scholarly journals Recovery of Yttrium Oxide from Titanium-Aluminium based wastes

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Srećko Stopić ◽  
Sebastian Kallabis ◽  
Bernd Friedrich
Keyword(s):  
Yttrium Oxide ◽  
Ceramic Industry ◽  
Fine Fraction ◽  
Acid Precipitation ◽  
Dissolution Time ◽  
Combined Method ◽  
Reaction Parameters ◽  
Electronic Filters ◽  
Secondary Materials ◽  
Titanium Aluminium

Yttrium belongs to the rare earth elements and critical metals.Yttrium oxide is mostly used in fluoroscent lamps, production ofelectrodes, in electronic filters, lasers, superconductors and asadditives in various titanium-aluminium materials to improve theirproperties. Recovery of yttrium oxide from secondary sourcessuch as red mud, coatings from ceramic industry and phosphors isextremely important. The main aim of this study is to examine theselective recovery of yttrium oxide from Al-Ti based secondarymaterials using one combined method based mostly on leachingfor selective recovery of yttrium containing: crashing and grindingof materials, sieving, leaching of chosen fine fraction withhydrochloric acid, precipitation with oxalic acid in order to producea pure yttrium oxalate, filtration and a final thermal decompositionof yttrium oxalate. The present study summarized mostly theinfluence of different reaction parameters such as leachingtemperature, time and concentration of hydrochloric acid onyttrium dissolution from Al-Ti based secondary materials. Anincrease of dissolution time and temperature increases yttriumdissolution. An increase of pressure from an atmospheric pressureto 0.5 MPa at 150°C leads to the maximum dissolution of yttrium(about 98.6 %). The final produced yttrium oxide after thermaldecomposition of yttrium oxalate was analyzed using SEM andEDS-analysis.

scholarly journals Characterization and components separation of corn stover by alkali and hydrogen peroxide treatments

2015 ◽  
Vol 17 (2) ◽  
pp. 89-95
Author(s):  
Li Cong ◽  
Zhang Li ◽  
Zhang Guanqun ◽  
Xu Jianguo ◽  
Zhang Long
Keyword(s):  
Corn Stover ◽  
Acid Precipitation ◽  
Solvent System ◽  
Dissolution Time ◽  
Components Separation ◽  
Ethanol Extraction ◽  
Recovery Yield ◽  
Lignin Recovery ◽  
Ft Ir ◽  
Single Factor Experiment

Abstract The dissolution of corn stover in alkaline solvent system composed of NaOH-H2O2 was reported and the separation of its ingredients combined with acid precipitation, ethanol extraction was proposed. It is proven that the residual after alkali solvent was cellulose, the filtrate by the acid precipitation of the liquor was lignin, the solid by the ethanol extraction of the liquor was hemicellulose. The optimum dissolution conditions were determined by single-factor experiment as follows: the concentration of H2O2 5.0%, pH 11.5, dissolution temperature 60°C, dissolution time 3.0 h, the ratio of liquid to solid 30 mL/g. And chemical analysis were employed to determine the purity of the components separated. The structure of the components separated were identifi ed by FT-IR, SEM, XRD and NMR. The cellulose recovery yield can achieve to 84.2% and lignin recovery yield is 86.6%, the hemicellulose recovery yield is 96.7%. After recycling the solvent 3 times, the recovery yield of cellulose, lignin and hemicellulose were 82.7, 87.6 and 97.4%, and the purity of cellulose, lignin and hemicellulose were 98.0, 96.5 and 98.7%, respectively.

Long-term variations in individual particle types in the aerosol of Phoenix, Arizona, as determined using automated electron microprobe analysis and multivariate statistical techniques

1993 ◽  
Vol 51 ◽  
pp. 742-743
Author(s):  
Karen A. Katrinak ◽  
James R. Anderson ◽  
Peter R. Buseck
Keyword(s):  
Electron Microprobe ◽  
Fine Fraction ◽  
Coarse Fraction ◽  
Motor Vehicles ◽  
Multivariate Statistical Methods ◽  
Multivariate Statistical ◽  
X Ray ◽  
Mineral Particles ◽  
Anthropogenic Air Pollutants

Aerosol samples were collected in Phoenix, Arizona on eleven dates between July 1989 and April 1990. Elemental compositions were determined for approximately 1000 particles per sample using an electron microprobe with an energy-dispersive x-ray spectrometer. Fine-fraction samples (particle cut size of 1 to 2 μm) were analyzed for each date; coarse-fraction samples were also analyzed for four of the dates.The data were reduced using multivariate statistical methods. Cluster analysis was first used to define 35 particle types. 81% of all fine-fraction particles and 84% of the coarse-fraction particles were assigned to these types, which include mineral, metal-rich, sulfur-rich, and salt categories. "Zero-count" particles, consisting entirely of elements lighter than Na, constitute an additional category and dominate the fine fraction, reflecting the importance of anthropogenic air pollutants such as those emitted by motor vehicles. Si- and Ca-rich mineral particles dominate the coarse fraction and are also numerous in the fine fraction.

Effects of acid precipitation

1982 ◽  
Vol 16 (3) ◽  
pp. 162-169 ◽  
Author(s):  
Norman R. Glass ◽  
Dean E. Arnold ◽  
James N. Galloway ◽  
George R. Hendrey ◽  
Jeffrey J. Lee ◽  
...  
Keyword(s):  
Acid Precipitation

Purification of Antihemophilic Factor (Factor VIII) by Amino Acid Precipitation*

1964 ◽  
Vol 11 (01) ◽  
pp. 064-074 ◽  
Author(s):  
Robert H Wagner ◽  
William D McLester ◽  
Marion Smith ◽  
K. M Brinkhous
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Factor Viii ◽  
Plasma Protein ◽  
Acid Precipitation ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Specific Procedure ◽  
Beta Alanine ◽  
Antihemophilic Factor

Summary1. The use of several amino acids, glycine, alpha-aminobutyric acid, alanine, beta-alanine, and gamma-aminobutyric acid, as plasma protein precipitants is described.2. A specific procedure is detailed for the preparation of canine antihemophilic factor (AHF, Factor VIII) in which glycine, beta-alanine, and gammaaminobutyric acid serve as the protein precipitants.3. Preliminary results are reported for the precipitation of bovine and human AHF with amino acids.

FORMULATION AND DEVELOPMENT OF FAST DISSOLVING TABLET OF METOCLOPRAMIDE: AN ANTI-EMETIC DRUG

2019 ◽  
Vol 8 (6) ◽  
Author(s):  
Avilash Carpenter ◽  
M.K. Gupta ◽  
Neetesh Kumar Jain ◽  
Urvashi Sharma ◽  
Rahul Sisodiya
Keyword(s):  
Mechanical Strength ◽  
Standard Procedure ◽  
Flow Property ◽  
Storage Conditions ◽  
Angle Of Repose ◽  
Dissolution Time ◽  
Disintegration Time ◽  
Powder Blend ◽  
Standard Curve ◽  
The Stability

Aim: The main of the study is to formulate and develop orally disintegrating fast dissolving tablet of Metoclopramide hydrochloride. Material & Methods: Before formulation and development of selected drug, the standard curve in buffer was prepared and absorbance at selected maxima was taken. Then two different disintegrating agents were selected and drug was mixed with disintegrating agents in different ratio. Various Preformulation parameters and evaluation of tablet i.e. disintegration time, dissolution time, friability, hardness, thickness were measured by standard procedure. Result & Discussion: The angle of repose for all the batches prepared. The values were found to be in the range of 30.46 to 36.45, which indicates good flow property for the powder blend according to the USP. The bulk density and tapped density for all the batches varied from 0.49 to 0.54 g/mL and 0.66 to 0.73, respectively. Carr’s index values were found to be in the range of 23.33 to 25.88, which is satisfactory for the powders as well as implies that the blends have good compressibility. Hausner ratio values obtained were in the range of 1.22 to 1.36, which shows a passable flow property for the powder blend based on the USP. The results for tablet thickness and height for all batches was found to range from 4.45 to 4.72 mm and 3.67 to 3.69 mm, respectively. Hardness or breaking force of tablets for all batches was found to range from 32.8 to 36.2 N. Tablet formulations must show good mechanical strength with sufficient hardness in order to handle shipping and transportation. Friability values for all the formulations were found to be in the range of 0.22 % to 0.30 %. Conclusion: Orally disintegrating tablets were compressed in order to have sufficient mechanical strength and integrity to withstand handling, shipping and transportation. The formulation was shown to have a rapid disintegration time that complied with the USP (less than one minute). The data obtained from the stability studies indicated that the orally disintegrating mini-tablets of MTH were stable under different environmental storage conditions. Keywords: Formulation & Development, Fast Dissolving Tablet, Metoclopramide, Anti-Emetic Drug, Oral Disintegrating Tablet

Effects of release modifier on Carvedilol release from Kollidon SR based matrix

2012 ◽  
Vol 1 (8) ◽  
pp. 186 ◽  
Author(s):  
Urmi Das ◽  
Mohammad Salim Hossain
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Microcrystalline Cellulose ◽  
Matrix Tablets ◽  
Dissolution Time ◽  
Release Mechanism ◽  
Matrix Tablet ◽  
Weight Variation ◽  
The Matrix ◽  
Tablet Formulations

<p>Sustained release Carvedilol matrix tablets constituting Kollidon SR were developed in this study in an attempt to investigate the effect of release modifiers on the release profile of Carvedilol from matrix. Three matrix tablet formulations were prepared by direct compression of Kollidon SR in combination with release modifier (HPMC and Microcrystalline Cellulose) and magnesium stearate. Tablets containing only Kollidon SR with the active ingredient demonstrated a rapid rate of drug release. Incorporation of HPMC in the matrix tablet prolonged the release of drug but incorporation of Microcrystalline Cellulose showed superimposable release pattern with an initial burst effect as confirmed by mean dissolution time and Higuchi release rate data. After 7 hours of dissolution, Carvedilol release from the matrix systems were 91.42%, 83.41%, from formulation F1 and F2 respectively. Formulation F3 exhibited 100 % release at 4 hours. All the tablet formulations showed acceptable pharmaco-technical properties and complied with the in-house specifications for tablet weight variation, friability, hardness, thickness, and diameter. Prepared tablets also showed sustained release property for carvedilol. The drug release mechanism from the matrix tablets of F1 and F2 was found to be followed by Fickian and F3 by Non-Fickian mechanism.</p><p>DOI: <a href="http://dx.doi.org/10.3329/icpj.v1i8.11095">http://dx.doi.org/10.3329/icpj.v1i8.11095</a></p> <p>International Current Pharmaceutical Journal 2012, 1(8): 186-192</p>

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