Effect of Potassium Element Content and Crystal Form of Ammonium Tetramolybdate and Reduction Conditions on Properties of Molybdenum Powder

2020 ◽  
Vol 12 (9) ◽  
pp. 1323-1331
Author(s):  
Yan-Fang Chen ◽  
Jing-Pei Xie ◽  
Dou-Qin Ma
Keyword(s):  
Particle Size ◽  
Mixed Crystal ◽  
Great Influence ◽  
Crystal Form ◽  
Raw Material ◽  
Element Content ◽  
Molybdenum Powder ◽  
High Potassium ◽  
Hydrogen Flow

As the raw material for producing molybdenum products, the quality of molybdenum powder such as purity, microstructure, particle size and distribution, has great influence on the microstructure of molybdenum products, which will affect its performance. In this study, the effect of potassium element content and crystal form of ammonium tetramolybdate and reduction conditions on the properties of molybdenum powder was studied. The results show that under the same reduction conditions, the particle size of molybdenum powder obtained by the reduction of high potassium ammonium tetramebolybdate is larger than that obtained by the reduction of low potassium ammonium tetramebolybdate. The particle size distribution of molybdenum powder obtained by the reduction of ammonium tetramebolybdate with mixed crystal form (α-type and β-type) is wider, while that obtained by the reduction of ammonium tetramebolybdate with single crystal form (β-type) is narrower and the particle size is more uniform. The higher the reduction temperature is and the lower the hydrogen flow rate is, the larger the particle size of molybdenum powder will be. The agglomeration degree of molybdenum prepared by β-type ammonium tetramolybdate is lighter than that prepared by ammonium tetramolybdate with mixed crystal form (α-type and β-type), and its sieving rate is higher.

scholarly journals Pembuatan Biodiesel dengan Cara Adsorpsi dan Transesterifikasi Dari Minyak Goreng Bekas

2016 ◽  
Vol 2 (1) ◽  
pp. 71-80
Author(s):  
Lisa Adhani ◽  
Isalmi Aziz ◽  
Siti Nurbayti ◽  
Christie Adi Octavia
Keyword(s):  
Particle Size ◽  
Adsorption Process ◽  
Acid Value ◽  
Raw Material ◽  
Optimal Conditions ◽  
Cooking Oil ◽  
Used Cooking Oil ◽  
Adsorption Processes ◽  
Oil Adsorption

Used cooking oil can be used as raw material for biodiesel, but the levels of free fatty acids (Free Fatty Acid, FFA) is quite high. It is necessary for pretreatment in the form of the adsorption process to reduce levels of FFA. This study aims to determine the optimal conditions of adsorption process and determine the quality of biodiesel produced from adsorption processes and transesterification. Natural zeolites are used as adsorbents activated beforehand using ammonium chloride, calcined and heated to obtain H-zeolite. Furthermore, the adsorption process optimization includes the time, the adsorbent concentration, temperature and particle size. The oil that is already in the adsorption catalyst is reacted with methanol and KOH to obtain biodiesel. The optimum adsorption conditions obtained at the time of 90 minutes, the concentration of H-zeolite 12%, temperature 90 ° C, and a particle size of 0.2 mm that can lower FFA levels from 3.2% to 1.1%. Biodiesel produced meets the quality requirements of SNI 04-7182-2006 with a water content of 0.02%, a density of 857.60 kg / m3, the acid value of 0.29 mg-KOH / g, iodine number 15.71, saponification 168 , 02 and cetane index of 75.62. Compounds contained in biodiesel are methyl 9-octadecanoic (49.45%), methyl heksadekanoat (20.79%), and methyl 9,12oktaekanoat 9.12 (18.87%). Keywords: Biodiesel, used cooking oil, adsorption, transesterification, H-zeolitDOI: http://dx.doi.org/10.15408/jkv.v2i1.3107

Preparation of Superfine Molybdenum Powder by Reduction Process

2009 ◽  
Vol 620-622 ◽  
pp. 723-726
Author(s):  
Xiang Yang Chen ◽  
Chun Yang Bu ◽  
Xin Zhe Lan ◽  
Xin Rui Zhao
Keyword(s):  
Particle Size ◽  
Flow Rate ◽  
Molybdenum Trioxide ◽  
Reduction Process ◽  
Reduction Reaction ◽  
Molybdenum Powder ◽  
Hydrogen Flow Rate ◽  
Optimal Process ◽  
Hydrogen Flow ◽  
Lower Temperature

The principle and process of producing molybdenum powder via reduction reaction of molybdenum trioxide at lower temperature in a N2-H2 system were researched. The effects of hydrogen concentration, temperature, and volatilization rate of molybdenum trioxide on particle size were analyzed. The experimental results showed that the optimal process parameters were 770°C-790°C in 60min when the hydrogen flow rate was 700mL/min. Particle size of superfine molybdenum powder was less than 4μm. The concentrations of hydrogen, temperature and volatilization rate of molybdenum trioxide have great effect on the particle size of superfine molybdenum powder.

scholarly journals PEMBUATAN BRIKET DARI KULIT KAKAO MENGGUNAKAN PEREKAT KULIT UBI KAYU

2017 ◽  
Vol 6 (3) ◽  
pp. 21-27
Author(s):  
Rosta Natalia Sinaga ◽  
Rosdanelli Hasibuan
Keyword(s):  
Particle Size ◽  
Temperature Variation ◽  
Compaction Pressure ◽  
Strength Test ◽  
Raw Material ◽  
Effect Of Temperature ◽  
Fixed Carbon ◽  
Carbonization Process

This study aims to determine the effect of temperature variation carbonization, carbonization time and adhesive variation to charcoal characteristics of cocoa skin using cassava skin adhesive. Briquette is usually made using binder. Binder can embed charcoal each other to form strong and compact briquettes. Some other variables beside binder that influence the quality of briquettes include raw material, compacting presseure and carbonization process. This research used cocoa leather as raw material with cassava skin leaves as binder. All variables affect the content of fixed carbon of the briquettes that influence the caloricvalue of the briquettes. The caloricvalue is the most important factor for determining the quality of the briquettes. In this research, the highest caloricvalue of the briquettes was 4.375 cal/g. It was achieved when cocoa leather were carbonized by method 1 with compaction pressure of 85 kg/cm2 and binderconcentration of 15% where as raw material with  particle size of 100 mesh. The caloricvalue of the  briquettes was still very low and did not meet the qualification of Indonesian standard for briquettes. Based on the strength test, cassava skin leaves couldn’t be used as briquette’s binder. The produced briquettes that used cassava skin leaves as binder had soft structure and easily destroyed.

Influence of raw material particle size on quality of pellets

2008 ◽  
Vol 35 (5) ◽  
pp. 327-337 ◽  
Author(s):  
T. Umadevi ◽  
M. G. Sampath Kumar ◽  
Suresh Kumar ◽  
C. S. Gururaj Prasad ◽  
M. Ranjan
Keyword(s):  
Particle Size ◽  
Raw Material ◽  
Material Particle

scholarly journals Effect of raw materials on drug release from developed Ciprofloxacin tablets

1970 ◽  
Vol 2 (2) ◽  
pp. 8-15
Author(s):  
Heyam Saad Ali ◽  
Junaid Aslam ◽  
Bazigah Rasool ◽  
Saeed Ahemad Khan ◽  
Alaa Agondi
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Raw Materials ◽  
Great Influence ◽  
Storage Conditions ◽  
Raw Material ◽  
Dissolution Behavior ◽  
Granular Form ◽  
Key Words Ciprofloxacin ◽  
Tablet Formulations

The present study was undertaken to assess and evaluate the effect of two parameters on tablet formulation of Ciprofloxacin: a) particle size of raw material and b) storage conditions of both raw material and finished product. The raw materials were two commercial products, coarse (RM1) and fine (RM2) and locally produced granular form (RM3) prepared from RM2. Three tablet formulations were prepared from the raw materials and designated as F1, F2 and F3. The formulation F1 were prepared from RM1, F2 from RM2 by slugging and F3 from RM3 by direct compression. The raw materials and finished products were then subjected to assessment of the different parameters at the time of production and after storage for three month. The particle size distribution for the raw materials was found to be < 100, 100 – 250 and > 250 μm for RM2, RM1 and RM3, respectively. The moisture uptake at 25°C and 4°C under 75% RH was found to be the highest for the fine powder raw material (RM2), however, the developed granular form RM3 showed the least uptake. Moreover, F2 did not attain 80% dissolution after storage of 3 month. The F1 and F3 formulation passed the dissolution test after storage of 3 month, hence, F3 showed the highest value of dissolution (82%) in 30 minutes. The physicochemical properties of raw materials, storage conditions, and manufacturing techniques were found to exert a great influence over the dissolution behavior of Ciprofloxacin tablet formulations.  Key words: Ciprofloxacin tablets; dissolution behavior; physicochemical properties; storage conditionsDOI: 10.3329/sjps.v2i2.5819Stamford Journal of Pharmaceutical Sciences Vol.2(2) 2009: 8-15

Effects of Standoff Distance and Particle Size on Quality of NiCoCrAlY Coating by Cold Spraying

2014 ◽  
Vol 513-517 ◽  
pp. 265-268
Author(s):  
Sheng Qiang Feng ◽  
Bing Ma ◽  
Xiu Ling Wang ◽  
Guang Liu ◽  
Zi Yun Zheng ◽  
...  
Keyword(s):  
Particle Size ◽  
Dynamic Property ◽  
Great Influence ◽  
Cold Spraying ◽  
Standoff Distance ◽  
Cold Gas Dynamic Spraying ◽  
Coating Quality ◽  
Gas Dynamic ◽  
Two Parameters

According to the gas dynamic property of cold spraying, the distance from the outside of nozzle to the substrate has great influence on the coating quality including the thickness of coating and the deposition effeciency. Meanwhile, the effects of particle size on coating quality are of the utmost importance. The influences of two parameters above on the quality of the NiCoCrAlY coating on the magnesium substrate by the experiments of the cold gas dynamic spraying were discussed in this study. The results of the experiments showed that, based on the fact that other parameters were not changed, when the standoff distance was more than 50mm, there were no complete coatings on the surface of the substrate, and its thickness was asymmetrical. When the standoff distance was 25mm, the thickness was homogeneous, and the oxygen content was only 1.3%. Also, when the particle size was 5~50μm, the coating quality was better.

Storage Problems of Poplar Chips from Short Rotation Plantations with Special Emphasis on Fungal Development

2012 ◽  
Vol 8 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Zsuzsanna Horváth ◽  
Béla Marosvölgyi ◽  
Christine Idler ◽  
Ralf Pecenka ◽  
Hannes Lenz
Keyword(s):  
Particle Size ◽  
Health Risk ◽  
Dry Matter ◽  
Ph Value ◽  
Wood Chips ◽  
Raw Material ◽  
Special Focus ◽  
Fungal Development ◽  
Short Rotation ◽  
Fungal Particles

Abstract - There are several problems in storing wood chips freshly harvested from short rotation plantations, which result in quality losses as well as in dry matter and energy losses. The factors influencing the degradation of raw material are examined in this paper with special focus on fungal development. An excessive growth of fungi is connected to dry matter losses and also to an increased health risk during raw material handling. The following factors were measured during 6 months storage of poplar wood chips depending on particle size: box temperature, moisture content, pH-value, appearance of fungi in the storage and the concentration of fungal particles in the air. The results show a close connection between particle size, temperature and attack of fungi. During the storage mesophilic and termophilic species of the genera Alternaria, Aspergillus, Cladosporium, Mucor and Penicillium appeared. The concentration of fungal particles is the highest for fine chips and decreases in bigger particles. There was a special focus on the investigation of the properties of coarse chips (G 50), which represent a good compromise between handling, storage losses and health risk due to fungal development.

TECHNOLOGICAL ASPECTS OF HIGH QUALITY RAW MATERIAL OBTAINING FOR PECTIN PRODUCTION

1970 ◽  
pp. 47-50
Author(s):  
I. A. Ilina ◽  
I. A. Machneva ◽  
E. S. Bakun
Keyword(s):  
Raw Materials ◽  
Thermal Characteristics ◽  
Environmental Safety ◽  
Raw Material ◽  
High Quality ◽  
Temperature Conductivity ◽  
Drying Temperature ◽  
Plant Raw Materials ◽  
Gel Forming Ability

  The article is devoted to the study of the chemical composition, physical and thermal-pfysical characteristics of damp apple pomaces and the identifying patterns of influence of drying temperature the functional composition and gel-forming ability of pectin. The research is aimed at obtaining initial data for the subsequent calculation of the main technological, hydro-mechanical, thermal, structural and economic characteristics of devices for drying the plant raw materials, ensuring the environmental safety and high quality of pectin-containing raw materials, the reducing heat and energy costs. As a result of the study of the thermal characteristics of apple pomaces, the critical points (temperature conductivity – 16.5 x 10-8 m2/s, thermal conductivity – 0.28 W/m K, heat capacity – 1627 j/(kg K)) at a humidity of 56 % are determined, which characterizing the transition from the extraction of weakly bound moisture to the extraction of moisture with strong bonds (colloidal, adsorption). It was found that the pomaces obtained from apples of late ripening have a higher content of solids (21-23 %), soluble pectin and protopectin (2.5-4.5 %). Dried pomaces obtained from apple varieties of late ripening contain up to 25 % pectin, which allow us to recommend them as a source of raw materials for the production of pectin. The optimum modes of preliminary washing of raw materials are offered, allowing to the remove the ballast substances as much as possible. It is established that when the drying temperature increases, the destructive processes are catalyzed: the strength of the pectin jelly and the uronide component and the degree of pectin esterification are reduced. The optimum drying temperature of damp apple pomaces is 80 0C, at which the quality of pectin extracted from the dried raw materials is maintained as much as possible. It is shown that the most effective for the pectin production is a fraction with a particle size of 3-5 mm, which allow us to extract up to 71 % of pectin from raw materials.

Physico-Chemical Aspects of the Influence of Raw Material Components on the Quality of Ceramic Brick

2019 ◽  
Vol 777 (12) ◽  
pp. 37-42
Author(s):  
G.Yu. SHAGIGALIN ◽  
◽  
P.A. FEDOROV ◽  
L.N. LOMAKINA ◽  
◽  
...  
Keyword(s):  
Raw Material ◽  
Ceramic Brick ◽  
Physico Chemical
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