Production and Refining of Magnesium Metal from Turkey Originating Dolomite

2012 ◽  
Vol 31 (3) ◽  
Author(s):  
Yeliz Demiray ◽  
Onuralp Yücel
Keyword(s):  
Corrosion Rate ◽  
Magnesium Oxide ◽  
Magnesium Alloys ◽  
Iron Content ◽  
Reduction Behavior ◽  
Magnesium Metal ◽  
Thermodynamic Studies ◽  
Corrosion Tests ◽  
Silicate Formation ◽  
Sludge Phase

AbstractIn this study crown magnesium produced from Turkish calcined dolomite by the Pigeon Process was refined and corrosion tests were applied.By using factsage thermodynamic program metalothermic reduction behavior of magnesium oxide and silicate formation structure during this reaction were investigated. After thermodynamic studies were completed, calcination of dolomite and it's metalothermic reduction at temperatures of 1473 K, 1523 K and within a vacuum (varied from 20 to 200 Pa) and refining of crown magnesium was studied. Different flux compositions consisting of MgClConsiderable amount of iron was transferred into the sludge phase and its amount decreased from 0.08% to 0.027%. This refined magnesium was suitable for the production of various magnesium alloys. As a result of decreasing iron content, minimum corrosion rate of refined magnesium was obtained 2.35 g

Effect of Sn, Zn and Bi Addition on Corrosion Characteristics of Magnesium Alloys Sintered by Spark Plasma Sintering

2018 ◽  
Vol 941 ◽  
pp. 1760-1765
Author(s):  
Satoshi Sunada ◽  
Yoshitaka Matsui ◽  
Syogo Takeuchi ◽  
Taku Iwaoka ◽  
Koichi Sato ◽  
...  
Keyword(s):  
Melting Point ◽  
Corrosion Rate ◽  
Spark Plasma Sintering ◽  
Magnesium Alloys ◽  
Electrochemical Method ◽  
Corrosion Potential ◽  
Elemental Mapping ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Metallic Compounds

Sintered magnesium alloys, which were fabricated by Spark Plasma Sintering (SPS) method, were examined to study corrosion characteristics by electrochemical method, XRD and EPMA. The binary mixtures alloys of a low-melting-point metal powder (Sn, Bi, Sb) of1.0 vol.% and the pure magnesium powder were prepared. In the Mg-1.0vol.%Bi and Mg-1.0vol.%Sn, Mg3Bi2 and Mg2Sn precipitates was recognized by XRD, respectively. In addition, formation of oxide along powder particle boundaries was observed by EPMA elemental mapping in all specimens. In the case of Mg-1.0vol.%Zn, precipitation of metallic compounds was not recognized by these experiments. According to the results of polarization curve measurements, the Mg-1.0vol.%Bi shows highest corrosion potential. However, corrosion rate which was estimated by Tafel method is relatively larger than other alloys due to Mg3Bi2 precipitation. This result suggests that Mg3Bi2 acts as cathode site. The Mg-1.0vol.%Sn shows superior corrosion rale in these alloys.

High-Temperature Corrosion of Ni3Al+ 2.9%Cr Alloy in Ar-0.2%SO2 Gas

2018 ◽  
Vol 775 ◽  
pp. 441-447
Author(s):  
Dong Bok Lee ◽  
Min Jung Kim ◽  
Gyu Chul Cho ◽  
Soon Young Park ◽  
Poonam Yadav
Keyword(s):  
High Temperature ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Kirkendall Effect ◽  
High Temperature Corrosion ◽  
Scale Spallation ◽  
Corrosion Tests ◽  
Cooling Period ◽  
Corrosion Kinetics ◽  
Period 2

The high-temperature corrosion behavior of Ni3Al+2.9 wt% Cr alloy was studied in SO2-containing environment. Corrosion tests were carried out at 900, 1000, and 1100 °C for 100 h in atmospheric Ar-0.2% SO2 gas. The alloy corroded relatively slowly due mainly to formation of Al2O3 in the scale. Its corrosion kinetics deviated from the parabolic corrosion rate law to a certain extent owing to ensuing scale spallation. This was attributed to (1) stress generated during scaling and the subsequent cooling period, (2) voids that formed due to the Kirkendall effect, and (3) incorporation of sulfur in the scale. The scale that formed after corrosion at 900 °C consisted of the outer NiO scale, middle NiAl2O4 scale, and inner Al2O3 scale. The increased corrosion rate at 1000 and 1100 °C led to formation of the outer NiO scale, and inner Al2O3 scale.

Corrosion Protection and Microstructure of Magnesium Alloys Anodized by Phosphate Solution

2010 ◽  
Vol 638-642 ◽  
pp. 1464-1469
Author(s):  
Koji Murakami ◽  
Makoto Hino ◽  
Atsushi Saijo ◽  
Teruto Kanadani
Keyword(s):  
Sodium Chloride ◽  
Magnesium Oxide ◽  
Magnesium Alloys ◽  
Corrosion Protection ◽  
Corrosion Current ◽  
Electrochemical Analysis ◽  
The State ◽  
Phosphate Solution ◽  
Protective Films ◽  
Sacrificial Protection

Corrosion protection by anodization and conversion treatment in phosphate solution was studied by microstructural and electrochemical analysis. Both the anodized and the conversion-treated layers showed sacrificial protection in a solution of sodium chloride. The corrosion current or the dissolving rate of the anodized layer was smaller than that of the conversion-treated surface. The modified layers had another mode of protection to form protective films on magnesium substrate where the original modified layers were mechanically lost. Since the state of magnesium in the anodized layer is close to magnesium oxide, phosphorus in the layer is considered to have an important role in these properties concerning the above corrosion protection.

Corrosion Tests of Zircaloy Hull Waste to Confirm Applicability of Corrosion Model and to Evaluate Influence Factors on Corrosion Rate under Geological Disposal Conditions

2014 ◽  
Vol 1665 ◽  
pp. 195-202 ◽  
Author(s):  
Osamu Kato ◽  
Hiromi Tanabe ◽  
Tomofumi Sakuragi ◽  
Tsutomu Nishimura ◽  
Tsuyoshi Tateishi
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Pure Water ◽  
Influence Factors ◽  
Spent Fuel ◽  
Geological Disposal ◽  
Corrosion Tests ◽  
Temperature Range ◽  
Corrosion Rates ◽  
Temperature Ranges

ABSTRACTCorrosion behavior is a key issue in the assessment of disposal performance for activated waste such as spent fuel assemblies (i.e., hulls and end-pieces) because corrosion is expected to initiate radionuclide (e.g., C-14) leaching from such waste. Because the anticipated corrosion rate is extremely low, understanding and modeling Zircaloy (Zry) corrosion behavior under geological disposal conditions is important in predicting very long-term corrosion. Corrosion models applicable in the higher temperature ranges of nuclear reactors have been proposed based on considerable testing in the 523−633 K temperature range.In this study, corrosion tests were carried out to confirm the applicability of such existing models to the low temperature range of geological disposal, and to examine the influence of material, environmental, and other factors on corrosion rates under geological disposal conditions. A characterization analysis of the generated oxide film was also performed.To confirm applicability, the corrosion rate of Zry-4 in pure water with a temperature change from 303 K to 433 K was obtained using a hydrogen measuring technique, giving a corrosion rate for 180 days of 8 × 10-3 μm/y at 303 K.To investigate the influence of various factors, corrosion tests were carried out. The corrosion rates for Zry-2 and Zry-4 were almost same, and increased with a temperature increase from 303 K to 353 K. The influence of pH (12.5) compared with pure water was about 1.4 at 180 days at 303 K.

Microcalorimetric and thermodynamic studies of CO2 and methanol adsorption on magnesium oxide

2011 ◽  
Vol 257 (15) ◽  
pp. 6952-6962 ◽  
Author(s):  
C. Pighini ◽  
T. Belin ◽  
J. Mijoin ◽  
P. Magnoux ◽  
G. Costentin ◽  
...  
Keyword(s):  
Magnesium Oxide ◽  
Thermodynamic Studies ◽  
Methanol Adsorption

Preparation and Characterization of Polylactic Acid Coating on the Surface of Magnesium Alloy

2015 ◽  
Vol 814 ◽  
pp. 132-136 ◽  
Author(s):  
Xian Yang Hua ◽  
Mei Feng He ◽  
Xiao Qin Zhou
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Magnesium Alloy ◽  
Impedance Spectroscopy ◽  
Corrosion Rate ◽  
Polylactic Acid ◽  
Magnesium Alloys ◽  
Electrochemical Impedance ◽  
Hank’S Solution ◽  
Acid Coating

Magnesium is one of the elements necessary for the body, is the man behind the body’s content of potassium ions within the cell are involved in a series of metabolic processes in vivo, including the formation of bone cells , acceleration of bone healing ability. Resulting from the good mechanical properties and biocompatibility, magnesium alloy is used in medical intervention material, but the high corrosion rate of magnesium alloys is the main drawback to their widespread use, especially in biomedical applications. There is a need for developing new coatings that provide simultaneously corrosion resistance and enhanced biocompatibility. In this work the medical magnesium alloy surface are dipped and coated with polylactic acid, so that obtain a dense uniform polylactic acid coating. And the corrosion resistance of the coating is studied in order to obtain controlled degradable and corrosion resisted magnesium alloy biological material. This paper mainly studies the influence of different concentrations of polylactic acid coating on AZ91D magnesium alloy corrosion resistance. The coated samples were immersed in Hank’s solution and the coating performance was studied by electrochemical impedance spectroscopy and scanning electron microscopy. This research is about the influence of the coating on the corrosion resistance of magnesium alloy through the open circuit potential, polarization curves, electrochemical impedance spectroscopy and Mott-Schottky. The results confirmed that the polylactic acid slow down the corrosion rate of AZ91D magnesium alloys in Hank’s solution. And along with the increase of poly lactic acid concentration, the corrosion resistance of magnesium alloys is improved. There is a wide variation of the corrosion morphology magnesium alloy AZ91D specimens after the surface modification using polylactic acid coating, compared with the unmodified.

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