Selective Pre-leaching of Tellurium From Telluride-Type Gold Concentrate

Yang, Wei; Lan, Xuechen; Wang, Qian; Dong, Ping; Wang, Gang

doi:10.3389/fchem.2021.593888

Cited by 5 publications

(4 citation statements)

References 33 publications

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“…Tellurium-containing motifs have a wide application in the range from metallurgy to electronics and the chemical field, − such as solar panels, − thermoelectric materials, − semiconductor devices, − alloys, − and chemical raw materials. , An attempt has been reinvested in the development of synthetic procedures for tellurium-containing compounds by Xu and co-workers in 2019 . They can construct various π-extended tellurium-containing arenes 94 , including tritellurasumanene 94l , through efficient intermolecular and intramolecular coupling process between tellurium powder and cyclic diaryliodoniums 93 (Scheme ).…”

Section: Synthetic Applications Of Cyclic Aryliodoniumsmentioning

confidence: 99%

Recent Progress in Cyclic Aryliodonium Chemistry: Syntheses and Applications

et al. 2023

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Hypervalent aryliodoumiums are intensively investigated as arylating agents. They are excellent surrogates to aryl halides, and moreover they exhibit better reactivity, which allows the corresponding arylation reactions to be performed under mild conditions. In the past decades, acyclic aryliodoniums are widely explored as arylation agents. However, the unmet need for acyclic aryliodoniums is the improvement of their notoriously low reaction economy because the coproduced aryl iodides during the arylation are often wasted. Cyclic aryliodoniums have their intrinsic advantage in terms of reaction economy, and they have started to receive considerable attention due to their valuable synthetic applications to initiate cascade reactions, which can enable the construction of complex structures, including polycycles with potential pharmaceutical and functional properties. Here, we are summarizing the recent advances made in the research field of cyclic aryliodoniums, including the nascent design of aryliodonium species and their synthetic applications. First, the general preparation of typical diphenyl iodoniums is described, followed by the construction of heterocyclic iodoniums and monoaryl iodoniums. Then, the initiated arylations coupled with subsequent domino reactions are summarized to construct polycycles. Meanwhile, the advances in cyclic aryliodoniums for building biaryls including axial atropisomers are discussed in a systematic manner. Finally, a very recent advance of cyclic aryliodoniums employed as halogen-bonding organocatalysts is described.

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Section: Synthetic Applications Of Cyclic Aryliodoniumsmentioning

confidence: 99%

Recent Progress in Cyclic Aryliodonium Chemistry: Syntheses and Applications

et al. 2023

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“…Furthermore, the low valence and stability of tellurium and bismuth in bismuth telluride cooling chips make the direct acid leaching or alkali leaching methods ineffective at dissolving the material. , In the case of the Na 2 S leaching process, a high concentration of Na 2 S results in substantial reagent consumption and generates sodium thioantimonate, a compound that requires additional processing to convert into the more commercially desirable antimony oxide, thus escalating operational costs . Moreover, due to the complex composition of the waste cooling chips, none of these methods can comprehensively recover and separate all the major elements, − leading to significant material wastage. Therefore, enhancing the recovery efficiency of tellurium while effectively recovering other elements and improving the purity of the product at the same time is an issue that requires resolution.…”

Section: Introductionmentioning

confidence: 99%

“…When dealing with mixed solid materials containing tellurium and metals like copper, direct alkali leaching is generally an inefficient method for recovering tellurium, , as the recovery percentage is low and coprecipitation hinders complete leaching of impurities . However, sulfide leaching significantly enhances the leaching percentage . When leaching tellurium-containing alkaline residues, with a Na 2 S concentration of 200 g/L, a temperature of 80 °C, an L / S ratio of 10:1 mL/g, and a leaching time of 60 min, 94.92% of tellurium is extracted .…”

Section: Introductionmentioning

confidence: 99%

“… 11 However, sulfide leaching significantly enhances the leaching percentage. 12 When leaching tellurium-containing alkaline residues, with a Na 2 S concentration of 200 g/L, a temperature of 80 °C, an L / S ratio of 10:1 mL/g, and a leaching time of 60 min, 94.92% of tellurium is extracted. 13 The dissolution of tellurium is governed by a combination of diffusion and chemical reactions.…”

Section: Introductionmentioning

confidence: 99%

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Efficient Separation and Purification Method for Recovering Valuable Elements from Bismuth Telluride Refrigeration Chip Waste

Zhu,

Wang,

Zhu

et al. 2023

ACS Omega

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Bismuth telluride and its alloys are widely utilized in thermoelectric refrigeration and power generation devices. Waste bismuth telluride-based cooling chips contain valuable elements; however, recycling processes for these materials remain underdeveloped due to their complexity. In this study, we developed a concise and efficient chemical method that does not require expensive reagents or equipment, enabling the separation and purification of tellurium, bismuth, selenium, and antimony from waste bismuth telluride-based cooling chips. Initially, the waste was leached with HCl and NaClO 3 to dissolve primary elements and recover 99.9% of selenium using hydroxylamine hydrochloride. Subsequently, Na 2 S and NaOH were employed for precipitation and leaching, resulting in a solution containing tellurium. The precipitated residue was treated with HNO 3 to oxidize antimony into insoluble SbOHN and dissolve bismuth completely. 99.8% of the bismuth telluride waste was dissolved via oxidative leaching through hydrolysis. A small amount of sodium sulfide reduced the precipitation percentage of tellurium from 11.9% to 7.5% in an alkaline solution, and the direct recovery percentage of tellurium in the form of TeO 2 exceeded 90%, while the purity of TeO 2 reached 99.9%. By adjusting the pH of the bismuth solution to 0.15, 98.9% of the bismuth was able to precipitate and be recovered as BiOCl, with the purity also reaching 99.9%. In summary, this study presents an efficient hydrometallurgical method for treating bismuth telluride waste and provides theoretical guidance for reagent dosage, demonstrating the significant potential for industrial applications.

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