Effects of particle size on flame structures through corn starch dust explosions

2017 ◽  
Vol 50 ◽  
pp. 7-14 ◽  
Author(s):  
Hongming Zhang ◽  
Xianfeng Chen ◽  
Ying Zhang ◽  
Yi Niu ◽  
Bihe Yuan ◽  
...  
Keyword(s):  
Particle Size ◽  
Corn Starch ◽  
Dust Explosions ◽  
Flame Structures

scholarly journals The Characteristics of Iron Ore Slimes and Their Influence on The Flotation Process

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 675
Author(s):  
Neymayer Pereira Lima ◽  
Klaydison Silva ◽  
Thiago Souza ◽  
Lev Filippov
Keyword(s):  
Particle Size ◽  
Iron Ore ◽  
Corn Starch ◽  
Reverse Flotation ◽  
Flotation Process ◽  
Froth Stability ◽  
Iron Ore Slime ◽  
Iron Ore Slimes ◽  
Main Effects

The flotation has been successfully applied to process the iron ore for the particle size (Ps) from 10 µm up to 150 µm. The presence of the slimes (Ps < 10 µm) is harmful on the reverse flotation of quartz, so they are usually prior removed by hydrocyclones. The main effects of the presence of slimes on the flotation are related to the increase on reagents consumption, the froth stability, and decrease on the selectivity. The lower floatability of coarse quartz particles (+74 µm) combined with the presence of slimes, even in small quantities, drastically affect the flotation response. This paper shows a study of characterization of a typical iron ore slime, aiming to create a better understanding of its role on the concentration by flotation. The main characteristics of typical slimes from the Iron Ore Quadrangle in Brazil are the presence of almost 70% of hematite, 25% of quartz, and 5% of kaolinite, as the main silicates gangue minerals. Furthermore, the particle size distribution revealed that 80% of the hematite and the kaolinite are below 20 µm. The affinity between the ultrafine kaolinite of the slimes with the corn starch is harmful to the reverse flotation of quartz, as the starch has an important depressing action over the hematite. The presence of 20% of hematite −20 µm decreased the recovery to the froth of quartz + 74 µm from 97% to 62%, where the slimes coating seems to be the main responsible.

Effects of Micropores on Processing and Properties of Porous Irons

2017 ◽  
Vol 863 ◽  
pp. 26-32
Author(s):  
Ming Zhou Su ◽  
Hui Meng Wang ◽  
Chang Chen
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Corn Starch ◽  
Sintering Temperature ◽  
Starch Content ◽  
Volumetric Shrinkage ◽  
Small Particle Size ◽  
Compressive Properties ◽  
Different Temperatures ◽  
Powder Metallurgy Route

Porous irons with only micropores were produced through powder metallurgy route. Corn starch of small particle size (5-15μm) was utilized to regulate the densification of green compacts. The structural and mechanical properties of porous irons sintered at different temperatures were evaluated. The porosities increased with increasing the starch content, which reduced compressive strength and increased volumetric shrinkage. The compressive yield stress increased with increasing sintering temperature. It was also found that the effect of sintering temperature on the microstructure and compressive properties was more obvious when green compacts were less densified. Moreover, volumetric shrinkage of porous irons without adding starch remains in a quite low level for different sintering temperatures.

Impacts of Acid Treatment on the Characteristics of Native Corn Starch Granules

2011 ◽  
Vol 221 ◽  
pp. 72-77 ◽  
Author(s):  
Xin Jin ◽  
Shuan Qing Hou ◽  
Xiao Xu Sha ◽  
Liang Yu
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Acid Treatment ◽  
Corn Starch ◽  
Average Particle Size ◽  
Peak Temperature ◽  
Average Particle ◽  
Starch Granules ◽  
Acid Modification ◽  
Before And After

Native corn starches were acid-treated at 53 °C for hours in HCl aqueous solution. The peak temperature (Tp) and heat of gelatinization (ΔHgel) before and after treatments were determined. The average particle size, TG and viscosity were measured. The results showed that the viscosity of corn starch decreased from 630mPa to 4.6mPa after acid treatment for 6h. The average particle size decreased and ΔHgel decreased obviously after acid modification.

scholarly journals Application of an Enhanced Version of Recursive Operability Analysis for Combustible Dusts Risk Assessment

2020 ◽  
Vol 17 (9) ◽  
pp. 3078
Author(s):  
Marco Barozzi ◽  
Sabrina Copelli ◽  
Martina Silvia Scotton ◽  
Vincenzo Torretta
Keyword(s):  
Risk Assessment ◽  
Corn Starch ◽  
Logical Structure ◽  
Critical Issue ◽  
Sequence Diagrams ◽  
Chemical Safety ◽  
Fault Trees ◽  
Sugar Refinery ◽  
Dust Explosions ◽  
Application Fields

Organic dust explosions were and are still today a critical issue in the food, pharmaceutical, and fine chemical industry. Materials such as flour, corn starch, sugar and APIs represent a cause of severe accidents. In this framework, we investigated a modified version of Recursive Operability Analysis−Incidental Sequence Diagrams (ROA–ISD), called ROA Plus−ISD, specifically tailored to describe industrial processes involving organic combustible dusts. Compared to more classical techniques such as Hazard and Operability (HazOp), ROA−ISD allows for a direct generation of fault trees, providing a useful tool to connect Qualitative with Quantitative Risk Analysis (QRA). ROA Plus−ISD is very similar to ROA−Cause Consequence Diagrams (CCD), which has already proven to be an effective tool to perform both risk assessment on existing plants and reconstructing already occurred accidents, given its logical structure and width of the application fields. In this work, we modified specific parts of the standard ROA−CCD method: (1) the Failure Mode and Operability Analysis (FMEA) database has been structured in order to retrieve the well-known explosion pentagon (for dusts) and all the instruments, devices, apparatuses and controllers typical of industries which process organic dusts; (2) a new comprehensive list of process variables has been compiled. In this way, it is possible to tailor the information required for the generation of the fault trees concerning top events involving mainly dust explosions and fires. This method has been implemented in order to reconstruct the dynamics of the February 2008 Imperial Sugar refinery plant accident (Port Wentworth, GA, USA). Results demonstrated the applicability of the enhanced method by highlighting the criticalities of the process already showed by a previously detailed reconstruction performed by the Chemical Safety Board.

Activation of Corn Starch and Effect of the Activation on its Reactivity

2012 ◽  
Vol 549 ◽  
pp. 183-187 ◽  
Author(s):  
Yan Wang ◽  
Jia Ying Xin ◽  
Tie Liu ◽  
Kai Lin ◽  
Chao Yue Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Water Solubility ◽  
Corn Starch ◽  
Cold Water ◽  
Molecular Level ◽  
Chemical Reactivity ◽  
Level Structure ◽  
Average Particle Size ◽  
Average Particle ◽  
Structure And Morphology

Native corn starch (NS) was activated by treatment with NaOH /Urea /H2O solution at low temperature to improve its chemical reactivity. Effects of the activation on the molecular level structure and morphology of the corn starch were investigated by mean of SEM. It was found that the average particle size of activated corn starch (AS) decreased to nanometer level, smaller than those of NS. The cold water solubility (CWS) has been increased from 0.45% to 96.4%. Effects of the activation on reactivity of the corn starches were investigated by analyzing the influences of the activation on degrees of substitutions (DS) of the esterifications. The DS of AS was higher than that of NS, from 0 to 0.1578, which indicated that NaOH/urea activation enhanced the chemical reaction activity of corn starch.

scholarly journals Physicochemical Properties and Resistant Starch Content of Corn Tortilla Flours Refrigerated at Different Storage Times

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 469
Author(s):  
Isela Rojas-Molina ◽  
Monsserrat Mendoza-Avila ◽  
María de los Ángeles Cornejo-Villegas ◽  
Alicia Del Real-López ◽  
Eric Rivera-Muñoz ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Physicochemical Properties ◽  
Size Distribution ◽  
Resistant Starch ◽  
Water Solubility ◽  
Corn Starch ◽  
Starch Content ◽  
Type I ◽  
Corn Tortilla

The tortilla is a foodstuff that has a short shelf-life, causing great losses to the industry. The objective of this work was to evaluate, for the first time, the physicochemical properties and resistant starch (RS) content of flours. These were obtained from nixtamalized corn tortillas made with traditional and industrial (commercial) methods, stored at 4 °C for 7, 15, and 30 days. The flours were characterized by measuring particle size distribution, color, water absorption index (WAI), water solubility index (WSI), viscosity, calcium, and RS content. Additionally, chemical proximate analysis, scanning electron microscopy (SEM), and thermal analysis were conducted. Storage at 4 °C increased the friability of tortillas and shifted the particle size distribution toward a greater content of coarse particles in corn tortilla flours. The commercial corn tortilla flours showed higher WAI and WSI values than the traditional corn tortilla flours. On the other hand, the traditional corn tortilla flours exhibited higher RS content values than commercial corn tortilla flours as well as peak viscosity. X-ray diffractograms revealed the presence of amylose-lipid complexes (RS5) in experimental samples. The thermograms evidenced three endotherms corresponding to corn starch gelatinization and melting of type I and type II amylose–lipid complexes.

Modelling the effect of particle size on dust explosions

2010 ◽  
Vol 65 (2) ◽  
pp. 772-779 ◽  
Author(s):  
A. Di Benedetto ◽  
P. Russo ◽  
P. Amyotte ◽  
N. Marchand
Keyword(s):  
Particle Size ◽  
Effect Of Particle Size ◽  
Dust Explosions

scholarly journals EVALUATION OF POWDER PROPERTIES FROM THE SEED COAT OF TINGUI (Magonia pubescens) AS AN EXCIPIENT FOR SEED PELLETING

2007 ◽  
Vol 29 (67) ◽  
Author(s):  
Antonio Zenon Antunes Teixeira
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Seed Coat ◽  
Corn Starch ◽  
Hydroxypropyl Methylcellulose ◽  
Fluorescence Analysis ◽  
Flow Properties ◽  
X Ray ◽  
Tap Density ◽  
Powder Properties

The aim of this study was to investigate the physical properties of the seed coat of Tingui (Magoniapubescens) in order to evaluate the performance of this polysaccharide as an excipient for seedpelleting. The analysis was emphasized to the flow properties including particle size, particle sizedistribution, density and moisture content of the substance. The results were compared tocommercial excipients including Microcrystalline cellulose (MCC PH 101 and SMCC), Hydroxypropyl methylcellulose (HPMC E50), Polyvinil pirrolidone (PVP K29/32), lactose andcorn starch. The data showed that Tingui was found to have bulk and tap density close to HPMCand corn starch. Particle size and its distribution were fit to HPMC and PVP; however, Tingui hadmoisture content quite close to SMCC and HPMC. In general, Tingui exhibited the free-flowproperties comparable to HPMC and PVP. Energy dispersive X-ray fluorescence analysis confirmedthat the seed coat of Tingui contains elements (K, Ca, Si and Fe) composition.

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