scholarly journals Analysis of the Physicochemical and Mineralogical Properties of the Materials Used in the Preparation of Recoblocks

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3626
Author(s):  
María Neftalí Rojas-Valencia ◽  
José Alberto Lopez-López ◽  
Denise Yeazul Fernández-Rojas ◽  
José Manuel Gómez-Soberón ◽  
Mabel Vaca-Mier
Keyword(s):  
Field Tests ◽  
Construction Sector ◽  
X Ray Diffraction ◽  
Construction Waste ◽  
Mineralogical Properties ◽  
Bending Resistance ◽  
Resistance To Stress ◽  
Materials Used ◽  
Physical And Chemical ◽  
Properties Of Soil

The construction sector generates 14,000 t/d of construction waste in Mexico City, these materials do not have real applications and end up accumulating in landfills. This work, the objective of which was to analyze the physicochemical and mineralogical properties of soil and construction waste used in the manufacture of Recoblocks, is divided in five stages. First, the excavation material was submitted to field tests. Physical and chemical tests were then carried out on construction waste. Subsequently, the optimal mixture for making Recoblocks was determined. Next, Recoblocks were evaluated and compared with blocks made with water only, without mucilage of Opuntia ficus, and finally a feasibility study was performed. The X-ray diffraction study showed the presence of plagioclase, minerals that improve bending resistance, hardness, durability, as well as resistance to stress in a material. Compared to blocks manufactured without mucilage, the use of Opuntia ficus mucilage increased the compressive strength of the material by 59%, as well as the erodibility. Recoblocks are an environmentally friendly option because they are based on recycled materials, dried under the sun, which eliminates the use of brick oven. The production cost per unit is just USD 0.19, so it is a viable option as a building material.

Analysis of Technical Suitability of Using Wood Ash in Cement Based Materials

2016 ◽  
Vol 881 ◽  
pp. 341-345
Author(s):  
Valeria Bennack ◽  
L.V.O. Dalla Valentina ◽  
Marilena Valadares Folgueras
Keyword(s):  
Natural Resources ◽  
Combustion Process ◽  
Chemical Properties ◽  
Wood Ash ◽  
Wood Product ◽  
X Ray Diffraction ◽  
Waste Wood ◽  
Cement Based Materials ◽  
Materials Used ◽  
Physical And Chemical

Economic and environmental issues are directly related to industrial processes which, not only employ natural resources but also generate by-products that may impact the environment. In order to achieve sustainable development, reducing the use of natural resources and lowering cost through adequate destination of waste becomes a crucial issue. The aim of this paper is to analyze the suitability of reusing waste (wood ash) resulting from the combustion process at wood product industries for manufacturing cement based materials used in civil engineering. The material assessed is ash from the combustion process of a wood product industry. In this study, physical and chemical properties such as grain size, mineral and chemical composition of this by-product were characterized. Thermal analysis and X-ray diffraction techniques were used for this purpose. Preliminary results show the suitability of using the waste (wood ash) for manufacturing cement based materials

scholarly journals The influence of different fly ash-cement replacement ratios on the pressure drop of a horizontal backfilling pipe

2021 ◽  
Vol 942 (1) ◽  
pp. 012006
Author(s):  
D Wang ◽  
J Zhao ◽  
J Garcia-del-Real ◽  
H Mischo
Keyword(s):  
Fly Ash ◽  
Pressure Drop ◽  
Flow Velocity ◽  
Thermal Power ◽  
X Ray Diffraction ◽  
Replacement Ratio ◽  
Pseudoplastic Fluid ◽  
Materials Used ◽  
Physical And Chemical ◽  
Flow Particle

Abstract Fly ash (FA) is a kind of harmful by-product in thermal power generation plants, and finding a way to enhance the utility of fly ash has been widely discussed among civil engineering and mining sectors. To investigate the possible optimal ratios of replacing usually used bind agent namely Portland cement (PC) with fly ash, this paper designed different test groups with varying PC-FA replacement ratio. To identify the physical and chemical characteristics of mixing materials used to produce the backfilling slurries, a rheological experiment and X-ray diffraction test have been conducted. Rheological tests show all these three replacement ratio groups (60%, 65%, 70% respectively) are yield pseudoplastic fluid. Computational fluid dynamics as an efficient and money-saving method also has been introduced in the present research to duplicate the flow behaviors and calculate the pressure drop (PD) in the backfilling pipe circuits. The simulation results suggested that all these three RR categories experience an increasing tendency in pressure drop with increasing flow velocity, but in the velocity range of 2 m/s - 2.4 m/s, the increasing tendency is gentle until flow velocity reaches 2.6 m/s, the PD increase evidently. Furthermore, when the RR = 65%, the pressure drop is significantly lower than that of RR = 60% or RR = 70% at all the corresponding investigated flow particle sizes have significant impact on the pressure drop across a pipe and is dependent on solid fraction and flow rate and velocities. Therefore, we can conclude that a proper dosage of FA in mixing backfilling slurries can reduce pressure drop obviously and thereby decrease the expenses in bind agent. Given the FA’s significant effect on pressure drop, and comprehensive considering the backfilling capacity and backfilling cost, the combination of RR = 65% and velocity = 2.6 m/s is optimum.

scholarly journals The Influence Of NO/O2 On The NOx Storage Properties Over A Pt-Ba-Ce/γ-Al2O3 Catalyst

2019 ◽  
Vol 17 (1) ◽  
pp. 1459-1465
Author(s):  
Xuedong Feng ◽  
Jing Yi ◽  
Peng Luo
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
No Oxidation ◽  
Test Results ◽  
X Ray Diffraction ◽  
Storage Performance ◽  
Transmission Electron ◽  
Temperature Programmed ◽  
Physical And Chemical ◽  
Al2o3 Catalyst

AbstractWith the purpose of studying the influence of NO/O2 on the NOx storage activity, a Pt-Ba-Ce/γ-Al2O3 catalyst was synthesized by an acid-aided sol-gel method. The physical and chemical properties of the catalyst were characterized by X-ray diffraction (XRD) and Transmission Electron Microscope (TEM) methods. The results showed that the composition of the catalyst was well-crystallized and the crystalline size of CeO2 (111) was about 5.7 nm. The mechanism of NO and NO2 storage and NOx temperature programmed desorption (NO-TPD) experiments were investigated to evaluate the NOx storage capacity of the catalyst. Pt-Ba-Ce/γ-Al2O3 catalyst presented the supreme NOx storage performance at 350℃, and the maximum value reached to 668.8 μmol / gcat. Compared with O2-free condition, NO oxidation to NO2 by O2 had a beneficial effect on the storage performance of NOx. NO-TPD test results showed that the NOx species stored on the catalyst surface still kept relatively stable even below 350℃.

Micro-Ribbons and Micro-Wires Silica Synthesis Using Bottom-Top Technique

2020 ◽  
Vol 1008 ◽  
pp. 33-38
Author(s):  
Marwa Nabil ◽  
Hussien A. Motaweh
Keyword(s):  
Selection Process ◽  
Chemical Properties ◽  
Industrial Applications ◽  
Preparation Process ◽  
Pure Silica ◽  
One Step ◽  
Materials Used ◽  
Sonication Technique ◽  
Silica Synthesis ◽  
Physical And Chemical

Silica is one of the most important materials used in many industries. The basic factor on which the selection process depends is the structural form, which is dependent on the various physical and chemical properties. One of the common methods in preparing pure silica is that it needs more than one stage to ensure the preparation process completion. The goal of this research is studying the nucleation technique (Bottom-top) for micro-wires and micro-ribbons silica synthesis. The silica nanoand microstructures are prepared using a duality (one step); a combination of alkali chemical etching process {potassium hydroxide (3 wt %) and n-propanol (30 Vol %)} and the ultra-sonication technique. In addition, the used materials in the preparation process are environmentally friendly materials that produce no harmful residues. The powder product is characterized using XRD, FTIR, Raman spectrum and SEM for determining the shape of architectures. The most significant factor of the nucleation mechanism is the sonication time of silica powder production during the dual technique. The product stages are as follows; silica nanoparticles (21-38 nm), nanoclusters silica (46 – 67 nm), micro-wires silica (1.17 – 6.29 μm), and micro-ribbons silica (19.4 – 54.1 μm). It's allowing for use in environmental applications (multiple wastewater purification, multiple uses in air filters, as well as many industrial applications).

Monitoring of Fluctuations in the Physical and Chemical Properties of a High-Calcium Fly Ash

1987 ◽  
Vol 113 ◽  
Author(s):  
Scott Schlorholtz ◽  
Ken Bergeson ◽  
Turgut Demirel
Keyword(s):  
Fly Ash ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Physical And Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
High Calcium ◽  
Physical And Chemical ◽  
And Chemical Properties

ABSTRACTThe physical and chemical properties of fly ash produced at Ottumwa Generating Station have been monitored since April, 1985. The fly ash is produced from burning a low sulfur, sub-bituminous coal obtained from the Powder River Basin near Gillette, Wyoming. One-hundred and sixty samples of fly ash were obtained during the two year period. All of the samples were subjected to physical testing as specified by ASTM C 311. About one-hundred of the samples were also subjected to a series of tests designed to monitor the self-cementing properties of the fly ash. Many of the fly ash samples were subjected to x-ray diffraction and fluorescence analysis to define the mineralogical and chemical composition of the bulk fly ash as a function of sampling date. Hydration products in selected hardened fly ash pastes, were studied by x-ray diffraction and scanning electron microscopy. The studies indicated that power plant operating conditions influenced the compressive strength of the fly ash paste specimens. Mineralogical and morphological studies of the fly ash pastes indicated that stratlingite formation occurred in the highstrength specimens, while ettringite was the major hydration product evident in the low-strength specimens.

scholarly journals STUDY AND ESTIMATION OF THE RATIO OF 137CS AND 40K SPECIFIC ACTIVITIES IN SANDY AND LOAM SOILS / 137CS IR 40K SAVITŲJŲ AKTYVUMŲ SANTYKIŲ TYRIMAS IR VERTINIMAS PRIESMĖLIO IR PRIEMOLIO DIRVOŽEMYJE

2011 ◽  
Vol 3 (5) ◽  
pp. 37-42
Author(s):  
Renata Mikalauskienė ◽  
Donatas Butkus ◽  
Ingrida Pliopaitė Bataitienė
Keyword(s):  
Chemical Properties ◽  
Dry Weight ◽  
Soil Samples ◽  
Physical And Chemical Properties ◽  
Nuclear Testing ◽  
Specific Activities ◽  
Physical And Chemical ◽  
Chernobyl Nuclear Plant ◽  
Properties Of Soil ◽  
And Chemical Properties

The present article describes changes in specific activities and fluctuations in the ratio of natural 40K and artificial 137Cs radionuclides in soil samples taken from different places of Lithuanian territory. The samples of soil have been selected from the districts polluted after the accident in Chernobyl nuclear plant performing nuclear testing operations. The study has established the main physical and chemical properties of soil samples and their impact on the concentration of 40K activities. 137Cs/40K specific activities in soil have been observed under the dry weight of the sample that varied from 0.0034 to 0.0240. The results of the study could be used for establishing and estimating 137Csand 40K transfer in the system “soil-plant”. Santrauka Straipsnyje nagrinėjama gamtinės (40K) ir dirbtinės (137Cs) kilmės radionuklidų savitųjų aktyvumų ir jų santykio kaita skirtinguose Lietuvos teritorijos dirvožemiuose. Dirvožemio mėginiai parinkti iš vietovių, kurios buvo labiau užterštos po Černobylio atominės elektrinės avarijos ir buvusių branduolinių bandymų. Tyrimo metu nustatytos pagrindinės fizinės cheminės dirvožemio savybės ir jų poveikis 40K aktyvumų koncentracijai. 137Csir 40K savitieji aktyvumai dirvožemyje tirti esant sausam mėginio svoriui. 137Cs savitieji aktyvumai sausame dirvožemyje svyravo nuo 1,1±1,0 iki 14,3±0,9 Bq/kg, o 40K savitieji aktyvumai – nuo 326±29 iki 740±15 Bq/kg. 137Csir 40K savitųjų aktyvumų santykis skirtingų vietovių dirvožemiuose kito nuo 0,0034 iki 0,0240 Bq/kg. Tyrimo rezultatai gali būti panaudoti, nustatant ir įvertinant 137Csir 40K pernašą sistemoje dirvožemis–augalai.

Fabrication of 239/238Pu-Zirconolite Ceramic Pellets by Natural Sintering

2003 ◽  
Vol 807 ◽  
Author(s):  
T. Advocat ◽  
F. Jorion ◽  
T. Marcillat ◽  
G. Leturcq ◽  
X. Deschanels ◽  
...  
Keyword(s):  
Grain Size ◽  
Radioactive Waste ◽  
Nuclear Waste ◽  
Chemical Stability ◽  
Minor Actinides ◽  
Loading Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physical And Chemical ◽  
Inorganic Matrix

ABSTRACTZirconolite is a potential inorganic matrix that is currently investigated in France, in the framework of the 1991 radioactive waste management law, with a view to provide durable containment of the trivalent and tetravalent minor actinides like neptunium, curium, americium and small quantities of unrecyclable plutonium separated from other nuclear waste. To confirm the actinide loading capacity of the zirconolite calcium site and to study the physical and chemical stability of this type of ceramic when subjected to alpha self-irradiation, zirconolite ceramic pellets were fabricated with 10 wt% plutonium oxide (isotope 239 or 238). The 55 pellets are dense (> 93.3% of the theoretical density on average) and free of cracks. They are characterized by a grain size of between 10 and 20 micrometers. X-ray diffraction analyses confirmed the presence of the zirconolite 2M crystalline structure.

Physical Properties of Saltstone: Physical Properties of Saltstone: A Savannah River Plant Waste Form

1984 ◽  
Vol 44 ◽  
Author(s):  
Christine A. Langton
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Field Tests ◽  
Waste Form ◽  
Savannah River ◽  
X Ray Diffraction ◽  
Near Surface ◽  
Leach Rate ◽  
Savannah River Plant ◽  
Water To Cement Ratio

AbstractA cement-based waste form, “saltstone,” has been designed for disposal of Savannah River Plant low-level radioactive salt waste. Laboratory and field tests indicate that this stabilization process greatly reduces the mobility of all of the waste constituents in the surface and near-surface environment. Bulk properties of this material have been tailored with respect to salt leach rate, permeability, and compressive strength. Microstructure and mineralogy were characterized by SEM and x-ray diffraction analyses.Compressive strength was found to increase as the water to cement ratio decreased. Porosity and mean pore size increased with increasing water to cement ratios. Bulk diffusivities of the various ions dissolved in the pore solutions were also found to increase as water to cement ratios increased.

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