Thermal behavior of zinc sulfide concentrates with different iron content at oxidative roasting

Boyanov, B.; Peltekov, Alexander; Petkova, V.

doi:10.1016/j.tca.2014.04.005

Cited by 33 publications

(13 citation statements)

References 32 publications

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“…As oxidative roasting using Na 2 CO 3 is commonly used for the processing of refractory ores, the same process can be used for the pretreatment of GaN refractory material and convert it to gallium metal-based oxides. 30 Oxidative roasting is a fairly common process that is used for processing complex sulfide ores and concentrates, [31][32][33][34][35][36] refractory slag, 37 and low-grade ore. 31,38 In the oxidative roasting, Na 2 CO 3 is used for processing the refractory ores or sulfides ores. 30,38 The oxidative roasting process using Na 2 CO 3 can be used for recycling of complex refractory e-waste such as GaN.…”

Section: Discussionmentioning

confidence: 99%

Recycling of GaN, a Refractory eWaste Material: Understanding the Chemical Thermodynamics

Swain

Mishra

Lee

et al. 2015

Int J Applied Ceramic Tech

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South Korea is a major producer of light‐emitting diode (LED) material, contributing 31% of total LED demand worldwide, and also a major consumer of electronic devices. During manufacturing and after end of life (EOL) of the consumer electronics, significant amount of GaN‐bearing waste is being generated. As the Republic of Korea depends upon the import of all mineral commodities, under the national policy of securing a stable supply, much attention has been paid to the notion of “urban mining.” The stringent international environmental directive for recycling of waste electrical and electronic equipment (WEEE), United Nations Environment Programme (UNEP) E‐Waste Management goal, restriction of the use of hazardous substances in EEE (RoHS), and extended producer responsibility (EPR) have made recycling an important responsibility. Recovery of the gallium from GaN‐bearing waste can be a promising feasible option; simultaneously from the waste, the wealth can be generated. As GaN is a refractory material, which is hard to leach in the recovery process, hence, needs a chemical pretreatment. In this study, thermodynamics of GaN oxidation and oxidative roasting using Na2CO3 has been studied. Thermodynamic feasibility for leaching of oxidized GaN either through acidic leaching or through alkali leaching has been explored.

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Section: Discussionmentioning

confidence: 99%

Recycling of GaN, a Refractory eWaste Material: Understanding the Chemical Thermodynamics

Swain

Mishra

Lee

et al. 2015

Int J Applied Ceramic Tech

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“…Later increases sharply from 400 to about 800 • C, it can be concluded that the oxidation reaction of zinc sulfide proceed gradually according to the temperature condition of zinc sulfide oxidation reaction [19,20], and there is a main phase transformation in this temperature range as well, Figure 2 also can prove that there are some reactions from 400 to about 800 • C. Lastly drop sharply to an almost stable value, which means main reaction have finished by compared with the dielectric properties of zinc oxide we have measured. The dielectric loss factor is the function of frequency because of dipolar rotation and ionic conduction, and ionic conduction is the dominant mechanism at lower frequencies while dipolar rotation is the main source of dielectric loss at higher microwave frequencies [21,22], as shown in the following equation: The dielectric loss factor at 915 MHz from Figure 3b is smaller than that at 2450 MHz from Figure 3d when the temperature under 400 °C, but reverse results when the temperature above 400 °C.…”

Section: Dielectric Properties Of Zinc Sulfide Concentratementioning

confidence: 99%

Dielectric Properties of Zinc Sulfide Concentrate during the Roasting at Microwave Frequencies

Guang-jun

Yang

et al. 2017

Minerals

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Abstract:Microwave technology has a potential application in the extraction of zinc from sulphide ores, knowledge of the dielectric properties of these ores plays a major role in the microwave design and simulation for any process. The dielectric properties of zinc sulfide concentrate for two different apparent densities-1.54 and 1.63 g/cm 3 -have been measured by using the resonance cavity perturbation technique at 915 and 2450 MHz during the roasting process for the temperature ranging from room temperature to 850 • C. The variations of dielectric constant, the dielectric loss factor, the dielectric loss tangent and the penetration depth with the temperature, frequency and apparent density have been investigated numerically. The results indicate that the dielectric constant increases as the temperature increases and temperature has a pivotal effect on the dielectric constant, while the dielectric loss factor has a complicated change and all of the temperature, frequency and apparent density have a significant impact to dielectric loss factor. Zinc sulfide concentrate is high loss material from 450 to 800 • C on the basis of theoretical analyses of dielectric loss tangent and penetration depth, its ability of absorbing microwave energy would be enhanced by increasing the apparent density as well. The experimental results also have proved that zinc sulfide concentrate is easy to be heated by microwave energy from 450 to 800 • C. In addition, the experimental date of dielectric constant and loss factor can be fitted perfectly by Boltzmann model and Gauss model, respectively.

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“…The content of iron in zinc sulfide concentrates is essential for the process of zinc production [17]. This content is typically in the range 3-18% [18], but if it exceeds 8% [19], about 10% of zinc passes into the zinc cake due to the obtaining of zinc ferrite, insoluble in dilute solutions of sulfuric acid.…”

Section: Determination Of Iron In Zinc Concentratesmentioning

confidence: 99%

Application of 4-(2-pyridylazo)resorcinol for flotation-spectrophotometric determination of iron

Toncheva¹,

Gavazov²,

Georgieva³

et al. 2017

Bull. Chem. Soc. Eth.

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ABSTRACT. Optimum conditions for flotation-spectrophotometric determination of iron with 4-(2-pyridylazo)resorcinol (PAR) based on a 1:2 Fe II -PAR complex were found to be as follows: flotation solvent (chloroform), shaking time (2 min), pH (4.50.5), concentration of PAR (2.0×10-4 mol L -1), reducing agent (hydroxylamine hydrochloride), solvent for the floated compound (dimethylsulphoxide, DMSO), wavelength for spectrophotometric measurements (718 nm), and volumes of the organic solvents (5 mL of chloroform and 3 mL of DMSO). Calibration graphs were compared for different volumes of the aqueous phase -10 mL and 40 mL; the corresponding linear ranges were 0.30-1.3 g mL -1 and 0.25-1.0 g mL -1. The iron content was successfully determined in soil samples, reference standard materials (PS-1, COOMET No. 0001-1999 BG, SОD No. 310а-98; PS-2, COOMET No. 0002-1999 BG, SOD No. 311а-98; and PS-3, COOMET No. 0003-1999 BG, SOD No. 312а-98) and zinc sulfide concentrates.

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Thermal behavior of zinc sulfide concentrates with different iron content at oxidative roasting

Cited by 33 publications

References 32 publications

Recycling of GaN, a Refractory eWaste Material: Understanding the Chemical Thermodynamics

Recycling of GaN, a Refractory eWaste Material: Understanding the Chemical Thermodynamics

Dielectric Properties of Zinc Sulfide Concentrate during the Roasting at Microwave Frequencies

Application of 4-(2-pyridylazo)resorcinol for flotation-spectrophotometric determination of iron

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