scholarly journals Synthesis of Rare-Earth-Based Oxides for the Ceramic Industry: From Laboratory to Pilot Plant

1991 ◽  
Vol 249 ◽  
Author(s):  
U. Balachandran ◽  
S. E. Donris ◽  
M. T. Lanagan ◽  
R. B. Poeppel ◽  
J. M. Tourre ◽  
...  

ABSTRACTA wide variety of compounds, e.g., superconductors, chromites, and manganites, can be synthesized by spray drying a mixture of salts or a combination of salts and sols in a flash dryer. The process ensures good control of stoichiometry, morphology, particle size, and surface area. Appropriate particle-growth and synthesis heat treatments of these fine powders have been conducted, and the resultant powders have been evaluated for possible applications in fuel cells and superconductors. The process has been scaled up to a pilot-plant capacity of ≈40 kg per day.

2021 ◽  
Vol 63 (6) ◽  
pp. 41-44
Author(s):  
Duc Hoan Truong ◽  
◽  
Thuy Phuong Ngo- ◽  
Duc Manh Dinh ◽  
Thanh Tung Dang ◽  
...  

This paper studied the effects of feed properties in spray drying formulation of prototype industrial cracking catalysts at the laboratory scale. The results showed that the pH of the drying feed mainly affected the active phase HY zeolite. At a high pH value, a strongly alkaline medium (pH 14), the HY zeolite structure was completely destroyed, resulting in the cracking catalyst with a low surface area. Hence, the pH of the drying feed should be adjusted to a low value, preferably a slightly acidic medium (pH 3). The solid content mainly affected the particle size of the cracking catalyst. As increasing the solid content in the drying feed, the particle size of the cracking catalysts increased and reached the maximum average value at about 40 μm which corresponded to the solid content of 15 wt.%. At a higher solid content (20 wt.%), the catalyst particle size and surface area tended to decrease. Thus, the solid content of 15 wt.% was considered to be optimal.


Author(s):  
Alvin A. Solomon ◽  
Sean M. McDeavitt ◽  
V. Chandramouli ◽  
S. Anthonysamy ◽  
S. Kuchibhotla ◽  
...  

Spray drying is a physical process of granulating fine powders that is used widely in the chemical, pharmaceutical, ceramic, and food industries. It is generally used to produce flowable fine powders for mechanized processing. Occasionally it is used to fabricate sintered bodies like cemented carbides, and has been used to produce sintered fuel and actinide microspheres [1]. As a physical process, it can be adapted to many powder types and mixtures and thus, has appeal for dispersion nuclear fuels, and waste forms of various compositions. It also permits easy recycling of unused powders, and generates minimal chemical waste streams that can arise in chemical sol/gel processing. On the other hand, the containment of the radioactive powders, present safety challenges that need to be addressed [2]. Detailed formal procedures and methods for characterizing and processing UO2/ThO2 mixtures have been established and approved by the Purdue Radiological Control Committee for (1) ball-milling, (2) viscosity and rheology measurements on slurries, (3) sintering, (4) co-precipitation, (5) particle size analysis using laser scattering, (6) surface area analysis using the BET technique, (7) X-ray diffraction, (8) stoichiometry measurement, (9) zeta potential measurements and (10) ceramographic preparation. The spray drying procedures represented a particular challenge since they deal with the handling of loose powders. Studies were carried out to formulate suitable stable, dense and homogeneous aqueous slurries of urania and thoria powders for the production of urania-thoria microspheres by the spray drying method. The studies included (a) particle size distribution after ball-milling, (b) viscosity, (c) zeta potential, (d) slurry flowability, stability and cleanability, (e) microsphere green strength, and f) effects of organic dispersants on the above properties. After formulating the slurry, U,ThO2 microspheres were produced using a commercial, laboratory-scale spray dryer modified for handling these radioactive materials. The microspheres thus obtained were dried at 473 K for 4 hours, presintered at 1173 K for 2 hours and sintered at 1923 K for 10 hours.


2014 ◽  
Vol 535 ◽  
pp. 725-728 ◽  
Author(s):  
Cheng Lu ◽  
Lin Chen ◽  
Yun Bo Chen ◽  
Yi Jie Gu ◽  
Meng Wang ◽  
...  

LiFePO4/C materials were synthesized by spray-drying using FePO4·2H2O, LiOH·H2O as raw materials, with three kinds of organic carbon sources: soluble starch, crystal sugar and glucose. The particle size, tap density, specific surface area, morphology, structure and electrochemical properties of the LiFePO4/C were tested and analyzed. The results indicate that the organic carbon source has no effect on the phase of LiFePO4, but has a remarkable influence on the tap density and specific surface area of LiFePO4. The LiFePO4/C synthesized with crystal sugar and glucose has higher tap density, smaller particle size and specific surface area. The LiFePO4/C synthesized with the glucose as the carbon source exhibited the most excellent electrochemical performance. The discharge capacities are 160.6, 148.5 and 114.1mAh/g respectively at 0.1C, 1C and 5C. Under low temperature 253K, the discharge capacity is 56.2% of that at 298K with 0.2C.


Author(s):  
Gülsel Yurtdaş Kırımlıoğlu ◽  
Sinan Özer ◽  
Gülay Büyükköroğlu ◽  
Yasemin Yazan

Background: Considering the low ocular bioavailability of conventional formulations used for ocular bacterial infection treatment, there’s a need for designing efficient novel drug delivery systems that may enhance of precorneal retention time and corneal permeability. Aim and Objective: The current research focuses on developing nanosized and non-toxic Eudragit® RL 100 and Kollidon® SR nanoparticles loaded with moxifloxacin hydrochloride (MOX) for its prolonged release to be promising for effective ocular delivery. Methods: In this study, MOX was incorporation was carried out by spray drying method aiming ocular delivery. In vitro characteristics were evaluated in detail with different methods. Results: MOX was successfully incorporated into Eudragit® RL 100 and Kollidon® SR polymeric nanoparticles by spray-drying process. Particle size, zeta potential, entrapment efficiency, particle morphology, thermal, FTIR, XRD and NMR analyses and MOX quantification using HPLC method were carried out to evaluate the nanoparticles prepared. MOX loaded nanoparticles demonstrated nanosized and spherical shape while in vitro release studies demonstrated modified release pattern which followed Korsmeyer-Peppas kinetic model. Following successful incorporation of MOX into the nanoparticles, the formulation (MOX: Eudragit® RL 100, 1:5) (ERL-MOX 2) was selected for further studies by the reason of its better characteristics like cationic zeta potential, smaller particle size, narrow size distribution and more uniform prolonged release pattern. Moreover, ERL-MOX 2 formulation remained stable for 3 months and demonstrated higher cell viability values for MOX. Conclusion: In vitro characterization analyses showed that non-toxic, nano-sized and cationic ERLMOX 2 formulation has the potential of enhancing ocular bioavailability.


Nanoscale ◽  
2021 ◽  
Author(s):  
Gabriela Guida ◽  
Steven Huband ◽  
Marc Walker ◽  
Richard I. Walton ◽  
Paulo C. de Sousa Filho

The mechanisms of a one-pot colloidal conversion of hydroxycarbonate templates into vanadate nanoparticles were investigated, with further correlation of Eu3+ spectroscopic properties to particle size, texture, nanocrystallinity, and defect density.


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