ores in seawater, which is different from NaCl or KCl solutions because it contains hydrolysable ions such as Mg2+, Ca2+, HCO3-, CO32-, etc., which can precipitate with lime as hydroxides, Ca, and Mg insoluble salts. Under pH 9.0 Mg2+ ions do not depress molybdenite. However, over the critical pH of precipitation of Mg(OH)2 (pH>10.0), molybdenite is strongly depressed in seawater. This detrimental effect on molybdenite discards the use of lime to depress pyrite in Cu-Mo-Fe ores floated in seawater. In plant practice, the use of sodium metabisulfite (MBS) has replaced lime as a pyrite depressant. It works at pH 6.5-7.0 where the natural floatability of molybdenite is enhanced. Consequently, pH control in rougher and cleaning circuits, and the use of MBS to depress pyrite, have allowed the successful use of non-desalinated seawater in flotation of Cu-Mo-Fe sulfide ores at industrial scale.

7

Flotation of molybdenite in the presence of microemulsified collector

You X., Li L., Lyu X.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 1

333--341

EN

In this paper molybdenite flotation using microemulsified collector was reported. The flotation performance of microemulsified collector and conventional diesel was compared. This study is a prelimi-nary investigation which uses pure molybdenite mineral in a modified Hallimond tube. The pH tests showed that the highest recovery of molybdenite in the presence of diesel and microemulsion was ob-tained at pH=6, reaching the recoveries of 93% and 90%, respectively. In the case of obtaining similar results, it was observed that the microemulsion consumption was lower in comparison to diesel. In the flotation tests with microemulsified collector the recovery slightly decreased because too large collector amount caused formation of more unstable bubbles. The contact angle measurements showed that the microemulsified collector was more effective for increasing the hydrophobicity of molybdenite surface. An adsorption model was proposed and it was suggested that the non-ionic surfactant present in the mi-croemulsified collector formed a continuous bimolecular layer, resulting in the increased surface hydro-phobicity. The accomplishment of this research demonstrated the viability of the use of microemulsified collector in molybdenite flotation, attempting to simplify the molybdenite flotation process, especially replace the conventional emulsified collector with high energy consumption and difficult storage.

8

Wiek molibdenitów w Polsce w świetle badań izotopowych Re-Os

Mikulski S.Z., Stein H.J.

Biuletyn Państwowego Instytutu Geologicznego

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2012

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nr 452

199--216

PL

W artykule przedstawiono wyniki datowań metodą Re–Os wieku molibdenitów związanych z waryscyjskimi intruzjami granitoidowymi w Polsce. W masywie karkonoskim oraz w jego wschodniej osłonie metamorficznej stwierdzono dwa etapy krystalizacji molibdenitów (od 326 ±1 do 310 ±1 mln lat), które odzwierciedlają aktywność pneumatolityczną i hydrotermalną w okresie karbońskim od wizenu/ serpuchowu do moskowu. W masywie Strzegom–Sobótka zarówno molibdenity rozetkowe występujące w formie impregnacji w granitach, jak i molibdenity w przecinających je żyłkach kwarcowych wykazują zbliżony wiek (od 309 ±1 do 296 ±2 mln lat). Krystalizacja molibdenitów w tym masywie była pochodną procesów pomagmowych związanych z powolnym stygnięciem magm odpowiedzialnych za powstanie monzogranitów hornblendowo-biotytowych. Zakres wiekowy krystalizacji molibdenitów ze strefy kontaktu bloku małopolskiego z blokiem górnośląskim mieści się w czasie od 301 ±2 do 296,3 ±1,4 mln lat. Najstarszy wiek izotopowy Re–Os krystalizacji wśród zbadanych dotychczas molibdenitów uzyskano dla próbki molibdenitu pochodzącej z Tatr – 350,5 ±1,2 mln lat. Z kolei najmłodsze wieki krystalizacji molibdenitów stwierdzono w próbkach z kamieniołomu w Siedlimowicach (257 ±1 mln lat) oraz w Miedziance (213 ±1 mln lat). Wieki te wskazują na procesy kataklazy i remobilizacji roztworów hydrotermalnych w młodszych okresach, tj. w późnym permie i triasie. Wyniki badań izotopowych molibdenitów pozwoliły określić relacje czasowe pomiędzy poszczególnymi hydrotermalnymi etapami krystalizacji kruszców i procesami magmowo-tektonicznymi w czasie ok. 140 mln lat, tj. od missisipu (karbon) do noryku (późny trias) w różnych obszarach wystąpień waryscyjskich intruzji granitoidowych w Polsce.

EN

The paper presents the results of molybdenites that closely correlate with the Variscan granite intrusions in Poland. In the Karkonosze Massif and its eastern metamorphic cover, there are two separate stages of Re-Os ages of molybdenite crystallization (326 ±1 to 310 ±1 Ma), which reflect pneumatolitic and hydrothermal activity in the Carboniferous (from the Visean/Serpukhovian to the Moscovian). In the Strzegom–Sobótka Massif, both rosette-like molybdenites disseminated in granitoids and those from the quartz veinlets reveal similar Re-Os ages that range from 309 ±1 to 296 ±2 Ma. Molybdenite crystallization in the Strzegom–Sobótka Massif was related to the post-magmatic processes associated with a slow cooling of magma responsible for the formation of hornblende-biotite monzogranites. The time range of molybdenites crystallization form the contact zone between the Małopolska and Upper Silesian blocks is from 301 ±2 to 296.3 ±1.4 Ma. The oldest Re-Os isotopic age of molybdenite (350.5 ±1.2 Ma) was received for a molybdenite sample from the Polish part of the Tatra Mountains. The molybdenites from the eastern part of the Strzegom–Sobótka Massif (Siedlimowice quarry, 257 ±1 Ma) and from the Miedzianka abandoned Cu (-U) mine (213 ±1 Ma) yielded the youngest Re-Os ages. These ages indicate tectonic reactivation and remobilization of hydrothermal fluids in the Late Permian and Late Triassic. The Re-Os isotopic studies of molybdenites allowed defining the time relation between successive hydrothermal stages of ore precipitation and tectonic-magmatic processes during ca. 140 million years e.g. from the Mississippian (Carboniferous) to the Norian (Late Triassic) in different areas of the occurrence of Variscan granitoid intrusions in Poland.