In the present study, the effect of cementing properties of oil shale ash on the compressive strength of the concrete mixtures produced from oil shale ash, cement, sand, and water was investigated. The used shale ash was produced by direct combustion at 830oC in a laboratory muffle furnace of the El-Lajjun oil shale. Based on the chemical composition of shale ash (OSA), it was concluded that this material consists of a high percentage of CaO which forms the properties of cement materials as well as the contents of SiO2, Al2O3, and Fe2O3 form the properties of pozzolanic materials. Oil shale ash (OSA) materials have diverse applications as alternative materials for the construction industry and construction technology to reduce environmental risks and achieve sustainability. The results showed that the pressed specimen with 40 wt. % OSA content, 50 wt. % sand content and 30% MW obtained the highest compressive strength of about 9.1 MPa after 28 days of hardening. The highest value of 28 days compressive strength for a compacted specimen containing 35 wt. % OSA and 35% MW were achieved with 12 MPa at a compaction pressure of between 25 and 30 MPa. High compressive strength values were found to be achieved in the compressed specimens by controlling mixing water. It is also indicated that the compressive strength increases as OSA content in the compressed specimen increases and increases as compaction pressure increases.
Large reserves of feldspar ore deposits are found in the alkali granite rocks at Al-Madinah province, Saudi Arabia. Magnetic separation and flotation tests were used in order to achieve the aims of this study which are: reduce the iron and titanium contents of Medina feldspar ore, which impart color and decrease the feldspar quality, as well as produce a high-quality feldspar concentrate, which meets the commercial grade of the raw material specifications for the ceramics and glass industry. The obtained results from this study showed that the efficient separation of Feand Ti-bearing minerals could be achieved by a combination of the dry high-intensity magnetic separator at 14.000 gauss and the direct cationic flotations under 500 g/ton dosage of Aero 801 + Aero 825 + Aero 830 mixture in an acidic medium at pH 3. The feldspar concentrate was produced with 65.18 wt.% SiO2, 19.02 wt.% Al2O3, 0.06 wt.% Fe2O3, 0.09 wt.% TiO2 9.09 wt.% K2O and 6.01 wt.% Na2O grades, which meet the commercial scale of feldspar.
The objective of this study was to reduce the contents of iron and titanium heavy minerals of feldspar from Medina syenite ore by a combination of magnetic separation and flotation to obtain the commercial scale of feldspar concentrate for glass and ceramics industries. For the first time, a process flowchart was provided in the light of this study to produce a high-quality K-feldspar product from syenite ore, which meets the requirements of feldspar for glass and ceramics productions. The results reflect that the best performance separation of iron and titanium contents was produced by a dry magnetic separator at 16.000 gauss. The produced feldspar concentrate by magnetic separation yielding 0.54% Fe2O3 with 87% Fe2O3 recovery and 0.57% TiO2 with 16% recovery. The flotation tests were performed on the non-magnetic fraction of the syenite ore. In this stage, the most effective for removal of Fe2O3 and TiO2 from syenite ore was obtained at a 300 g/ton dosage of a mixture of Aeromine 3030C and Aeromine 801 + Aeromine 825 as a collector in an acidic medium (pH 3). The final feldspar concentrate with 0.07% Fe2O3 and 0.06%TiO2 grades was obtained with 89% Fe2O3 recovery and 86% TiO2 recovery. The commercial scale of feldspar concentrate from syenite ore can meet the desired specification of grades 1 and 2 for glass, porcelain, and ceramics industries.
The results of X-ray diffraction, thermogravimetric and FTIR spectroscopy analyses of mineral composition indicated that the El-Lajjun oil shale is principally composed of calcite, quartz with minor amounts of kaolinite), gypsum, and apatite. The obtained oil shale ash products at 830 °C and 1030 °C are dominated by lime, quartz, anhydrite, portlandite, gehlenite, and amorphous phases. The TGA weight loss curves clearly indicate that it occurred in the temperature range from 310 to 650 °C. The decomposition of oil shale carbonates was detected above 750°C. The functional groups in the organic material of oil shale are dominated by the aliphatic hydrocarbons, the semi-ash of which had diverse structures of polycyclic aromatic hydrocarbons. The most intensive of combustion occurred in the temperature range of 400–750 °C. In this temperature range, about 75 wt.% was accounted for the total mass loss.
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The energy crisis is one of the major challenges confronting the cement industry today. Although non-renewable energy sources are becoming scarce, the presence of significant quantities of oil shale indicates its continued use as an energy source in the cement industry. However, significant environmental impacts may occur as a result of the large amount of Oil Shale Ash (OSA). As a result, the researchers are investigating alternative methods for recycling and reusing the OSA in a variety of applications. The purpose of this work was to use OSA as a green substitute component in cement production due to its high calcium oxide (CaO) content, which is the major component of cement clinkers. The chemical composition of OSA and Clinker samples were determined using X-ray fluorescence (XRF) and X-ray diffraction (XRD). OSA and clinker samples were combined in various ratios and then ground in a ball mill to obtain the desired grain size. The new blended products were prepared and tested at Lafarge factory's laboratories. The results indicated that by adding 10 % of OSA to the Clinker, the mixed product performed better than the reference sample. Additionally, using this percentage of OSA results in a 45 % reduction in the power consumption of the grinding process compared to the reference sample.
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