Production of quicklime from Ashaka limestone through calcination process

2021 ◽  
Vol 1 (2) ◽  
pp. 041-048
Author(s):  
Benson Chinweuba Udeh
Keyword(s):  
Particle Size ◽  
Critical Value ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Particle Sizes ◽  
Calcination Process ◽  
Process Effects ◽  
Effects Of Temperature ◽  
The Difference ◽  
The Relationship

This study is on the production of quicklime from Ashaka limestone through calcination process. Effects of temperature, particle size and time on quicklime yield were determined. The experiment was carried out at temperatures of 800, 900, 1000, 1100 and 1200 0C, particle sizes of 80mm, 90mm, 100mm, 300mm and 425mm and times of 0.5hr, 1hr, 2hrs, 3hrs and 4hrs. Analyses of the results showed that quicklime was successfully produced from Ashaka limestone through the calcination process. Quadratic model adequately described the relationship between quicklime yield and calcination factors of temperature, particle size and time. Recorded model F-value of 134.35 implies that the model is significant. The predicted R² of 0.9597 is in reasonable agreement with the adjusted R² of 0.9844; the difference is less than the critical value of 0.2. Optimum yield of 73.48% was obtained at optima operating conditions; temperature of 1000 0C, particle size of 90 µm and time of 3 hrs.

Effects of calcination variables on quicklime yield of Nkalagu limestone

2021 ◽  
Vol 1 (2) ◽  
pp. 012-023
Author(s):  
Benson Chinweuba Udeh ◽  
Chidinma Lovelyn Ani ◽  
Monday Omotioma
Keyword(s):  
Particle Size ◽  
Mineralogical Composition ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Calcination Process ◽  
Plant Equipment ◽  
The Relationship ◽  
Central Composite

Calcination of Nkalagu limestone for the production of agricultural quicklime is presented. It entails improving the quality of limestone through calcination process. Appropriate scientific instruments/techniques (x-ray diffractometer and scanning electron microscopy) were used for the characterization of the uncalcined and calcined limestone samples. Effects of calcination variables on the quicklime yield were examined. Central composite design of design expert software was used to optimize the calcination process. Analyses of the results revealed that calcite was the major limestone’s mineralogical composition. Quadratic model adequately described the relationship between quicklime yield and calcination factors of temperature, particle size and time. Quadratic model adequately described the relationship between quicklime yield and calcination factors of temperature, particle size and time. The optimum yield of 74.00% was obtained at optima operating conditions; temperature of 937.41 0C, particle size of 85.99µm and time of 3.7 hrs. Characteristics of the quicklime showed that the calcination improved the quality of the sample in terms of mineralogical properties. It is recommended that the generated model should be used to develop chemical plant/equipment for limestone calcination process.

scholarly journals MINERAL ABUNDANCE AND PARTICLE SIZE DISTRIBUTION DERIVED FROM IN-SITU SPECTRA MEASUREMENTS OF YUTU ROVER OF CHANG’E-3

2017 ◽  
Vol XLII-3/W1 ◽  
pp. 85-89
Author(s):  
H. Lin ◽  
X. Zhang ◽  
Y. Yang ◽  
X. Wu ◽  
D. Guo
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Landing Site ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Particle Sizes ◽  
The Mean ◽  
The Difference ◽  
Yutu Rover

From geologic perspective, understanding the types, abundance, and size distributions of minerals allows us to address what geologic processes have been active on the lunar and planetary surface. The imaging spectrometer which was carried by the Yutu Rover of Chinese Chang’E-3 mission collected the reflectance at four different sites at the height of ~ 1 m, providing a new insight to understand the lunar surface. The mineral composition and Particle Size Distribution (PSD) of these four sites were derived in this study using a Radiative Transfer Model (RTM) and Sparse Unmixing (SU) algorithm. The endmembers used were clinopyroxene, orthopyroxene, olivine, plagioclase and agglutinate collected from the lunar sample spectral dataset in RELAB. The results show that the agglutinate, clinopyroxene and olivine are the dominant minerals around the landing site. In location Node E, the abundance of agglutinate can reach up to 70 %, and the abundances of clinopyroxene and olivine are around 10 %. The mean particle sizes and the deviations of these endmembers were retrieved. PSDs of all these endmembers are close to normal distribution, and differences exist in the mean particle sizes, indicating the difference of space weathering rate of these endmembers.

scholarly journals Effects of temperature gradient and particle size on self-ignition temperature of low-rank coal excavated from inner Mongolia, China

2019 ◽  
Vol 6 (9) ◽  
pp. 190374 ◽  
Author(s):  
Yongjun Wang ◽  
Xiaoming Zhang ◽  
Hemeng Zhang ◽  
Kyuro Sasaki
Keyword(s):  
Activation Energy ◽  
Particle Size ◽  
Temperature Gradient ◽  
Ignition Temperature ◽  
Coal Particle ◽  
Critical Value ◽  
Low Rank ◽  
Low Rank Coal ◽  
Coal Particles ◽  
Effects Of Temperature

This study investigates the effects of temperature gradient and coal particle size on the critical self-ignition temperature T CSIT of a coal pile packed with low-rank coal using the wire-mesh basket test to estimate T CSIT based on the Frank–Kamenetskii equation. The values of T CSIT , the temperature gradient and the apparent activation energy of different coal pile volumes packed with coal particles of different sizes are measured. The supercriticality or subcriticality of the coal is assessed using a non-dimensional index I HR based on the temperature gradient at the temperature cross-point between coal and ambient temperatures for coal piles with various volumes and particle sizes. The critical value I HRC at the boundary between supercriticality and subcriticality is determined as a function of pile volume. The coal status of supercritical or subcritical can be separated by critical value of I HR as a function of pile volume. Quantitative effects of coal particle size on T CSIT of coal piles are measured for constant pile volume. It can be concluded that a pile packed with smaller coal particles is more likely to undergo spontaneous combustion, while the chemical activation energy is not sensitive to coal particle size. Finally, the effect of coal particle size on T CSIT is represented by the inclusion of an extra term in the equation giving T CSIT for a coal pile.

The Relationship Between Colliery-waste Particle Sizes and Plant Growth

1974 ◽  
Vol 1 (4) ◽  
pp. 281-284 ◽  
Author(s):  
Christopher G. Down
Keyword(s):  
Particle Size ◽  
Plant Growth ◽  
Water Retention ◽  
Size Range ◽  
Growth Period ◽  
Dry Weight ◽  
Particle Sizes ◽  
Small Particles ◽  
The Relationship ◽  
Water Holding

Seed germination and dry-weight production in Lolium perenne were examined in relation to growth on 12-years-old colliery waste separated into seven size-fractions. The size-range was from more than 4,000 μ to less than 125 μ, and the growth period was up to 30 days. Germination percentages after 6 days generally increased with decreasing particle-size, as did dry-weight. Shoot : root ratios also showed an inverse relationship with particle size.After 30 days there was no distinction between dryweights on different particle sizes, except that on the largest fractions it had been found impossible to keep the plants alive. Problems of water-holding capacity are discussed, and the significance of soil particle-size in revegetation work is examined, it being concluded that an admixture of small particles is important for water retention and plant growth.

scholarly journals Integrated Ozonation-Enzymatic Hydrolysis Pretreatment of Sugarcane Bagasse: Enhancement of Sugars Released to Expended Ozone Ratio

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1274 ◽  
Author(s):  
Daryl Rafael Osuna-Laveaga ◽  
Octavio García-Depraect ◽  
Ramiro Vallejo-Rodríguez ◽  
Alberto López-López ◽  
Elizabeth León-Becerril
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sugarcane Bagasse ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Particle Sizes ◽  
Combined Effects ◽  
Sugar Release ◽  
The Relationship ◽  
Ozonation Process

The combined effects of three key ozonation process parameters on the integrated ozonation-enzymatic hydrolysis pretreatment of sugarcane bagasse (SCB) were investigated, with emphasis on the relationship between sugar release and ozone consumption. A lab-scale fixed bed reactor was employed for ozonation at varying ozone doses (50, 75 and 100 mg O3/g SCB), particle sizes (420, 710 and 1000 µm) and moisture contents (30, 45 and 60% w/w) in multifactorial experiments, keeping a residence time of 30 min. The ozonated SCB showed a reduction in the content of acid-insoluble lignin from 26.6 down to 19.1% w/w, while those of cellulose and hemicellulose were retained above 45.5 and 13.6% w/w, with recoveries of 100–89.9 and 83.5–72.7%, respectively. Ozone-assisted enzymatic hydrolysis allowed attaining glucose and xylose yields as high as 45.0 and 37.8%, respectively. The sugars released/ozone expended ratio ranged between 2.3 and 5.7 g sugars/g O3, being the higher value achieved with an applied ozone input of 50 mg O3/g SCB and SCB with 420 µm particle size and 60% moisture. Such operating conditions led to efficient ozone utilization (<2% unreacted ozone) with a yield of 0.29 g sugars/g SCB. Overall, the amount of sugars released relative to the ozone consumed was improved, entailing an estimated cost of ozonation of USD 34.7/ton of SCB, which could enhance the profitability of the process.

The influence of gypsum particle size on pasture response on a sulphur deficient soil

1968 ◽  
Vol 8 (31) ◽  
pp. 203 ◽  
Author(s):  
KD McLachlan ◽  
Marco DG De
Keyword(s):  
Particle Size ◽  
Soil Surface ◽  
Critical Value ◽  
Sulphur Content ◽  
First Year ◽  
Particle Sizes ◽  
Negative Interaction ◽  
Upper Limits ◽  
Main Effect ◽  
Important Variant

The pasture response to four particle sizes of gypsum fertilizer was measured on a sulphur deficient basaltic soil over a three-year period. At a low rate of application, pasture response was inversely related to particle size ; at a higher rate, only the coarsest fraction differed from the other treatments. The reduction in plant sulphur content and uptake with this fraction suggests that particles >5 mm may be approaching the upper limits of usefulness on this soil. In the first year, the negative interaction between particle size and level of gypsum applied showed that particle size may replace level of application in its effect on response. More efficient use of the sulphur in the fertilizer resulted from application of the finer fractions. Separation of particle size effects into those due to rate of solution of sulphur from the compound, and those due to placement through physical distribution over the soil surface, showed that rate of solution of sulphur was the more important variant. Recognition of its influence could lead to prescribing the correct particle size of gypsum for every sulphur deficient soil. The main effect of the applied sulphur was on the clover component of the pasture. The results suggest that a sulphur content of 0.07 per cent in mature plant tops may be a critical value indicating an adequate sulphur supply, and that 5 lb sulphur an acre in the plant tops may be all that is required for maximum clover production.

Spatial and Temporal Patterns in Macrobenthic Stream Diversity

1976 ◽  
Vol 33 (6) ◽  
pp. 1261-1270 ◽  
Author(s):  
Brigitte G. E. de March
Keyword(s):  
Particle Size ◽  
Related Species ◽  
High Variability ◽  
Particle Sizes ◽  
Spatial And Temporal Patterns ◽  
Mean Particle Size ◽  
Faunal Assemblages ◽  
Number Of Species ◽  
Stream Community ◽  
The Relationship

The relationship between the characteristics of a stream community and sediments were studied for 1 yr in a small unpolluted river with a morainal substrate. Recognizable faunal assemblages were associated with silt or silt fill, sand or sand fill, and large boulders. The fauna in sediments of mean particle sizes coarser than sand but finer than boulders was characterized by a high variability due largely to temporal successions of morphologically related species. It was found that the number of species was directly proportional to mean particle size (in [Formula: see text] units) in spring when the sediments were well sorted, but the relationship broke down as the sediment interstices filled in. In late fall when the sediments were badly sorted, the number of species is perhaps more related to the sorting coefficient of the sediments. The relevance of these findings to studies of pollution is discussed.

Effect of Particles Size on the Properties of Nano Core-Shell Ni/TiO2 EMR Fluid

2011 ◽  
Vol 211-212 ◽  
pp. 775-779 ◽  
Author(s):  
Suo Kui Tan ◽  
Xiao Ping Song ◽  
Qiao Li ◽  
Hong Yan Guo ◽  
Song Ji ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Particle Size ◽  
Electromagnetic Field ◽  
Electrorheological Fluid ◽  
Critical Value ◽  
Core Shell ◽  
Fluid Properties ◽  
Shell Particles ◽  
The Relationship ◽  
Er Fluid

By means of mechanical properties test， the relationship among particle size，electric field，magnetic field ,electromagnetic field and shear ratio on the Ni/TiO2/Urea core-shell particles electrorheological fluid properties analyses. It is found that with increasing particle size， the property of electrorheological fluid decreased, and with increasing shear ratio the property of electrorheological fluid increased for same composition ER. At same time, the smaller of particle size, the higher of ER properties, but there is a critical value for shear ratio, the properties of ER is near value for same composition ER fluid. In magnetic field, the properties of ER showed a contrary result, the smaller of particle size, the lower of ER properties，and electromagnetic field make the properties increase.

Lime Brust of Sintering Bricks of Purple Sandy Shale: the Effect of Limestone Particle Size

2011 ◽  
Vol 250-253 ◽  
pp. 46-49
Author(s):  
Zhi Gang Feng ◽  
Zhen Ping Tang ◽  
Hui Juan Li
Keyword(s):  
Particle Size ◽  
Hunan Province ◽  
Particle Sizes ◽  
Sintering Process ◽  
Critical Content ◽  
Production Practice ◽  
Sandy Shale ◽  
Free Cao ◽  
The Relationship

Simulating current sintering process in local brickkilns, Hengyang region, Hunan Province, China, at 800°C, througt indoor sintering experiment on a series of brick samples of purple sandy shale, in which particle sizes of limestone are >-1Φ, >0Φ, >1Φ, >2Φ, >3Φ and >4Φ, respectively, it is concluded that the following: (1) Limestone granularity is a crucial factor affecting the quality of sintering bricks of purple sandy shale. Under different particle sizes, the critical content of limestone causing lime brust of sintering bricks is distinct, and lowers with the increasing in limestone granularity. (2) When limestone granularity is different, its impact way on the quality of sintering bricks is also distinct. The more coarse limestone granularity is, the more concentrative the swelling stress produced by the hydration of free CaO is, the more easily lime brust occurs. On the contrary, the more fine limestone granularity is, the more dispersive the swelling stress is, there is the more help to reduce or eliminate the occurrence of lime brust. (3) In view of the relationship between limestone granularity and the critical content of limestone giving rise to lime brust of sintering bricks, the production practice can be effectively guided.

scholarly journals Comparative Study of Pore Structure Characteristics between Mudstone and Coal under Different Particle Size Conditions

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8435
Author(s):  
Jianguo Zhang ◽  
Xiyuan Li ◽  
Jihong Jiao ◽  
Jianbao Liu ◽  
Feng Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Pore Structure ◽  
Mercury Intrusion Porosimetry ◽  
Coal Bed ◽  
Particle Sizes ◽  
N2 Adsorption ◽  
Structure Characteristics ◽  
Surface Areas ◽  
The Difference ◽  
And Migration

In order to investigate the difference of pore structure characteristics between mudstone and coal under different particle size conditions, samples acquired from Henan province were smashed and screened into three different particle sizes (20–40, 80–100, and >200 mesh) to conduct the experiments, using the high-pressure mercury intrusion porosimetry (MIP) and low-temperature N2 adsorption (LT-N2A) techniques. The results demonstrated that the proportion of open pores or semi-enclosed pores increased, and the pores became preferable contacted each other for both mudstone and coal during the crushing process. These variations of pore structure characteristics in the coal were beneficial to methane storage and migration. The total specific surface areas and pore volumes all showed a tendency of increasing continually for both mudstone and coal, as the particle sizes decreased from the LT-N2A test. The mudstone and coal were non-rigid aggregates with micropores, plate-shaped pores, and slit-shaped pores developed inside. The effect of the crushing process on the pore shape for the mudstone and coal was inappreciable. Moreover, the influence of the particle sizes on the mesopore was the most significant, followed by the macropore; and on the micropore, the influence was negligible for both mudstone and coal. The crushing process only had a significant impact on the pore structure of mudstone with a particle size of less than 100 mesh, while it could still alter the pore structure of coal with a particle size of larger than 100 mesh. It is believed that this work has a significant meaning to explore the diffusion and migration rules of coal-bed methane in coal.

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