scholarly journals Aluminothermic Reduction of Manganese Oxide from Selected MnO-Containing Slags

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 356
Author(s):  
Artur Kudyba ◽  
Shahid Akhtar ◽  
Inge Johansen ◽  
Jafar Safarian
Keyword(s):  
Manganese Oxide ◽  
Reduction Process ◽  
Small Mass ◽  
Aluminothermic Reduction ◽  
Exothermic Reactions ◽  
Al Content ◽  
Slag Chemistry ◽  
Single Process ◽  
High Carbon Ferromanganese

The aluminothermic reduction process of manganese oxide from different slags by aluminum was investigated using pure Al and two types of industrial Al dross. Two types of MnO-containing slags were used: a synthetic highly pure CaO-MnO slag and an industrial high carbon ferromanganese slag. Mixtures of Al and slag with more Al than the stoichiometry were heated and interacted in an induction furnace up to 1873 K, yielding molten metal and slag products. The characterization of the produced metal and slag phases indicated that the complete reduction of MnO occurs via the aluminothermic process. Moreover, as the Al content in the charge was high, it also completely reduced SiO2 in the industrial ferromanganese slag. A small mass transport of Ca and Mg into the metal phase was also observed, which was shown to be affected by the slag chemistry. The obtained results indicated that the valorization of both Al dross and FeMn slag in a single process for the production of Mn, Mn-Al, and Mn-Al-Si alloys is possible. Moreover, the energy balance for the process indicated that the energy consumption of the process to produce Mn-Al alloys via the proposed process is insignificant due to the highly exothermic reactions at high temperatures.

Study of Low-Grade Nickel Laterite Processing Using Palm Shell Charcoal as Reductant

2020 ◽  
Vol 1000 ◽  
pp. 436-446
Author(s):  
Bambang Suharno ◽  
Nolzha Primadha Ilman ◽  
Achmad Shofi ◽  
Deni Ferdian ◽  
Fajar Nurjaman
Keyword(s):  
Sodium Sulfate ◽  
Selective Reduction ◽  
Reduction Process ◽  
Low Grade ◽  
X Ray Diffraction ◽  
X Ray ◽  
Palm Shell ◽  
Higher Temperature ◽  
Nickel Grade

This study was conducted to investigate the effect of palm shell charcoal reductant in the selective reduction of nickel ore with the addition of additive at various temperatures and times. In this present work, 10 wt. % of sodium sulfate as additive and 5, 10, 15 wt. % of palm shell charcoal as reductants were used. The reduction of nickel ore was performed at 950oC, 1050oC, and 1150oC for 60, 90, and 120 minutes. A wet magnetic separation method was then carried out to separate the concentrates and tailings. Characterization of reduced ore was performed by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), while the composition of ferronickel in concentrate was identified by X-Ray Fluorescence (XRF). The result showed that the higher temperature reduction, the higher of nickel grade, and its recovery at the concentrate. Nevertheless, the longer reduction time and the more reductant in nickel ore lowering the nickel grade and its recovery in the concentrate. The optimum condition in this selective reduction process was obtained with the addition of 5 wt. % of reductant and 10 wt. % of sodium sulfate in nickel ore, which was reduced at 1150oC for 60 minutes. It resulted in 4.60% and 73.23% for nickel grade and its recovery, respectively.

Characterization of Silver Binding in Cryptomelane by X-ray Absorption Spectroscopy

1998 ◽  
Vol 524 ◽  
Author(s):  
R. Ravikumar ◽  
D. W. Fuerstenau ◽  
G. A. Waychunas
Keyword(s):  
Manganese Oxide ◽  
Silver Ions ◽  
Oxide Phase ◽  
Synthetic Sample ◽  
Temperature Spectrum ◽  
X Ray ◽  
Room Temperature Sample ◽  
X Ray Absorption ◽  
Temperature Sample

ABSTRACTUsing silver K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy, two different samples of silver-containing manganese oxide were analyzed in the fluorescence mode. For the first sample, silver ions from solution were sorbed onto one synthetic manganese oxide phase, namely cryptomelane (KxMn8O16, where l<x<2). The second sample was a silvermanganese oxide from Colorado. From the EXAFS analysis, silver was found to occupy two different sites in the synthetic sample. The natural samples from Colorado also exhibited a very similar coordination distances as the synthetic samples. In the low temperature spectrum of the synthetic sample at 10 K, the Ag-O peak was found to be missing and the amplitude of the Ag- Ag peak was approximately three times larger than the corresponding room temperature sample.

The Experimental of Low Temperature Color Slip for Decorative on Earthenware Body

2016 ◽  
Vol 690 ◽  
pp. 282-285
Author(s):  
Soravich Mulinta
Keyword(s):  
Low Temperature ◽  
Physical Properties ◽  
Manganese Oxide ◽  
Ferric Oxide ◽  
Potassium Feldspar ◽  
Raw Material ◽  
Blue Color ◽  
X Ray ◽  
Yellow Color

The purpose of the study was to investigate the effects of dolomite body, frit and potassium feldspar on the properties of color slip for decorative method of color slip on earthen ware production. The characterization of raw material was analyzed by X-ray fluorescence (XRF). The experiment started with triaxial blend of dolomite body, frit and potassium feldspar in the defined ratio and then to painting of color slips on earthenware production. After that, firing specimens at 950 °C in oxidation atmosphere. Finally, the specimens were tested microstructure and physical properties. The results showed that the ratio of 50% dolomite body, 40% frit and 10% potassium feldspar were optimum properties for decorative on earthenware body. In color slip consisting of blue color added Cobalt oxide 1% ,Green colors added chromic oxide 10% , Gray color added manganese oxide 10% ,yellow color added stain 2225 10% and hazel color added ferric oxide 2 wt %.

scholarly journals NOVEL COMPOSITE OF SILVER-BACTERIAL CELLULOSE (Ag-BC) FROM SIWALAN SAP (Borassus flabellifer) AND ITS ANTIBACTERIAL ACTIVITY

2020 ◽  
Vol 83 (1) ◽  
pp. 19-25
Author(s):  
Suntini Suntini ◽  
Anastasia Wheni Indrianingsih ◽  
Harjono Harjono
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Cellulose ◽  
Antibacterial Properties ◽  
Reduction Process ◽  
Diffusion Method ◽  
Natural Material ◽  
Gram Positive Bacteria ◽  
Antibacterial Assay ◽  
Natural Composite

Recently, a wound healing from natural composite with excellent properties is in a high demand. In this study, a novel composite of bacterial cellulose made from Siwalan sap (Borassus flabellifer) was achieved. Siwalan is a common plant in Java Island of Indonesia and the application is very limited for beverage only. This study aims to determine the effect of the AgNO3/NaBH4 concentration ratio in the development of Ag-BC composites and its antibacterial properties from Siwalan sap. Ag-BC composites were prepared by impregnating the silver solution into the BC matrix through the reduction process with NaBH4. Characterization of Ag-BC composites conducted using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX). Antibacterial assay was performed using disc diffusion method against Salmonella typhimurium (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. The characterization of Ag-BC composite shows the nanostructure of BC with a length of fiber around 35-60 nm in width. The SEM-EDX micrograph showed that silver particles were impregnated into the BC matrix. Antibacterial activity test results showed that the Ag-BC composite had the ability to inhibit the bacteria S. typhimurium and S. aureus with good inhibition. This result showed the potential application of Ag-BC composite from Siwalan plant as a natural material for medical and pharmaceutical purpose, especially as an antibacterial agent.

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