scholarly journals Submicron SiO2 Powder: Characterization and Effects on Properties of Cement-Free Iron Ditch Castables

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Shuiming Cheng ◽  
Huizhong Zhao ◽  
Yu Wang ◽  
Jianxiu Wei ◽  
Jinfeng Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Bending Strength ◽  
Raw Materials ◽  
Rate Of Change ◽  
Free Iron ◽  
New Type ◽  
Sio2 Powder ◽  
Powder Content

Submicron materials are those with particle size diameters between 0.1 and 1 μm. Submicron SiO2 generally refers to SiO2 powder with a D90 < 1 μm (D90 refers to the particle size distribution exhibited by the sample and corresponds, in this case, to 90% of the particles not exceeding a diameter of 1 μm). In this study, a new type of cement-free iron ditch castable was prepared using dense corundum and silicon carbide as the primary raw materials with submicron SiO2 powder as the binder. The effects of submicron SiO2 powder content on the bulk density, apparent porosity, linear rate of change, compressive strength, and bending strength were investigated. The mechanism of action of the submicron SiO2 powder was also investigated by analyzing its microstructure and particle size distribution. The results revealed that (1) the submicron SiO2 powder can be used as the sole bonding agent in the preparation of cement-free iron ditch castables; (2) in comparison to traditional castables, the cement-free castable developed in this study demonstrated strong service performance and high-temperature bending strength.

scholarly journals Phase evolution, characterisation, and performance of cement prepared in an oxy-fuel atmosphere

2016 ◽  
Vol 192 ◽  
pp. 113-124 ◽  
Author(s):  
Liya Zheng ◽  
Thomas P. Hills ◽  
Paul Fennell
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Carbon Capture ◽  
Raw Materials ◽  
Carbon Capture And Storage ◽  
Phase Evolution ◽  
Chemical Compositions ◽  
Phase And Elemental Compositions

Cement manufacture is one of the major contributors (7–10%) to global anthropogenic CO2 emissions. Carbon capture and storage (CCS) has been identified as a vital technology for decarbonising the sector. Oxy-fuel combustion, involving burning fuel in a mixture of recycled CO2 and pure O2 instead of air, makes CO2 capture much easier. Since it combines a theoretically lower energy penalty with an increase in production, it is attractive as a CCS technology in cement plants. However, it is necessary to demonstrate that changes in the clinkering atmosphere do not reduce the quality of the clinker produced. Clinkers were successfully produced in an oxy-fuel atmosphere using only pure oxides as raw materials as well as a mixture of oxides and clay. Then, CEM I cements were prepared by the addition of 5 wt% gypsum to the clinkers. Quantitative XRD and XRF were used to obtain the phase and elemental compositions of the clinkers. The particle size distribution and compressive strength of the cements at 3, 7, 14, and 28 days' ages were tested, and the effect of the particle size distribution on the compressive strength was investigated. Additionally, the compressive strength of the cements produced in oxy-fuel atmospheres was compared with those of the cement produced in air and commercially available CEMEX CEM I. The results show that good-quality cement can be successfully produced in an oxy-fuel atmosphere and it has similar phase and chemical compositions to CEM I. Additionally, it has a comparable compressive strength to the cement produced in air and to commercially available CEMEX CEM I.

Joining of Ceramic Components in the Green State via LPIM

2007 ◽  
Vol 29-30 ◽  
pp. 207-210 ◽  
Author(s):  
Rolf Waesche ◽  
Carl Paulick ◽  
Gabriele Steinborn ◽  
V. Richter ◽  
M. Werner
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Bending Strength ◽  
Ceramic Materials ◽  
Alumina Powder ◽  
Second Phase ◽  
Green State ◽  
Ceramic Components ◽  
Molded Parts

It has been successfully demonstrated that ceramic materials can be joined in the green state without a second phase by using low pressure injection molded parts. The investigation of the joining interface revealed that a high quality interface can be achieved by carefully adjusting the different manufacturing steps. The use of monomodal particle size distribution in the used powder CT3000SG is inferior to a broader particle size distribution obtained by replacing 33% of the finer alumina powder by coarser CT1200SG. In this way the dewaxing process is significantly improved when the wall thickness of the part exceeds 3 mm. The investigation of the mechanical properties of the joined and sintered parts revealed, that the bending strength of the joined specimens achieved about 80 % of the unjoined, monolithic specimens.

scholarly journals Investigation of Microbial Contamination and Physicochemical Properties of Compounded Medications in Pharmacies

2020 ◽  
Vol 26 (1) ◽  
pp. 82-93
Author(s):  
Reihaneh Radmanesh ◽  
◽  
Mohsen Nabi Meybodi ◽  
Vahid Ramezani ◽  
Maryam Akrami ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Microbial Contamination ◽  
Raw Materials ◽  
Chemical Properties ◽  
Pharmaceutical Product ◽  
Physical And Chemical ◽  
Made In ◽  
And Chemical Properties

Aims: Any pharmaceutical product made in pharmacy, hospital or factory may be contaminated with microbes. This contamination can originate from raw materials or during production. Hence, it is important to study the physical and chemical properties and stability of compounded drugs. Methods & Materials: In this study, first a specific sample of prescribed medication was ordered from 63 pharmacies in Yazd, Iran. After collecting the samples, the amount of microbial contamination, viscosity and particle size distribution and their stability were investigated and their results were compared to the standard levels. Findings: Based on the results, 31.7% of the samples had discoloration and 23.8% showed creaming phenomenon. In terms of particle size distribution, 57.1% of the samples had a 20-40 μm particle size and 49.2% had a viscosity equal to 2500-3000 centipoise. Regarding stability, 12.6% of the samples underwnet phase change at 30-40°C. About of the amount of hydroquinone in samples, 35% had acceptable amount. In 23.8% of the samples, fungal infection was observed. Conclusion: Contrary to a popular belief that the compounded medicines produced in pharmacies have microbial contamination, the results of this study showed that the microbial contamination of these compounded medications is low.

scholarly journals Particle Size Distribution of New Type Nanomist Humidifier

10.5109/27368 ◽  
2013 ◽  
Vol 58 (2) ◽  
pp. 365-370
Author(s):  
Duong Van Hung ◽  
Daisuke Hamanaka ◽  
Fumihiko Tanaka ◽  
Toshitaka Uchino
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
New Type

Preparation and Properties of Cross-Linked Polysiloxane Microspheres for Light-Scattering

2017 ◽  
Vol 896 ◽  
pp. 57-61
Author(s):  
Ming Shan Yang ◽  
Peng Wei Yin ◽  
Hong Liang Tong
Keyword(s):  
Particle Size ◽  
Light Scattering ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Ph Value ◽  
Raw Materials ◽  
Narrow Particle Size Distribution ◽  
Vinyl Silane ◽  
Oil Water ◽  
Water Ratio

The narrow particle size distribution of poly (vinyl silicone) microspheres were prepared by the hydrolysis-polycondensation method with vinyl silane (VTMS) as raw materials. And the influences of pH value, oil/water ratio on the morphology, particle size and distribution of the microspheres were studied. The results shows that the particle size of microspheres decrease with the increasing of the PH value of polymerization, and the particle size has no specific linear relationship with the PH value of hydrolysis reaction, while the oil-water ratio is smaller, single particle size distribution is more narrow, more uniform distribution.

Combustion Synthesis of β-SiAlON Using 3D Ball Milling

2017 ◽  
Vol 898 ◽  
pp. 1717-1723 ◽  
Author(s):  
Xue Mei Yi ◽  
Shota Suzuki ◽  
Xiong Zhang Liu ◽  
Ran Guo ◽  
Tomohiro Akiyama
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Combustion Synthesis ◽  
Ball Mill ◽  
Raw Materials ◽  
Raw Material ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Material Particle

Combustion synthesis (CS) of β-SiAlON was conducted using a 3D ball mill, with a focus on the effect of the 2D/3D ball mill premixing conditions on the CS raw material particle size as well as on the yield and grain shape of the final products. The results showed that the particle size distribution of the raw materials was significantly affected by the premixing conditions. Various particle sizes and particle size distributions could easily be obtained by using a 3D mill instead of a 2D mill due to the complex biaxial rotation movement of 3D milling. The particle size was more sensitive to the rotation ratio (vertical spin/horizontal spin, Vv/Vh) than the rotation rate when using 3D milling. Finally, β-SiAlON with less than 5 mass% unreacted Si was obtained using premix milling conditions of 135×200 [vertical spin (rpm) × horizontal spin (rpm)]. The grain shapes of the final products were clearly influenced by the particle size distribution of the raw mixtures.

Research of the Particle Gradation Technology of Components in PBX Explosive Based on CPM Model

2015 ◽  
Vol 727-728 ◽  
pp. 366-369
Author(s):  
Qiu An Huang ◽  
Geng Guang Xu ◽  
Jian Yu Chen
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Relative Error ◽  
Fine Particles ◽  
Raw Materials ◽  
Maximum Value ◽  
Packing Model ◽  
Packing Efficiency ◽  
Compressible Packing Model

Basedon the assumption of related parameters in compressible packing model, thecompressible packing model was used for the calculation of the explosivespacking efficiency. The accuracy of the calculation was verified by experimentsand the relative error was 2.49%. Besides, the influence of content offineparticles and particle size distribution in explosives on stacking efficiencywas discussed. The results show that the stacking efficiency was increasingwith the particle size distribution increasing from 0~300μm to 0~700μm. Thepacking efficiency reached it’s maximum value when we only increased thecontent of fine particles to 40%. Therefore, the packing efficiency has arelation with particle size distribution of raw materials.

scholarly journals Characterization of Minim-Martap Bauxite and Its Extracted Alumina

2018 ◽  
Vol 4 (4) ◽  
pp. 598-600
Author(s):  
Parfait Aristide Zé ◽  
Cornelius Tsamo ◽  
Richard Kamga
Keyword(s):  
Particle Size ◽  
Relative Humidity ◽  
Ir Spectroscopy ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Acid Treatment ◽  
Raw Materials ◽  
Industrial Processes ◽  
Loss On Ignition

Due to their chemical and mineralogical properties bauxites are composites with multiple applications. In this work, the properties of bauxite collected from Minim-Martap and its extracted alumina were evaluated. Alumina was extracted by adapting the Bayer process at laboratory scale while the characteristics of bauxite and alumina were variably characterized by determining the particle size distribution, relative humidity, loss on ignition, pH, EC, CEC, PZC, XRD, IR, and DSC-TGA. These results show that Minim-Martap bauxite gray bauxite with easily extractable alumina. This bauxite is acidic with a pH of 6.05, PZC of 6.91 and CEC of 15 Meq/100 g which is closer to that of kaolinite clays. This result was confirm by XRD which shows two types of kaolinites: Al2Si2O5(OH)4 with 83.24% and H4Al2Si2O9 with 42.47%, mullite Al2.25Si0.75O4.875 with 67.32%, gibbsite (H2SiO4) with 83.92%. The bauxite is hydroscopic as evident from its humidity results. The IR spectroscopy of bauxite and alumina shows the presence of Al-OH and Si-OH which increase with acid treatment. Minim-martap bauxite and its extracted alumina can be used as raw materials for many industrial processes because of the different properties they possess as revealed by this study.

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