scholarly journals Assessing the Grindability Behaviour of Anka (Zamfara State, Nigeria) Manganese Ore towards Effective Manganese Mineral Liberation

Author(s):  
Y. E. Gbadamosi ◽  
O. O. Alabi ◽  
J. O. Borode

The Bond standard grindability test provides a Work Index that is widely used to estimate the energy required for ore grinding. The research investigates the work index of Anka Manganese ore at Anka deposit in Zamfara state, Nigeria. The reference ore (Quartz) was sourced from the studied ore overburden in the mine. The test ore and the reference ore were characterized using Energy Dispersive X-ray fluorescence spectrometer, X - ray Diffractometer and the Scanning Electron Microscope equipped with Energy Dispersive Spectrum. 500 g each of the manganese ore and quartz were sampled and prepared by crushing and grinding to 100% passing 1200 μm sieve. 100 g of prepared ores were charged into array of sieve arranged in √2 series from 1000 μm to 63 μm. Set of sieves were mounted on the Automated Pascal Denver sieve shaker (16153) and was in operation for 20 minutes. The work index of reference ore was used to calculate the work index of the test ore using Gaudin Schuman expression to obtain a work index of 14.16 Kwh/ton for test ore and it lies within the work index of 10-15.14 Kwh/ton for manganese ore stated in the literature and the energy expended to achieve communition at mineral liberation size was calculated to be 3.3984 Kw/ton.

2011 ◽  
Vol 324 ◽  
pp. 505-508 ◽  
Author(s):  
Krit Won-In ◽  
Songtam Suksawang ◽  
Sawet Intarasiri ◽  
Chom Thongleurm ◽  
Teerasak Kamwanna ◽  
...  

The Thai amulets that created in an image of Lord Buddha meditation were made to explain the Dharma of Buddha and believed to bless every life in this world for good karma. Phra Somdej Wat Rakhang amulet is the top of the five most famous Thai amulets. There are many molds with various compositions. In this work, it was the first time that X-ray fluorescence spectrometry methods; scanning electron microscope cooperated with energy dispersive X-ray fluorescence spectrometer (SEM/EDS) and particle induced X-ray emission spectroscopy (PIXE) were carried out to analyze their compositions. Two samples were collected from different molds. Results revealed C, Ca and Si were main composition. The differences in their compositions have been used to identify and characterize for each molds.


Author(s):  
Marc H. Peeters ◽  
Max T. Otten

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.


2013 ◽  
Vol 19 (S2) ◽  
pp. 692-693
Author(s):  
P. Trimby

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.


2021 ◽  
Vol 12 (1) ◽  
pp. 13-18
Author(s):  
Wayan Sujana

Nitridisasi merupakan suatu proses perlakuan panas termokimia yang dimana nitrogen dan amonia didifusikan kepermukaan material (ferro and non-ferro) pada temperatur 500-6000C sehingga membentuk pengerasan kulit akibat terbentuknya lapisan nitrida paduan pada permukaan. Namun pengerasan permukaan ditentukan oleh paduan dari material yang dilakukan proses nitridisasi.Tujuan Nitridisasi adalah untuk memperbaiki ketahanan aus, meningkatkan ketahanan lelah, dan memperbaiki ketahanan tehadap korosi. Proses nitidisasi ini juga dapat mengganti jenis perlakuan panas lain yang menekankan performance yang baik. Pada penelitian ini akan memanfaatkan besi cor nodular yanga akan diproses nitridisasi menggunakan fluidised bed furnace. Pada penelitian ini menggunakan pengujian distribusi kekerasan (metode vickers) untuk mengamati sejauh mana nitrogen berdifusi pada permukaan spesimen, dan pengamatan struktur mikro dengan scanning electron microscope, energy dispersive X-Ray spectroscopy (SEM-EDS).Penelitian ini akan memberikan informasi fenonema proses nitridisasi pada besi cor nodular sehingga mendapatkan suatu analisis yang sesuai dengan metode sehingga menghasilkan kualitas kekerasan permukaan yang baik.


2021 ◽  
Vol 42 (1) ◽  
pp. 40-50
Author(s):  
P. Dhevagi ◽  
◽  
S. Priyatharshini ◽  
A. Ramya ◽  
M. Sudhakaran ◽  
...  

Aim: Removal of lead from wastewater using Azotobacter species and optimisation of various parameters to maximise the adsorption of lead by response surface methodology as a tool. Methodology: The bacterial isolate UBI-7 recovered from sewage water irrigated soil was examined for its biosorption potential towards lead. The lead removal efficiency of Azotobacter salinestris was studied with respect to metal concentration (50-250 mg l-1), contact time (24-120 hrs), and pH (4-8).Using response surface methodology, these factors were optimized and R2 value obtained was 0.9710 for lead ions, which indicates the validity of the model. Observation with Fourier Transform Infrared (FTIR), Scanning Electron Microscope imaging (SEM) and Energy Dispersive X-ray Spectroscopic analysis (EDX) were carried out to confirm lead biosorption by Azotobacter salinestris. Results: The lead tolerant bacterium isolated from sewage water irrigated soil (UBI-7) was recognized as Azotobacter salinestris by 16S rRNA based gene sequence analysis. The highest removal percentage of Pb (61.54) was 50 mg l-1 in 72 hrs equilibration period. Interaction effect between different levels of Pb and different contact time of the solution were found to be significant. Lead biosorption by the organism was confirmed by the changes in stretching intensities of functional groups as well as appearance of strong OH stretching at 3291.69 cm-1. Images obtained from Scanning Electron Microscope and Energy Dispersive X-ray Spectroscopic studies of the bacteria (UBI-7) before and after biosorption clearly indicated lead adsorption. Interpretation: Current study proves that the functional groups of Azotobacter salinestris are involved in lead biosorption from aqueous solution which was confirmed through FTIR.EDX analysis also elucidated the lead absorption by the bacterial cells. Hence, this could be effectively utilized for decontamination of lead from the polluted environment. Key words: Azotobacter salinestris, Biosorption, Lead, Response surface methodology


1981 ◽  
Vol 89 (4) ◽  
pp. 646-650 ◽  
Author(s):  
Paul Bretlau ◽  
Hans Jørgen Hansen ◽  
Jean Causse ◽  
Jean-Bernard Causse

Element analysis of microareas of otospongiotic specimens is described. A total of 36 otospongiotic stapes are ultrasectioned without decalcification and examined using a transmission and a scanning electron microscope (STEM-mode). The latter was equipped with an energy dispersive x-ray analyzer. Twenty of the stapes came from patients who have had sodium fluoride (NaF) treatment (15 to 45 mg/day) for a minimum of 12 months. The otospongiotic stapes are classified as spongiotic and sclerotic according to their pathologic characteristics and state of mineralization. Using the Ca/P ratio as criterion—measured by the characteristic x-ray fluorescence—it was shown in a blind study that the NaF-treated otospongiotic stapes had a statistically higher Ca/P ratio, indicating that the fluoride may stabilize otospongiotic lesions, particularly the spongiotic type with unstable mineralization.


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