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

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.

2021 ◽  
Vol 1 (2) ◽  
pp. 041-048
Author(s):  
Benson Chinweuba Udeh

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.


2021 ◽  
Vol 2 (1) ◽  
pp. 021-029
Author(s):  
Benson Chinweuba Udeh

This study focused on processing of Yandev quicklime for potential amelioration of acidic soil. It involved production of quicklime from the Yandev limestone, characterization and slaking of the quicklime. In a batch process, 10g of the limestone (90mm particle size) was calcined for 3hrs to produce the quicklime. Mineralogical composition of the quicklime was determined by X-ray Diffractometer (XRD), while scanning electron microscope (SEM) was used to examine its surface morphology. The CaO was hydrated for the production of slaked lime (Ca (OH) 2). The slaking process was carried out by digesting CaO in distilled water. During the slaking/hydration process, values of reactivity (rise in temperature) were recorded. Central composite design (CCD) tool of Design Expert Software 11 was used to design the experiment of the slaking process. Quicklime/water ratio, particle size and time were the considered slaking variables, while reactivity was considered as the response. Analysis of the results quicklime is made up of pure calcite with visible pores. Quadratic model adequately described the relationship between reactivity and the considered slaking factors of quicklime/water ratio, particle size and time. Optimum reactivity was obtained as 58.4 0C with the corresponding optimal factors of quicklime/water ratio (0.26 g/ml), particle size (93.0 µm) and time (16.4 minutes). Properties of the slaked lime showed that it is suitable for acidic soil amelioration.


2015 ◽  
Vol 820 ◽  
pp. 24-29
Author(s):  
Alessandra Savazzini dos Reis ◽  
Jailson N. Oliveira ◽  
Viviana P. della Sagrillo ◽  
Francisco R. Valenzuela-Diaz

Structural ceramic quality is particularly related to the quality of the clays. Our aim is to characterize the common clay called Batinga used in the ceramic industry in Colatina - ES, which has a ceramic pole with about twenty companies. Batinga samples were tested for chemical and mineralogical composition, particle size distribution characterization, thermal behavior, optical microscopy, SEM and Atterberg limits. The specimens were shaped, dried at 110oC, burned in industrial furnace and submitted to ceramic test. The results show that the clay presents typical chemical composition of raw clay with significant amount of silica and alumina, besides adequate particle size distribution and mineralogical composition. The high plasticity shown may require high water content in the molding of ceramic roof tiles. The tests yielded results that showed that the clay meets the requirements of the Brazilian standard for structural ceramic.


2018 ◽  
Vol 10 (1) ◽  
pp. 338
Author(s):  
Rachmawati Ramadhana Mustofa ◽  
Iskandarsyah .

Objective: This study aimed to prepare and characterize anti-acne ethosomes using the cold- and thin-layer hydration methods.Methods: A sonication step was included during ethosome preparation to improve the quality of the cold method. Azelaic acid, Phospholipon 90G,ethanol, propylene glycol, and phosphate buffer (pH 7.4) were used in the procedures. Prepared ethosomal suspensions were characterized usingtransmission electron microscopy, particle-size analysis, and spectrophotometry.Results: Ethosomes prepared using the thin-layer hydration method (F1) had small unilamellar vesicles, while those prepared using the cold methodwith 15-min sonication (F4) showed spherical, elliptical, unilamellar, and multilamellar vesicles. F1 ethosomes had a Dmean volume of 648.57±231.26,whereas those prepared using the cold method with 5- (F2), 10- (F3), and 15-min (F4) sonication had Dmean volumes of 2734.04±231.49 nm,948.90±394.52 nm, and 931.69±471.84 nm, respectively. Polydispersity indices of F2, F3, and F4 ethosomes were 0.74±0.21, 0.86±0.05, and 0.91±0.03,respectively, with a poor particle-size distribution, compared to that of F1 (0.39±0.01). Zeta potentials of F1–F4 ethosomes were −38.27±1.72 mV,−23.53±1.04 mV, −31.4±1.04 mV, and −34.3±1.61 mV, respectively. Entrapment efficiencies of F1–F4 ethosomes were 90.71±0.11%, 53.84±3.16%,72.56±0.28%, and 75.11±1.42%, respectively.Conclusion: Anti-acne ethosomes produced using the thin-layer hydration method had superior properties than those produced using the coldmethod with 15-min sonication.


2014 ◽  
Vol 798-799 ◽  
pp. 355-359 ◽  
Author(s):  
Valter Bezerra Dantas ◽  
U.U. Gomes ◽  
A.B. Vital ◽  
G.S. Marinho ◽  
Ariadne de Souza Silva

This paper presents the results of tests for characterization of soil samples collected in Mossoró-RN, UFERSA-RN Campus (5 ° 12'34 .68 "South latitude, 37 ° 19 '5.74 "west longitude), for the purpose of producing soil-cement for the manufacture of pressed blocks. Objective of improving the quality of soil-cement, and provide conditions for the use of the soil making it ideal for the production of soil-cement block. Tests of compaction, particle size analysis, plastic limit, liquid limit and correct particle size, X-ray fluorescence and morphology by scanning electron microscopy (SEM). It was concluded that the soil needs correction particle size, due to the high clay content. The method combined grading, sieving, sedimentation and blooming X-ray as the fastest and most accurate in correcting soil particle size.


2019 ◽  
Vol 4 (9) ◽  
pp. 149-152
Author(s):  
Andrew Ozigagun ◽  
Raphael Biu

Welding is a multi-input multi-output fabrication process, which requires a multi-response optimization technique. In this present work, the effect of heat affected zone and percentage dilution on the quality of Tungsten Inert Gas welded joints was investigated using mild steel plates. The Central Composite Design matrix was adopted to perform the welding experiment and collect the data, thereafter Response Surface Methodology (RSM) models was employed to minimize heat affected zone and percentage dilution with very significant statistical results. The result shows that the quadratic model was the most suitable for the HAZ data and the percentage dilution data with a P-value < 0.05 and R2 value of 88% and 90% for the HAZ and percentage dilution respectively.


2017 ◽  
Vol 1 (T4) ◽  
pp. 241-248
Author(s):  
Loc Cam Luu ◽  
Da Linh Ho ◽  
Phu Chi Hoang ◽  
Tri Nguyen ◽  
Van Thi Thuy Nguyen ◽  
...  

In seafood processing plants, industrial waste water discharge reached virtually the level B (QCVN 11-MT:2015/BTNMT) after using mechanical, physicochemical and biological wastewater treatment methods. However, their COD values (COD = 20-120 mg/L) were not qualified for allowable concentration of discharge requirement - level A (COD ≤ 75 mg/L) in many cases. In this paper, bio-treated seafood waster water was continually treated by TiO2 photocatalyst modified by doping Fe and N to degrade recalcitrant organic pollutants to obtain the A level water which can be resused. TiO2 modified by doping Fe and N were prepared and investigated the physico-chemicalproperties. The results showed that modified TiO2 had a lower band gap and more photoactivity than pure TiO2. Beside that, at the reaction conditions: reaction temperature 25 oC, dissolved oxygen concentration 7.6 mg/L and pH = 7, the optimal concentration of catalysts was determined (1.25 g/L). After 12 hours of treatment, COD removal efficiency on TiO2-Fe and TiO2-N catalysts attained 41.1 % and 64.3 %, respectively, and their COD values reached 49.3 and 29.9 mg/L, correspondingly. After treatment, the quality of waste water discharge met the level A (QCVN 11-MT:2015/BTNMT) and became a safety source for reusing (QCVN 08-MT:2015/BTNMT). In addition, the relationship between the characterization of modifed TiO2 and their activity was characterized.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shakeel Ahmed Soomro ◽  
Kunjie Chen ◽  
Sohail Ahmed Soomro

Rice when harvested normally has a high moisture content of 20–25% which requires immediate drying, reducing its mass loss and preventing it to spoil. This situation is more crucial with the areas under humid tropical conditions, where moisture and temperature mainly play an important role in deteriorating the quality of rough rice. Keeping the importance of quality attributes of rough rice, the study was carried out to assess the effects of low-temperature drying and suggest an optimum condition. Response surface methodology (RSM) with a central composite design was employed to study the effects of variables, i.e., temperature (X1), time (X2), and air velocity (X3) on responses, i.e., head rice yield (HRY), hardness, lightness, and cooking time. The experimental data were fitted to the quadratic model, studying the relationship between independent and dependent variables. The results revealed that the HRY, hardness, lightness, and cooking time increased with increasing variables, whereas for HRY, it particularly increased and then decreased. It was observed that temperature had more influence on the quality of rough rice followed by time and velocity. Results for analysis of variance revealed that the quality aspects of rough rice were significantly (p<0.05) affected by temperature and time, whereas for velocity, it only significantly affected hardness. The optimal drying conditions predicted by RSM for variables were 25°C, 600 min, and 1 m·s−1, and the optimal predicted HRY, hardness, lightness, and cooking time were 73.93%, 38.28 N, 71.40, and 27.58 min respectively. Acceptable values of R2, Adj R2, and nonsignificance of lack of fit demonstrated that the model applied was adequate and can be used for optimization. The study concluded that the RSM with a central composite design was successfully used to study the dependence of quality aspects of rough rice at low temperature and can be utilized by the rice processing industries.


Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 301 ◽  
Author(s):  
Seiya Komurasaki ◽  
Hiroyuki Kajimoto ◽  
Hiroki Ishizuka

Tactile displays have been widely studied for many decades. Although multiple tactile stimuli are more effective to improve the quality of the presented tactile sensation, most tactile displays provide a single tactile stimulus. An integrated tactile display with electrovibration and electrical stimuli is proposed herein. It is expected that vibrational friction, pressure and vibration can be presented at the same time through the tactile display. Also, these stimuli only require electrodes for stimulation. Therefore, the tactile display can be easily miniaturized and densely arrayed on a substrate. In this study, a tactile display is designed and fabricated using the micro-fabrication process. Furthermore, the display is evaluated. First, the relationship between a single stimulus and the perception is investigated. The electrovibration and electrical stimuli have a frequency dependence on perception. Second, whether the multiple stimuli with the electrovibration and electrical stimuli are perceivable by the subjects is also evaluated. The results indicate that the multiple tactile stimuli are perceivable by the subjects. Also, the possibility that the electrovibration and electrical stimuli affect each other is confirmed.


2018 ◽  
Vol 67 ◽  
pp. 03030
Author(s):  
Praswasti P.D.K Wulan ◽  
Juan Octavian Daniel Sidauruk ◽  
Juli Ayu Ningtyas

Variations of the pyrolysis temperature and time are carried out to obtain the correlation between those variables and the number of pyrolysis gases, as well as the yield and quality of produced CNT. PP is pyrolyzed at a temperature range of 525-600°C to produce pyrolizate gases. The flame synthesis method is used to convert PP plastic waste into CNT alongside with the use of wired mesh stainless steel type SS 316 as the substrate. The substrate is pre-treated by oxidative heat treatment at 800°C for 10 minutes before the synthesis to breach the outer chromium layer and make grains on the catalytic surface to enable CNT to grow. Pyrolizate gases are mixed with oxygen flowed from a venturi, so combustion reaction occurs. The combustion gas is flowed to the synthesis reactor to produce CNT at 800°C. Characterization of produced CNT is carried out using XRD, GC-FID, and TEM. The highest yield is obtained at the pyrolysis temperature of 525°C for 45 minutes. While the optimal quality based on the structure, crystalline and particle size is achieved at the pyrolysis temperature of 525°C for 30 minutes which results in CNT with 23.81 nm of average crystallite size and 104.8 nm of particle size.


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