scholarly journals Properties of Raw Saudi Arabian Grey Kaolin Studied by Pyrrole Adsorption and Catalytic Conversion of Methylbutynol

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Murad Alsawalha ◽  
Elaref Ratemi

This current article demonstrates how X-ray fluorescence spectroscopy (XRF) was employed to reveal the major constituents of a sample of natural grey Saudi kaolin. The XRF results showed that it contained 52.90 wt.% silica together with 14.84 wt.% alumina. Additionally, this paper presents a study on the effect of holding times (i.e., 6, 12, 18, and 24 h) using pyrrole adsorption and methylbutynol test reaction (MBOH) on the Saudi grey kaolin (raw material). Temperature-programmed desorption of pyrrole (pyrrole-TPD) results indicated that increases in thermal conductivity detector (TCD) signals are directly proportional to increases in the heat activation holding time. Notably, a raw Saudi grey kaolin sample heated at a holding time of twenty-four hours resulted in the most intense TCD signal. Further, the MBOH transformations produced 3-methyl-3-buten-1-yne (MBYNE), as the main product, indicating the dehydration of MBOH due to the acidic sites of Saudi grey kaolin. The basic catalysis route was operative at the beginning of the reaction as acetone was observed only during the initial thirty-five minutes of the reaction then later dispersed entirely. Its disappearance is attributed to the high silica content of the test sample.

2015 ◽  
Vol 663 ◽  
pp. 94-104 ◽  
Author(s):  
M.T. Cotes-Palomino ◽  
Carmen Martínez-García ◽  
Dolores Eliche-Quesada ◽  
Luis Pérez-Villarejo

The industrial activities are responsible for the production of large amounts of solid wastes, which, so far, have found scarce reuse alternative. Clay-based materials show a natural forgiveness towards the incorporation of a wide variety of wastes. This study reported the changes in technological properties of clay-based mixture normally used in the production of bricks, due to the additions of a spent diatomite earth (SDE) discarded by the beer filtration process in the brewing industry. Samples containing 0-10 wt % SDE were extruded and sintered in air in an electric furnace (950 °C, for 3 h). SDE thanks to their organic substances content, during their combustion, act as pore forming agent and providing an energy support in the brick firing process. Also, the waste, because of its high silica content can act as a silica carrier. The results obtained showed that SDE, added in a percentage of 3 wt % to a brick formulation, had better influence with respect to control bricks containing only clay, improves the mechanical properties (compressive strength around 45 MPa) with a bulk density reduction of about of 2%. However, the incorporation of waste in percentage of 7 and 10 wt % had a negative effect due to increased porosity fundamentally open pores generated in the clay body by the combustion of SDE waste, leading to water suction, water absorption and compressive strength values that do not fall within the range specified by bricks UNE standards. Therefore, SDE can thus advantageously used in lower amounts (3 wt %) as silica carrier and in lower proportion as pore agent in clay bricks, with the potential to reduce fuel and natural ceramic raw material consumption, as well as, landfill costs.


2020 ◽  
Vol 202 ◽  
pp. 05008
Author(s):  
Dian Agus Widiarso ◽  
Roynaldo Lumbanbatu ◽  
Vergania Nurlita Putri ◽  
Jenian Marin

The research area was the exposed extruded igneous lava rock in Clering which became the mining location of PT Semarang Mineral Pembangunan in Clering, Donorejo, Jepara with an area of ± 11 ha. This study aims to identify and determine the composition of andesite minerals by macroscopic and microscopic, the main oxide compound data, the use of andesite in industrial sector. The lithology consisted of andesite lava textured, plagioclase, leucite, clinopyroxene, sanidine as phenocryst and ground mass in the form of microlithic andesite lava as a trachytic texture. The hardness of lithology tends to be more moderate, it is considered unsuitable for building foundations. Andesite and tuff in the study area are currently being mined to be used as raw material for glass because of high silica content. In the industrial sector, the feldspar minerals for flux glass, and ceramic raw materials with standard of PT Semarang Mineral Pembangunan and SNI ISO 14703: 2011, 1147-1984 and SNI ISO 12543: 2011. The lithology tuff can be utilized in the manufacturing of ceramics due to high silica and felspar content. The lithology andesite can be utilized as rocks flour in the manufacturing of fertilizer due to high natrium, potassium, and magnesium content.


1965 ◽  
Vol 60 ◽  
pp. 225-247 ◽  
Author(s):  
Colin Renfrew ◽  
J. R. Cann ◽  
J. E. Dixon

Obsidian to the Greeks was no more than a semi-precious stone, black and shiny, suitable for mirrors or exotic ornaments. But to their predecessors in the Aegean through five millenia it was an important raw material for the manufacture of tools and weapons. Sharper and more abundant than flint, more easily worked and cheaper than copper, it was not displaced entirely even by the use of bronze, which was always an expensive material, there being no source of tin in the Aegean. Only when knowledge of iron-working was brought to the Aegean coasts did obsidian fall from its position as an important raw material to that of a curiosity.Huge quantities of obsidian are to be found lying about the surface of most prehistoric sites in south Greece—any farmer or shepherd will tell of the ‘little razors’ to be found on his land. But its occurrence in nature is very unusual since it is found exclusively in regions of recent volcanic activity, and then only when certain conditions exist, such as a high silica content in the lava of the volcano. Every single piece found in mainland Greece had to be imported from overseas, a process implying competent geological knowledge, skill in sailing and navigation, and perhaps social organization, to a considerable degree. It is the earliest trade in the world for which we have concrete evidence.


Author(s):  
Adhi Setiawan ◽  
Jihan Nabillah Hanun ◽  
Ahmad Erlan Afiuddin

The relatively high silica content in bagasse ash can be used as raw material for making zeolite. Zeolite can be used as a heavy metal adsorbent in industrial wastewater treatment. This study aims to synthesize zeolite from bagasse ash and to apply zeolite as an adsorbent of Cu(II) in a continuous system reactor. The effects of contact time, zeolite size, and concentration of Cu(II) solution on the removal efficiency of metals have been studied in this research. The synthesis of zeolite was carried out using the hydrothermal method at 100°C for 7 hours. The synthesized zeolite was characterized using SEM-EDX, XRD, FTIR, and BET The adsorption process was carried out using a continuous reactor with a flow rate of 0.4 L/min and flowed for 60 minutes with sampling at 15-minute intervals. The zeolite size used was 100 and 200 mesh. The results of SEM-EDX analysis showed that Zeolite has an irregular morphology and contains Si at 35.15%. The XRD results show that the zeolite crystallinity is relatively low. The specific surface area of zeolite at size 100 mesh and 200 mesh were 439.48 m2 /g and 697.76 m2/g respectively. The best Cu(II) waste adsorption test results were obtained under zeolite conditions with a particle size of 200 mesh, the concentration of Cu(II) wastewater of 25 mg/L, and an operational time of 60 minutes with a removal efficiency of Cu(II) of 41.57%


Author(s):  
Maciej Trejda ◽  
Magdalena Drobnik ◽  
Ardian Nurwita

AbstractMesoporous silica of SBA-15 type was modified for the first time with 3-(trihydroxysiyl)-1-propanesulfonic acid (TPS) by post-synthesis modification involving microwave or conventional heating in order to generate the Brønsted acidic centers on the material surface. The samples structure and composition were examined by low temperature N2 adsorption/desorption, XRD, HRTEM, elemental and thermal analyses. The surface properties were evaluated by esterification of acetic acid with n-hexanol used as the test reaction. A much higher efficiency of TPS species incorporation was reached with the application of microwave radiation for 1 h than conventional modification for 24 h. It was found that the structure of mesoporous support was preserved after modification using both methods applied in this study. Materials obtained with the use of microwave radiation showed a superior catalytic activity and high stability.


Author(s):  
Vahid Zabihi ◽  
Mohammad Hasan Eikani ◽  
Mehdi Ardjmand ◽  
Seyed Mahdi Latifi ◽  
Alireza Salehirad

Abstract One of the most significant aspects in selective catalytic reduction (SCR) of nitrogen oxides (NOx) is developing suitable catalysts by which the process occurs in a favorable way. At the present work SCR reaction by ammonia (NH3-SCR) was conducted using Co-Mn spinel and its composite with Fe-Mn spinel, as nanocatalysts. The nanocatalysts were fabricated through liquid routes and then their physicochemical properties such as phase composition, degree of agglomeration, particle size distribution, specific surface area and also surface acidic sites have been investigated by X-ray diffraction, Field Emission Scanning Electron Microscope, Energy-dispersive X-ray spectroscopy, energy dispersive spectroscopy mapping, Brunauer–Emmett–Teller, temperature-programmed reduction (H2-TPR) and temperature-programmed desorption of ammonia (NH3-TPD) analysis techniques. The catalytic activity tests in a temperature window of 150–400 °C and gas hourly space velocities of 10,000, 18,000 and 30,000 h−1 revealed that almost in all studied conditions, CoMn2O4/FeMn2O4 nanocomposite exhibited better performance in SCR reaction than CoMn2O4 spinel.


2014 ◽  
Vol 953-954 ◽  
pp. 1035-1039
Author(s):  
Li Qun Wang ◽  
Zhong Bo Yi ◽  
Zhong Xiang Wei

Aimed at improving the utilization of pulverized coal, high-temperature heat pipe technology was introduced into lignite carbonization.Under the design of power of 10kw semi-industrial pulverized coal carbonization test equipment, Fugu lignite coal as raw material to investigate the operating characteristics of the device and carbonization characteristics. Experimental result shows that the high temperature heat pipes heat steadily and meet the temperature requirement of low-temperature carbonization. With the extension of the holding time, the semi-coke fixed carbon content increasing, but volatile matter vice versa, however, holding time above 60 minutes, the effect of carbonization is not obvious, and the best carbonization time is 30 ~ 60 minutes. The length of the holding time has little effect on gas composition, the content of H2 and CH4 are relatively higher than the rest gas, (H2 + CH4) gas accounted for 70% of the total, the heating value remains at 18.76 ~ 19.22MJ/m3, belongs to medium-high value gas, could provide for industrial and civilian use.


2020 ◽  
Vol 63 (15-18) ◽  
pp. 1446-1462 ◽  
Author(s):  
Kathryn L. MacIntosh ◽  
Simon K. Beaumont

AbstractFurfural is a key bioderived platform molecule, and its hydrogenation affords access to a number of important chemical intermediates that can act as “drop-in” replacements to those derived from crude oil or novel alternatives with desirable properties. Here, the vapour phase hydrogenation of furfural to furfuryl alcohol at 180 °C over standard impregnated nickel catalysts is reported and contrasted with the same reaction over copper chromite. Whilst the selectivity to furfuryl alcohol of the unmodified nickel catalysts is much lower than for copper chromite as expected, the activity of the nickel catalysts in the vapour phase is significantly higher, and the deactivation profile remarkably similar. In the case of the supported nickel catalysts, possible contribution to the deactivation by acidic sites on the catalyst support is discounted based on the similarity of deactivation kinetics on Ni/SiO2 with those seen for less acidic Ni/TiO2 and Ni/CeO2. Powder X-ray diffraction is used to exclude sintering as a primary deactivation pathway. Significant coking of the catalyst (~ 30 wt% over 16 h) is observed using temperature programmed oxidation. This, in combination with the solvent extraction analysis and infrared spectroscopy of the coked catalysts points to deactivation by polymeric condensation products of (reactant or) products and hydrocarbon like coke. These findings pave the way for targeted modification of nickel catalysts to use for this important biofeedstock-to-chemicals transformation.


2018 ◽  
Vol 777 ◽  
pp. 564-568 ◽  
Author(s):  
Long He ◽  
Jin Shi Li ◽  
Mei Hua Chen ◽  
Yan Yang ◽  
Xin Peng Lou ◽  
...  

A high-performance quartz sand insulation brick was prepared by using low grade quartz sand under different sintering process conditions. The optimum sintering process conditions were obtained by analyzing the relationship between microstructure and sintering process. Through the compounding, pulping, forming, drying and sintering processes, and the performance test of the porous brick, the following conclusions can be drawn, the comprehensive performance in all aspects, the porosity is similar, the preferred high compressive strength conditions, in order to get a best The bonding point, brick body sintering temperature of 1150 °C, porosity of 74.56%, compressive strength of 2.1 MPa of porous brick, and the pores are smooth, more uniform distribution. With the prolonging of the holding time, the porosity of the porous brick is reduced, and the performance is 1h, the porosity is 77.22% and the compressive strength is 2.05 MPa. When the raw material ratio is 60% quartz sand, 30wt% kaolin, calcium carbonate 9.6wt%, foaming agent 0.4wt%, water ratio 0.9 holding time at 1h sintering at 1150°C can get better porosity and compressive strength of the insulation brick. The porous material was sintered at 1150 °C, the content of foaming agent was 0.2wt%, the ratio of water to material was 0.9, and the compressive pressure and porosity were the better.


2016 ◽  
Vol 842 ◽  
pp. 43-52 ◽  
Author(s):  
Viktor Malau ◽  
Latif Arifudin

Vickers microindentation hardness test has been applied for a long time to determine the mechanical properties of a small volume of samples. The procedure of this hardness test consists of using a constant load on a rigid indenter and measuring the dimensions of the indenter residual impression (indentation imprint) on the surface of the sample tested after loading and unloading. The objective of this research is to characterize the mechanical properties and material constants of HQ (High Quality) 705 alloy steel mainly its VHN (Vickers Hardness Number) and tensile strength before and after quenching and tempering heat treatments. The characterization is based on Vickers microhardness dependence load curves.Quenching treatment was performed in a furnace by heating the samples at austenite temperature of 850 o C with holding time of two hours and then the samples were rapidly cooled in oil bath. Tempering processes were conducted by heating again the quenching samples to temperatures of 150, 200, 250, 300, 350, 400, 450, 500, 550 and 600 o C with holding time of two hours for each sample. Finally, all samples were slowly cooled in atmospheric temperature. The mechanical properties of samples were characterized by using Vickers microhardness dependence load curves.The results show that VHN (Vickers Hardness Number) depends on indentation load and VHN increases with increment of load for indentation load lower than 5 N. VHN is almost constant for indentation load greater than 5 N. The raw material (without heat treatment) has the VHN and tensile strength of 3413 MPa and 1050.61 MPa respectively and the quenched samples have the VHN and tensile strength of 5407 and 1861 MPa respectively. The Vickers hardness and tensile strength decrease with the increment of tempering temperatures. The higher tempering temperature produces lower hardness and tensile strength. The raw material tensile strength of 1058.8 MPa obtained by tensile test is comparable to its tensile strength of 1050.61 MPa obtained by Vickers indentation. This result indicates that Vickers microindentation is valid to use for evaluating the tensile strength of HQ 705 alloy steel.


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