Purification of a Nigerian talc ore by acid leaching

Baba, Alafara A.; Ibrahim, Abdullah S.; Bale, Rafiu B.; Adekola, Folahan A.; Alabi, Abdul G. F.

doi:10.1016/j.clay.2015.06.031

Cited by 25 publications

(19 citation statements)

References 35 publications

(45 reference statements)

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“…This characteristic helps to prevent the bonds between the O -T sheets from breaking, making it harder to release octahedral Mg 2+ (Temuujin et al, 2002). Baba et al (2015) and Temuujin et al (2002) reported that 62% and 64% of talc was removed from the structure of the rock in 2 M HCl, 75°C, particle size of 75 μm and 4 M H 2 SO 4 , 80°C, unknown particle size, respectively. However, in our study, talc was seen to remain in the structure of S-MG (Fig.…”

Section: Leaching Experimental Testsmentioning

confidence: 99%

Influence of physicochemical properties of Brazilian serpentinites on the leaching process for indirect CO2 mineral carbonation

et al. 2017

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pH-swing mineral carbonation is kinetically favorable and requires a short reaction time. It must also obtain a high extraction rate for reactive elements in the leaching process. The main purpose of this study is to investigate the behavior of different serpentinite rocks in the leaching processes; the reactivity of Brazilian serpentinite rocks (such as: S-GO and S-MG) is analyzed based on physicochemical properties in order to understand their relationship to leaching efficiency. Surface area-to-volume ratio (S BET /V p) and metals-to-silicon ratio (Σ(Mg, Ca)/Si) were used to measure reactivity. Leaching was carried out to determine Mg and Fe extraction. Reaction conditions for both serpentinite rocks were: 355-250 μm particle size, 4 M HCl concentration, 100°C, and 2 h of reaction time. Characterization results show that both serpentinite rocks (S-GO and S-MG) have high magnesium (Mg) content. S BET /V p was 36 for S-GO and 29 for S-MG, while Σ(Mg, Ca)/Si was 2.64 for S-GO and 1.20 for S-MG. These results suggest that S-GO is approximately 50% more reactive than S-MG, and that S-MG is limited by low accessible surface (S BET /V p) and the high mineralogical complexity (Σ(Mg, Ca)/Si). Leaching results confirmed the reactivity; Mg and Fe extraction from S-GO was 94 ± 1%. However, results for S-MG were 34% for Mg and 60% for Fe. In order to increase the reactivity of S-MG, particle size was reduced to 75-63 μm. Even though S-MG was mechanically activated, Mg and Fe extraction has not increased significantly.

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Section: Leaching Experimental Testsmentioning

confidence: 99%

Influence of physicochemical properties of Brazilian serpentinites on the leaching process for indirect CO2 mineral carbonation

et al. 2017

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“…R 2 ) of 0.7835, and the apparent activation energy ( E a ) for the activated waste phosphors was 10.96 ± 2.79 kJ/mol, and it was the same magnitude as that of the absorption of Eu (III) in solution by graphene oxide nanosheets (7.14 kJ/mol) 37 , which shows the leaching reaction was easy to happen. In general, the apparent activation energy of the diffusion-controlled leaching is ~20 kJ/mol; it is >40 kJ/mol for a chemical reaction-controlled leaching 38 39 40 . The value of the apparent activation energy further supported the result that the rate-controlling step of the leaching process of activated waste phosphors was the diffusion of the reagent through the boundary layer.…”

Section: Resultsmentioning

confidence: 99%

Innovative Application of Mechanical Activation for Rare Earth Elements Recovering: Process Optimization and Mechanism Exploration

Tan

Deng

2016

Sci Rep

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With the rapidly expanding use of fluorescent lamps (FLs) and increasing interest in conservation and sustainable utilization of critical metals such as rare earth elements (REEs), the recovering of REEs from phosphors in waste FLs is becoming a critical environmental and economic issue. To effectively recycle REEs with metallurgical methods, mechanical activation by ball milling was introduced to pretreat the waste phosphors. This current study put the emphasis on the mechanical activation and leaching processes for REEs, and explored the feasibility of the method from both theoretical and practical standpoints. Results showed physicochemical changes of structural destruction and particle size reduction after mechanical activation, leading to the easy dissolution of REEs in the activated samples. Under optimal conditions, dissolution yields of 89.4%, 93.1% and 94.6% for Tb, Eu and Y, respectively, were achieved from activated waste phosphors using hydrochloric acid as the dissolution agent. The shrinking core model proved to be the most applicable for the leaching procedure, with an apparent activation energy of 10.96 ± 2.79 kJ/mol. This novel process indicates that mechanical activation is an efficient method for recovering REEs from waste phosphors, and it has promising potential for REE recovery with low cost and high efficiency.

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“…Menurut teori yang dicetuskan Doland Cressey tersebut, terdapat 3 faktor yang mengakibatkan fraud yaitu tekanan, rasionalisasi, dan kesempatan. Fraud triangle theory merupakan suatu model yang menjadi alasan orang melakukan fraud dengan digambarkan melalui segitiga piramid (Tuanakotta, 2010). Teori fraud triangle muncul atas konsekuensi lemahnya pengawasan serta pengendalian manajerial yang dilakukan perusahaan.…”

Section: Landasan Teoritis Dan Pengembangan Hipotesisunclassified

“…Di samping itu, tekanan seperti misalnya tekanan ekonomi juga menjadi alasan terjadinya fraud. Bahkan, status sosial juga dapat menjadi tekanan tersendiri bagi orang untuk melakukan fraud (Tuanakotta, 2010).…”

Section: Landasan Teoritis Dan Pengembangan Hipotesisunclassified

Determinan Kecenderungan Fraud Berdasarkan Aspek Akuntansi dan Moralitas : Survei pada Industri Rumah Sakit

Rosini

Hakim

2020

Keberlanjutan

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This study aims to analyze the determinants of fraud tendency based on accounting aspects and individual morality. The accounting aspect of this study is reflected in the internal control and information asymmetry. The sample of this study was 134 employees who worked in hospitals in South Tangerang City. By using the linear regression analysis method, this study found a negative effect of internal control on the tendency of fraud. Meanwhile, the effect of information asymmetry and individual morality on the fraud tendency was not proved significantly. Future studies are expected to examine the effect of morality and information asymmetry on the fraud tendency with another method. Hospital management should focus on strengthening its internal control system to minimize the incidence of employee fraud.ABSTRAKPenelitian ini bertujuan untuk menganalisis determinan kecenderungan fraud berdasarkan aspek akuntansi dan moralitas individu. Aspek akuntansi dalam penelitian ini direfleksikan melalui variabel pengendalian internal dan asimetri informasi. Sampel penelitian ini sebanyak 134 karyawan yang bekerja di rumah sakit se-Kota Tangerang Selatan. Dengan menggunakan metode analisis regresi linier, penelitian ini menemukan adanya pengaruh negatif pengendalian internal terhadap kecenderungan fraud. Sementara itu, asimetri informasi dan moralitas individu tidak terbukti mempengaruhi kecenderungan fraud. Berdasarkan hal ini, penelitian berikutnya diharapkan untuk menggunakan metode yang berbeda untuk menelahaan pengaruh moralitas dan asimetri informasi terhadap kecenderungan fraud. Bagi manajemen rumah sakit, sebaiknya memfokuskan diri pada penguatan sistem pengendalian internalnya untuk meminimalisir terjadinya kecenderungan fraud karyawan

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Purification of a Nigerian talc ore by acid leaching

Cited by 25 publications

References 35 publications

Influence of physicochemical properties of Brazilian serpentinites on the leaching process for indirect CO2 mineral carbonation

Influence of physicochemical properties of Brazilian serpentinites on the leaching process for indirect CO2 mineral carbonation

Innovative Application of Mechanical Activation for Rare Earth Elements Recovering: Process Optimization and Mechanism Exploration

Determinan Kecenderungan Fraud Berdasarkan Aspek Akuntansi dan Moralitas : Survei pada Industri Rumah Sakit

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