| Summary: | 碩士 === 國立成功大學 === 資源工程學系碩博士班 === 95 === Abstract:
The research studies the shells of Taiwan shellfishes, such as, oyster, clam, freshwater clam and abalone, as the raw material for preparation of pearl powder.
Firstly, we treat the shells by an intensive mechanical washing by flowing water. A chemical treatment in an ultrasonic reactor of the washed shells was intended for the complete removal of shell converings, using such reagents as (A) NaOCl (sodium hypochlorite), (B) H2O2, (C) HCl. After the clean shells were crushed and grinded, the finished products compared with pearl powder, such as: crystalline phase, content of calcium carbonate, trace element, protein and amino acid.
In the research, the condition of clam conforms to pearl powder mostly among these disused shells. The powder of clam is composed of aragonite by XRD. Its calcium content reaches 46.22% by EDS, its calcium carbonate content reaches 94.06% by TG and its trace element content is close with the commercial pearl powder. In addition, its soluble protein concentration is inferior to concentration of the pearl powder, however, it contains the same category of amino acid as pearl powder and just has the different content.
By way of grinding, we finds that particle size of the clam sample is approximately 28400mesh (D50=0.523μm) after ball-milling for 16h and 14400mesh (D50=1.028μm) after agitation milling for 2h. Results of both methods can achieve the standard that the commercial requests.
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