Author/Authors :
Susan Essien Etok، نويسنده , , Eugenia Valsami-Jones، نويسنده , , Timothy J. Wess، نويسنده , , Jennifer C. Hiller، نويسنده , ,
Clark A. Maxwell، نويسنده , , Keith D. Rogers، نويسنده , , David A. C. Manning، نويسنده , , Margaret L. White، نويسنده , , Elisa Lopez Capel، نويسنده , , Matthew J. Collins، نويسنده , , Mike Buckley، نويسنده , , Kirsty E. H. Penkman، نويسنده , ,
Stephen L. Woodgate، نويسنده ,
Abstract :
The thermal behaviour of the animal by-product
meat and bone meal (MBM) has been investigated in
order to assess how it is affected structurally and chemically
by incineration. Initially composed of intergrown
collagen and hydroxyapatite (HAP), combustion of the
organic component is complete by 650 C, with most mass
loss (50–55%) occurring by 500 C. No original proteins
were detected in samples heated at 400 C or above.
Combustion of collagen is accompanied by an increase in
HAP mean crystallite size at temperatures greater than
400 C, from 10 nm to a constant value of 120 nm at
800 C or more. Newly formed crystalline phases appear
beyond 400 C, and include b-tricalcium phosphate,
NaCaPO4, halite (NaCl) and sylvite (KCl). Crystallite
thickness as judged by small angle X-ray scattering
(SAXS) increases from 2 nm (25–400 C) to 8–9 nm very
rapidly at 550 C, and then gradually increases to
approximately 10 nm. The original texture of HAP within a
collagen matrix is progressively lost, producing a porous
HAP dominated solid at 700 C, and a very low porosity
sintered HAP product at 900 C.
