scholarly journals Processing of Yandev quicklime for potential amelioration of acidic soil

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.

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 9 (3) ◽  
pp. 068-076
Author(s):  
Benson Chinweuba Udeh

This is a research report of the effects of process variables on the reactivity of slaked lime produced from Shuk quicklime. It involved the calcination (at temperature of 1000 0C, particle size of 90 µm and time of 3 hrs) of Shuk limestone and subsequent slaking of its quicklime. The quicklime was characterized by x-ray diffractometer (XRD) and scanning electron microscopy (SEM) respectively to determine its mineral content and surface morphology respectively. Effects of process variables (quicklime/water ratio, particle size and time) on the reactivity of the slaked lime were determined. The reactivity was optimized using response surface methodology (RSM). The XRD analysis revealed calcite as the type mineral of the Shuk quicklime. The surface morphology of the quicklime sample showed that the particles are packed together in powdered form with visible pores that will allow passage of water. Reactivity of the lime was influenced by the quicklime/water ratio, particle size and time. Quadratic model appropriately explained the relationship between reactivity and considered slaking factors of quicklime/water ratio, particle size and time. The optimum reactivity value of the slaked lime was obtained as 59.3 oC at quicklime/water ratio of 0.24 g/ml, particle size of 88.2 µm and time of 15.1 minutes.


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.


Author(s):  
Asghar Azizi ◽  
Reza Ghaedrahmati

A response surface method using a central composite design was employed to evaluate, model and optimize the influence of five main factors in the gold cyanidation process. These factors were pH, solid percentage, NaCN concentration, particle size and leaching time. A second-order equation was proposed and developed for the relationship between the gold recoveries and influential factors. The modelling results indicated that the factors influencing the degree of cyanide leaching of gold were in the order of leaching time > NaCN concentration 2 > particle size > pH > NaCN concentration > leaching time 2 > solid percentage × particle size > solid percentage × NaCN concentration > solid percentage. Also, we obtained a coefficient of determination ( R 2 ) greater than 93%, which showed that the developed model was well fitted to the experimental data. In addition, the model equation was individually optimized by using quadratic programming to maximize gold recoveries within the experimental range. The optimum condition was found to be pH 10.11 for the solution, 36.07% for the solids content, 729.56 ppm for the NaCN concentration, 37.52  μ m for the particle size and 23.2 h for the leaching time. Under these conditions, the highest recovery of gold was achieved of approximately 91.5%.


Author(s):  
Caline Leal ◽  
Matheus Nikolaos Carneiro Brunet ◽  
Luciana Amorim ◽  
Francisco Cézar Costa Nogueira ◽  
Waleska Rodrigues Pontes da Costa ◽  
...  

2021 ◽  
Vol 57 (4) ◽  
pp. 333-342
Author(s):  
Trung Huu Nguyen ◽  
Tran Nguyen Minh An ◽  
Mahboob Alam ◽  
Duc Hoai Tran ◽  
Nghi Tran ◽  
...  

The goal of the research is to develop an experimental mathematical model of pan coating process effect on the biodegradable polymer and to determine optimal process parameters. The polymer solution was conducted with phosphated di-starch phosphate, polyvinyl alcohol, and polyacrylic acid and performed as material coating for the controlled-release urea fertilizer. The image analysis method has been used to determine the particle size distribution, Sauter mean diameter of the particle and layer thickness that is novel. The central composite rotatable design has been selected to determine the regression models of the process, which described the relationship between two objective variables as layer thickness, release time with angle of pan, spray flow, and coating time. The statistical analysis results indicate the fitness of model.


1984 ◽  
Vol 19 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Alena Mudroch

Abstract Surface sediment samples obtained at the offshore and nearshore area of Lake Erie were separated into eight different size fractions ranging from <2 µm to 250 µm. The concentration of major elements (Si, Al, Ca, Mg, K, Na, Fe, Mn and P), metals (Zn, Cu, Cr, Ni, V, Co and Pb) and organic matter was determined together with the mineralogical composition and morphology of the particles in each size fraction. The distribution of the metals in the offshore sediment was bimodal with the majority of the metals divided between the 63 to 250 um size fraction which also contained the highest concentration of organic matter (about 20%) and the <4 µm fraction containing up to 60% of clay minerals. However, the metals in the nearshore sediment were associated mainly with the clay minerals.


2020 ◽  
Vol 15 (2) ◽  
pp. 152-165
Author(s):  
Harekrishna Roy ◽  
Sisir Nandi ◽  
Ungarala Pavani ◽  
Uppuluri Lakshmi ◽  
Tamma Saicharan Reddy ◽  
...  

Background: The present study deals with the formulation and optimization of piroxicam fast dissolving tablets and analyzes the impact of an independent variable while selecting the optimized formulation utilizing Quality by Design (QbD) and Box-Behnken Design (BBD). Methods: Seventeen formulations were prepared by direct compression technique by altering the proportion of cross carmellose sodium, spray dried lactose and hydro propyl methyl cellulose (HPMC K4M). The BBD statistical technique was used to optimize formulations and correlate the relationship among all the variables. Also, the powder mixture characteristics and tablet physiochemical properties such as hardness, friability, drug content, Disintegration Time (DT) and dissolution test were determined using 900 ml of 0.1N HCl (pH-1.2) at 37 ± 0.5°C. Results: Significant quadratic model and second order polynomial equations were established using BBD. To find out the relationship between variables and responses, 3D response surface and 2D contour plot was plotted. A perturbation graph was also plotted to identify the deviation of the variables from the mean point. An optimized formula was prepared based on the predicted response and the resulting responses were observed to be close with the predicted value. Conclusion: The optimized formulation with the desired parameter and formulation with variables and responses can be obtained by BBD and could be used in the large experiment with the involvement of a large number of variables and responses.


2010 ◽  
Vol 156-157 ◽  
pp. 1702-1707
Author(s):  
Xiang Wen Cheng ◽  
Jinchao Liu ◽  
Qi Zhi Ding ◽  
Li Ming Song ◽  
Zhan Lin Wang

How to predict the relationship among particle size and among product size, to establish the relationship between the granularity and working parameters in the process of grinding and to determine the optimum operating parameters. With proposing BS squeeze crush model by L. Bass and the idea of roll surface division as the material uneven extrusion force are adopted. Based on field experiments the experimental data is analyzed, the select function and the breakage functions are fitted with MATLAB software, and obtaining their model. The comminution model is determined by the roller division. We obtain the model parameter through the experimental data. Through model analysis shows: the relationship between particle breakage and energy absorption, namely the smaller size of the same power, the lower broken; the breakage diminishes with the decrease of particle size ratio and it will be tending to a small constant when the smaller particle size ratio. The breakage functions rapidly decrease within ratio of between 0.2-0.7. This shows: the energy consumption will rapidly increase when the particle size of less than 0.2 in broken; the selection diminish with the decrease of particle size. Pressure (8-9MPa) should be the most appropriate value.


Sign in / Sign up

Export Citation Format

Share Document