The Characterization of Libyan Raw Dolomite Samples Using Chemical Techniques
Alzadma Himed,
Mousa May,
Balhassn Ali
Issue:
Volume 4, Issue 2, June 2020
Pages:
18-25
Received:
15 February 2020
Accepted:
9 March 2020
Published:
12 May 2020
Abstract: Dolomite known as dolostone is a double carbonate of calcium and magnesium, CaCO3. MgCO3. After calcite, it is the second most important and abundant of the carbonate minerals. This work aims at processing, investigation and characterization of four different Libyan raw dolomite samples via simple chemical method. Based on a previous geological survey carried out by the industrial research centre (Tripoli), four dolomite samples selected from different locations of Libya namely; El-azizia, Souk El-khamees (sample P1), Nalout, Abu Rashada route, Gherian (sample P2), Sedi El-said, Abu Reshada route, El-gabl El-gharby (sample P3) and Abu Ghilan, north Kaf- Takoot (sample P4), were processed (crushed, ground and sieved), then investigated through their chemical composition using x-ray fluorescence (XRF) technique. Their mineralogical compositions were investigated using x-ray diffraction technique (XRD) and scanning electron microscope (SEM). All the measurement techniques in this work indicated that qualitatively the four investigated samples have a dolomitic nature. It was conformed that the percent of CaO in sample P1 (31.19%) is relatively higher than the standard dolomite (30.8%) which confirms the prediction of the presence of some content of calcite CaCO3 accompanied with dolomite sample P1. In spite of the limited variance in the chemical constitutions determined by x-ray fluorescence compared with classical wet method, the results confirm that the four investigated samples are mainly dolomite and that samples P1 and P2 are relatively purer than samples P3 and P4 which contain larger contents of Fe2O3, Al2O3 and SiO2.
Abstract: Dolomite known as dolostone is a double carbonate of calcium and magnesium, CaCO3. MgCO3. After calcite, it is the second most important and abundant of the carbonate minerals. This work aims at processing, investigation and characterization of four different Libyan raw dolomite samples via simple chemical method. Based on a previous geological sur...
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Metallurgical Analyses of Welding Using a Developed Mini-Robot
Oladebeye Dayo Hephzibah,
Adejuyigbe Samuel Babatope,
Kareem Biliyaminu
Issue:
Volume 4, Issue 2, June 2020
Pages:
26-36
Received:
10 May 2020
Accepted:
25 May 2020
Published:
15 June 2020
Abstract: This research work addressed the mechanical and microstructural properties of welded joints. The results show the minimum average hardness values as 133.83, 102.13, 103.42, 95.15, 96.78 and 117.50 for various mini-robot welded mild steel plates of thickness 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm and 1.0 mm, while the maximum average hardness values were as 145.67, 119.08, 113.28, 106.58, 113.42 and 137.75 respectively. Results of the research have shown that the robot welding samples produced are high in hardness. This is responsible for low tensile stress values that may also mean low mini-robot welded sample extension. The robot welding samples developed gave low tensile strain values and this was expected because the robot welding samples developed had high hardness, low extension and low tensile stress. The microstructural study shows that the welded mini-robot samples had more fine structure than coarse (which is more pearlite than ferrite). The built welding robot has also provided a wide range of welding speeds from experimentation, significantly less welding time, wide weld length. The built welding robot has a range of welding time (4.7-32.94s), welding speed starting at 4.41mm / s over the same range of 0.5-1.0 mm thicknesses for the mild steel plate and weld length. The thicker the mild steel plate, the lower the welding time and the higher the welding speed. This is valid when the built welding robot was used. The built welding robot worked very well and the results of Microstructural Analyses presented quality welds.
Abstract: This research work addressed the mechanical and microstructural properties of welded joints. The results show the minimum average hardness values as 133.83, 102.13, 103.42, 95.15, 96.78 and 117.50 for various mini-robot welded mild steel plates of thickness 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm and 1.0 mm, while the maximum average hardness values...
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Investigation of Misalignment Affects During Creep Testing on the Miniature Pin-Loaded and the Sup-Size Uniaxial Creep Tests Specimens
Issue:
Volume 4, Issue 2, June 2020
Pages:
37-42
Received:
16 May 2020
Accepted:
29 May 2020
Published:
16 June 2020
Abstract: Creep is one of the main engineering problems facing engineers dealing with high temperature components. These components have to be closely monitored, especially after serving 50% of their residual life. For many reason creep engineers has to use small material samples for creep assessments of these components. Many small creep test specimen types can be manufactured using these small material samples; this include the sup-size uniaxial creep test specimen and the pin loaded small creep test specimen. Considering the limitations and the difficulties associated with each testing method is another factor often taken in to account before choosing which specimen type can be used. Traditionally many of creep engineers tend to go for the sup-size uniaxial creep test specimen, because of it is similarity to the standard creep test specimen. However, this specimen type has some limitations; this is include the high possibility of misalignment during the loading application, and this is due to the small size of the specimen. The misalignment effect on the test results normally ignored which can lead to inaccurate results. This paper will be focusing on the misalignment effect on the sup-size uniaxial creep test specimen, and the one-bar and two-bar creep test specimens. Using different values of misalignment the creep results obtained from one-bar and two-bar specimens and the sup-size uniaxial creep test specimen will be compared. The P91 steel at 650°C, which is one of the high temperature materials, will be used for validation.
Abstract: Creep is one of the main engineering problems facing engineers dealing with high temperature components. These components have to be closely monitored, especially after serving 50% of their residual life. For many reason creep engineers has to use small material samples for creep assessments of these components. Many small creep test specimen types...
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