Eggshell waste to produce building lime: calcium oxide reactivity, industrial, environmental and economic implications

2018 ◽  
Vol 51 (5) ◽  
Author(s):  
Eduardo Ferraz ◽  
José A. F. Gamelas ◽  
João Coroado ◽  
Carlos Monteiro ◽  
Fernando Rocha
2022 ◽  
Vol 128 (1) ◽  
Author(s):  
Nurul Afiqah Mohamad Yamin ◽  
Mohd Hafiz Mohd Zaid ◽  
Khamirul Amin Matori ◽  
Josephine Liew Ying Chyi ◽  
Siti Norul Fadhilah Zalamin ◽  
...  

2022 ◽  
Vol 10 (4) ◽  
pp. 1137-1151
Author(s):  
Ajchara Imkum Putkham ◽  
Suwanan Chuakham ◽  
Yuwadee Chaiyachet ◽  
Tanapon Suwansopa ◽  
Apipong Putkham

2015 ◽  
Vol 754-755 ◽  
pp. 171-175 ◽  
Author(s):  
Razi Ahmad ◽  
Rohazriny Rohim ◽  
Naimah Ibrahim

The widespread usage of commercial calcium oxide (CaO) may lead to the depletion due to its non-renewable resources. CaO from eggshell waste has been studied to replace commercial CaO as it is cheaper and reduce cost of production. The objective of this study was to characterize CaO from waste eggshell. Raw eggshell was analyzed by thermal gravimetric analyzer (TGA) to obtain calcination temperature. The raw eggshell and calcined eggshell were characterized by x-ray fluorescence (XRF) and Fourier transform infrared (FTIR) spectroscopy to obtain elemental composition and functional group distribution. The morphologies of eggshell structures were determined by scanning electron microscope (SEM). TGA showed that the suitable temperature for calcination was 900oC. XRF and FTIR results showed that calcium carbonate (CaCO3) in the raw eggshell had been transformed to CaO. The irregular shape of raw eggshell also had been changed to regular shape for calcined eggshell.


2021 ◽  
Vol 904 ◽  
pp. 419-426
Author(s):  
Suwanan Chuakham ◽  
Apipong Putkham ◽  
Ajchara Imkum Putkham ◽  
Sukaranan Kanokwan

Quick lime or calcium oxide has attracted significant attention as a sustainable material to be used as fillers and catalysts in a broad range of industries. The quick lime derived from calcination of eggshell waste in a laboratory-scale rotary furnace is reported in this study. The eggshell waste was prepared by washing several times, drying in the sun, grinding and sieving through a 250 micrometers sieve size. Calcination of the sieved eggshells waste was conducted in a single zone rotary tube furnace at 800 °C with 5 degree slope and at 1 rpm. Both physical and chemical properties of the calcium oxide derived from the calcination of eggshell waste were systematically investigated by various scientific instruments. The results from powder X-Ray Diffraction (PXRD) and X-Ray Fluorescence: (XRF) showed that most of the calcium carbonate in the eggshell waste was thermally transformed to nano-calcium oxide with mean crystallite size of 47.5 nm and with a purity of 97.8%. The results from this study indicated the optimum conditions and the possibility for mass production of nano-calcium oxide via rotary furnace and have shown that the obtained nano-calcium oxide is comparable to the commercial chemical.


2020 ◽  
Vol 998 ◽  
pp. 90-95
Author(s):  
Apipong Putkham ◽  
Somchai Ladhan ◽  
Ajchara Imkum Putkham

Surface area and particle size are significant properties of a catalyst that determine the reaction rate of the heterogeneous catalyst. In this research, calcium oxide derived from industrial eggshell waste was synthesized by thermal decomposition method under air-atmosphere. The obtained eggshell waste was washed, dried, and ground to 420 μm followed by calcination of the ground eggshell in different conditions including calcination temperature (800 to 900 °C) and holding time (1 to 4 hours). Changes of pore structure and the median particle size diameter of the obtained calcium oxides were systematically investigated by various scientific instruments. Results from powder X-ray diffractometer (PXRD) indicated that the calcium oxide can be obtained after calcination at both 800 and at 900°C. Laser diffractometer shows that median particle size diameter of calcium oxide significantly decreased by about 76-95 % with increasing of both calcination temperature and holding time. Additionally, specific surface area of calcium oxides determined by N2 adsorption experiment at-195 °C shows that surface area of calcium oxide dramatically decreased (37-84 %) with increasing both calcination temperature from 800 to 900 °C and calcination time from 1 to 4 hours. These results indicated that both calcination temperature and time play an important role in the shrinkage of pores of calcium oxide. Higher calcination temperature and longer holding time induce more shrinkage of pore leading to smaller particle size diameter and lower surface area of the calcium oxide catalyst.


1965 ◽  
Vol 21 (3) ◽  
pp. 113-118
Author(s):  
Louis T. Rader

2016 ◽  
Vol 13 (2) ◽  
pp. 1-19
Author(s):  
Ndwakhulu Tshishonga

This article examines the socio-economic implications that the controversial sub-culture of skhothane has on the development or underdevelopment of youth at Ekurhuleni and surrounding townships. It interrogates skhothane within the post-modern expressive youth culture. In the township(s) of Ekurhuleni, skhothane is regarded not only as a controversial sub-culture but also as a lifestyle whereby young people compete in acquiring material goods with the ultimate purpose of destroying them. This practice co-exists alongside youth unemployment and underdevelopment which is exacerbated by poverty, rising unemployment and gross inequalities. The author argues that the practice of skhothane sub-culture does not only undermine the policies and programmes aimed at the socio-economic upliftment of young people, but turns the youth into materialistic consumers. In this article, young people are viewed as victims of post-modern lifestyles who are socialised under an intergenerational culture of poverty and underdevelopment. It uses primary data from selected interviews with skhothane members and general members of local communities and secondary sources from books, accredited journals and newspapers.


2020 ◽  
Vol 32 (2) ◽  
pp. 229-234
Author(s):  
Benjamin Kolb ◽  
John Large ◽  
Stuart Watson ◽  
Glyn Smurthwaite

The authors present a technical note for a prone positioning system developed to facilitate cervical extension osteotomy for ankylosing spondylitis in the presence of severe deformity and frailty. Chin-on-chest deformity represents one of the most debilitating changes of ankylosing spondylitis. Where the chin-brow angle approaches or exceeds 90°, prone positioning becomes problematic due to the fixed position of the head. Furthermore, the challenge is compounded where physiological deconditioning leads to frailty, and the side effects of medical therapies decrease muscle mass and skin quality. Conventional prone positioning equipment is not able to cater to all patients. A versatile system was developed using a 3D reconstruction to enable a positioning simulation and verification tool. The tool was used to comprehensively plan the perioperative episode, including spatial orientation and associated equipment. Three-dimensional printing was used to manufacture a bespoke positioning device that precisely matched the contours of the patient, reducing contact pressure and risk of skin injury. The authors were able to safely facilitate surgery for a patient whose deformity and frailty may otherwise have precluded this possibility. The system has potential safety and economic implications that may be of significant utility to other institutions engaging in complex spinal surgery.


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