scholarly journals Simple recycling of biowaste eggshells to various calcium phosphates for specific industries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nongnuch Laohavisuti ◽  
Banjong Boonchom ◽  
Wimonmat Boonmee ◽  
Kittichai Chaiseeda ◽  
Somkiat Seesanong

AbstractEgg consumption is very high throughout the world and with it comes enormous amount of waste eggshells. To reduce and utilize these wastes, eggshell wastes were simply transformed to low- or high-purity calcium carbonate grades by washing, crushing, and drying to use as raw materials for producing highly valuable calcium phosphate products. Low-purity calcium carbonate grade was used to prepare triple superphosphate for using in fertilizer industry, whereas high-purity calcium carbonate grade was used to produce dicalcium phosphate dihydrate, monocalcium phosphate monohydrate, and tricalcium phosphate for using in mineral feed and food additive industries. All calcium phosphate samples obtained by simple, rapid, cheap, and environmentally safe method using eggshells and phosphoric acid were identified and their structural phases and impurities were determined by XRF, XRD and FTIR techniques. Thermal behaviors of raw materials and the prepared calcium phosphates excepted tricalcium phosphate were investigated by TG/DTG techniques. The methodologies described here will be useful to manage eggshells by converting them to highly valuable products, which can solve eggshell wastes problem from industries and communities. This finding supports the viewpoint of zero waste operation to produce value-added products for obtaining sustainable development, which may be selected as an alternative way for material recycling and waste management in the future.

2019 ◽  
Vol 9 (6) ◽  
pp. 668-674 ◽  
Author(s):  
Qili Wang ◽  
Mingquan Yu ◽  
Jiannan Gong ◽  
Fengtao Zhang

As one of the major value-added products of coal processing and utilization, coal pitch coke and coal tar pitch are used as raw materials to prepare high-purity graphite. The structure characteristics and properties were measured by experiments. The results show that the high-purity graphite has excellent physical properties: the skeletal density of 1.81–1.91 g/cm3, the Shore hardness of 45.5–66.6 Hs, the flexural strength of 33.0–46.1 MPa, the compressive strength of 65.6–75.8 MPa, the ash content of 67–181 ppm, the thermal expansion coefficient of 3.71–4.11 × 10–6/°C, and the electrical resistivity of 8.72–12.13 μΩ · m. Consequently, coal-based graphite materials have excellent properties and good application prospects in solar energy industry, which is an effective exploration for the transformation and upgrading of Chinese coal industry.


2016 ◽  
Vol 851 ◽  
pp. 8-13
Author(s):  
Nuchnapa Tangboriboon ◽  
Jularpar Suttiprapar

Calcium hydroxyapatite made from duck eggshell react to phosphoric acid with the Ca/P mole ratio 1.67 and calcined at 800º, 900º, and 1000°C for each temperature 2 hr. Duck eggshell is a source of calcium carbonate having high purity content more than 98.101 %w/w and small amount of other metal oxides. Duck eggshell is a bio-material similar to other calcium sources i.e. coral, animal bone, and seashell. There are many advantages of using duck eggshell as a raw material such as abundant, low price, high purity of calcium carbonate content, easy to calcium phosphate formation, biocompatibility, bioactive, non-toxic for human, and the high percentage of ceramic yield 69.73%w/w. In addition, one of the most important advantages is to reduce the amount of duck eggshell waste from household and food industries as environmental conservation. The optimum condition to obtain high purity hydroxyapatite is sintering calcium phosphate at 1000°C for 2 hr. The average particle size, specific surface are, pore diameter, and true density of sample sintered at 1000°C for 2 hr are 39.92 µm, 2.12 m2/g, 98.96 Å, 3.02 g/cm3, respectively, in soft fine white powder. Furthermore, the results obtained by XRF, SEM, and XRD confirmed of sample fired at 1000°C for 2 hr to be calcium hydroxyapatite (HA, Ca10(PO4)6(OH)2) of Ca/P mole ratio 1.67 and small amount of calcium phosphate (β-TCP, Ca3PO4) of Ca/P mole ratio 1.5. Therefore, the duck eggshell is a potentially bio-ceramic material to prepare calcium hydroxyapatite applied for biomedical, bio-dental, and many industries i.e. pharmaceutical, toothpaste, cosmetic, and nutrient food etc.


2014 ◽  
Vol 608 ◽  
pp. 280-286
Author(s):  
Nudthakarn Kosachan ◽  
Angkhana Jaroenworaluck ◽  
Sirithan Jiemsirilers ◽  
Supatra Jinawath ◽  
Ron Stevens

Calcium phosphate cement has been widely used as a bone substitute because of its chemical similarity to natural bone. In this study, calcium phosphate cement was prepared using dicalcium phosphate dihydrate (CaHPO4.2H2O) and calcium carbonate (CaCO3) as starting raw materials. The cement pastes were mixed and the chemistry adjusted with two different aqueous solutions of sodium hydroxide (NaOH) and disodium hydrogen phosphate (Na2HPO4). Concentrations of the solution were varied in the range 0.5 to 5.0 mol/L with the ratio of solid/liquid = 2 g/ml. The cement paste was then poured into a silicone mold having a diameter of 10 mm and a height 15 mm. Setting times for the cement were measured using a Vicat apparatus. XRD, FT-IR, and SEM techniques were used to characterize properties and microstructure of the cement. From the experimental results, it is clear that different concentrations of Na2HPO4 and NaOH have affected the setting times of the cement. The relationship between concentration of NaOH and Na2HPO4 and setting time, including final properties of the cement, is discussed.


2005 ◽  
Vol 04 (04) ◽  
pp. 517-523
Author(s):  
WENJIAN WENG ◽  
YANBO GAO ◽  
LILI PAN ◽  
YANBAO LI ◽  
PIYI DU ◽  
...  

Biodegradable porous materials can serve as a scaffold in tissue engineering. In this work, highly porous nano-calcium phosphate (NCP)/poly(L-lactic acid)(PLLA) composites were prepared by a thermally induced phase separation technique. Five calcium phosphates with different biodegradation rate were selected, i.e. amorphous calcium phosphate, α-tricalcium phosphate, β-tricalcium phosphate and biphasic α/β-tricalcium phosphate. The results showed that the NCP particles could be homogenously incorporated into pore walls; the composites had a porosity of ~90%, and a pore size of ~200 μm. From the point of view of materials science, the obtained porous NCP/PLLA composites demonstrate to have a capability of applying in bone tissue engineering.


2012 ◽  
Vol 610-613 ◽  
pp. 2328-2331 ◽  
Author(s):  
Nan Hee Lee ◽  
Kyu Hong Hwang ◽  
Jong Kook Lee

Biphasic calcium phosphate bioceramics were fabricated from the recycling of bone ash which is mostly used as raw materials of bone china. Precursor calcium phosphate powders were prepared by soaking the commercial bone ash in 0.1 M of NaOH solution at 80°C for 4 h. Calcium phosphate powders was obtained by calcination at 800°C for 1 h to completely remove residual organics. Biphasic calcium phosphate bioceramics which is composed of hydroxyapatite and tricalcium phosphate was fabricated by the sintering of pressed compacts at 1200°C for 1 h under moisture protection. The bone ash derived-biphasic calcium phosphate ceramics consists of mostly HA and small amounts of α-tricalcium phosphate, magnesium oxide and calcium oxide. After polishing the HA ceramics, they were immersed in buffered water at 37°C for 3 and 7 days. The bone ash derived- biphasic calcium phosphate ceramics show high biostability in liquid environment with immersion time compared with commercial calcium phosphate ceramics.


2016 ◽  
Vol 697 ◽  
pp. 547-550 ◽  
Author(s):  
Meng Fei Wu ◽  
Yuan Bing Li ◽  
Shu Jing Li ◽  
Ya Wei Li ◽  
Shao Bai Sang

In this paper, high-purity porous calcium hexaluminate materials were prepared with α-alumina, nano-meter calcium carbonate and ρ-alumina as raw materials. The properties of the prepared porous materials, such as bulk density, true density, thermal conductivity, and cold crushing strength, were investigated. The increase in sintering temperature led to the increase of true density. Bulk density and cold crushing strength of the specimen fired at 1500°C had the lowest values. As ρ-alumina content increased, bulk density, true density, and cold crushing strength had no obvious changes, but the thermal conductivity decreased at first and then increased. The calcium hexaluminate formation was intense from 1450°C to 1500°C and finished at 1500°C. Above 1500°C, the main phase of specimens was calcium hexaluminate (CA6). And CA6 grains were regular hexagonal plates morphology and widely spread after firing at 1550°C.


2015 ◽  
Vol 804 ◽  
pp. 143-146
Author(s):  
Narumon Lertcumfu ◽  
Parkpoom Jarupoom ◽  
Pongthep Arkornsakul ◽  
Tawee Tunkasiri ◽  
Denis Russell Sweatman ◽  
...  

Calcium phosphate is a biomaterial which exhibits excellent biocompatibility, bioactivity and biodegradability for bone replacement and other medical applications. In the present work, multiphasic calcium phosphate compounds consisting of hydroxyapatite (HAp) and tri-calcium phosphates (TCP) were prepared by a solid state reaction method. Effects of calcium carbonate (CaCO3: ±3-5 wt%) on the properties of the studied powders were investigated where calcium carbonate powder was synthesized from a natural product (cockle shell). The phase formation and morphology of the powders were characterization by many techniques such as XRD, SEM and dynamic light scattering techniques. The results showed that amount of calcium carbonate additive affected on the properties of the studied samples.


1984 ◽  
Vol 51 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Lesley C. Chaplin

SummaryCalcium and phosphate concentrations in milk ultrafiltrate prepared at 37 °C over the pH range 4.0–8.0 have been measured and used to calculate the apparent solubility products for various calcium phosphates in milk. Micellar calcium phosphate had a constant Ca/Pi = 1·58·10·03 at all pH values and a near-invariant ion activity product for CaHP04. Apparent solubility products have also been obtained for brushite, hydroxyapatite and amorphous tricalcium phosphate in milk salt solution over a similar pH range. No evidence was found for a hydroxyapatite or amorphous tricalcium phosphate phase in milk.


2016 ◽  
Vol 881 ◽  
pp. 147-152
Author(s):  
Daiara Floriano-Silva ◽  
Nelson Heriberto Almeida Camargo ◽  
Camila Thais Mamani ◽  
Priscila Ferraz Franczak ◽  
Marli Baltazar Roesler Eckstein ◽  
...  

Calcium phosphate bioceramics obtained from raw materials are potential bone substitutes in orthopedic and dental applications. Calcium phosphates attained from calcareous shells using wet methods provide an interconnected microporous framework, shown to be promising and contribute to cell adhesion and proliferation. This study aimed to characterize three different calcium phosphate ratio compositions: (i)1.4, (ii)1.6 and (iii)1.7 molar, sintered for 2 hours at 1100°C and 1200°C. Scanning electron microscopy field effect [FEG] and confocal were used to assess microstructural characterization and Arthur method to determine open porosity. FEG and confocal analyses showed good grain coalescence, sinterability and well defined interfaces for all Ca/P molar at 1100°C and 1200°C. Open porosity and hydrostatic density exhibit better results when using Ca/P molar ratio (iii)1.7 at 1100°C. The results showed that open porosity is related to Ca/P ratio and by temperature. As the Ca/P increases so does the open porosity. Inversely occurs for temperature. As the temperature increases the porosity decreases and in parallel, the grain size increases.


2006 ◽  
Vol 309-311 ◽  
pp. 263-266 ◽  
Author(s):  
Masato Tamai ◽  
Ryusuke Nakaoka ◽  
Toshie Tsuchiya

The cytotoxicity of five calcium phosphate ceramics, hydroxyapatite (HAp), flouroapatite (FAp), α-tricalcium phosphate (α-TCP), β-tricalcium phosphate (β-TCP) and tetracalcium phosphate (TTCP), was investigated. Based on the guidelines of biological test for medical devices in Japan, a cytotoxicity test of these calcium phosphates was carried out using Chinese hamster V79 lung fibroblasts. The cytotoxic study revealed that FAp and α-TCP showed high cytotoxicities. From various analyses, it was considered that the cytotoxicity of the FAp was due to fluorine ions extracted in a culture medium and the cytotoxicity of α-TCP resulted from a decrease in pH of the medium by the phosphoric acid, which produced by hydrolysis of( the α-TCP.


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