[Show abstract][Hide abstract] ABSTRACT: Studied are the ash fusion characteristics obtained from the mixed incineration of 1. three types of coal (Yuanbaoshan-origin lignite, Cuijiagou-origin bituminous coal and Xuzhou bituminous coal, hereinafter referred to as coal Y, coal C and coal X for short respectively), which have different ash fusion characteristics, and 2. chemical waste-liquid red water with different salt contents (the content of alkali metal sodium salt Na2SO4, NaNO3 and Na2CO3 etc. in red water, hereinafter generally referred to as the salt content) . The study results show that if no limestone is added, the ash fusion temperature of coal X and coal C tends to go down as a result of an increase in salt content of the red water, during which under an identical salt content, the ash fusion temperature of coal X drops by a relatively big margin and that of coal Y tends to go down at the beginning and then go up followed by a go-down. After limestone (Ca/S = 2.0) has been added, with an increase in the salt content of the red water, the ash fusion temperature of coal X displays a tendency to first fall and then rise and there exists a minimum value among its four characteristic temperatures when the salt content of the red water is 10%. By contrast, the ash fusion temperatures of coal C and coal Y undergo a change similar to the case when no limestone is added. However, the above change is relatively small. At a certain salt content (15%) and with an increase in added amount of limestone, the ash fusion temperature of coal X and coal C will all first go down and then up, but for coal X there is a significant change. The deformation and softening temperature of coal Y rises while its hemispheric and flow temperature goes down first and then up. The research results provide a theoretical basis for the prevention of coking of bed materials when organic salty waste liquid is fired in a fluidized bed.
[Show abstract][Hide abstract] ABSTRACT: Porous calcium polyphosphate (CPP) scaffolds with different polymerization degree and crystalline phases were prepared, and
then analyzed by scanning electron microscopy (SEM), Thermmogravimetry (TG) and X-ray diffraction (XRD). Number average polymerization
degree was calculated by analyzing the calcining process of raw material Ca(H2PO4)2, as a polycondensation reaction. Amorphous CPP were prepared by the quenching from the melt of Ca(H2PO4)2 after calcining, and CPP with different polymerization degree was prepared by controlling the calcining time. Meanwhile,
CPP with the same polymerization degree was prepared to amorphous or different crystalline phases CPP which was made from
crystallization of amorphous CPP. In vitro degradation studies using 0.1 M of tris-buffered solution were performed to assess the effect of polymerization degree or
crystalline phases on mechanical properties and weight loss of the samples. With the increase of polymerization degree, the
weight loss during the degradation decreased, contrarily the strength of CPP increased. The degradation velocity of amorphous
CPP, α-CPP, β-CPP and γ-CPP with the same polymerization degree decreased in turn at the same period. The full weight loss
period of CPP can be controlled between 17 days and more than 1 year. The results of this study suggest that CPP ceramics
have potential applications for bone tissue engineering.
No preview · Article · Apr 2006 · Journal of Materials Science
[Show abstract][Hide abstract] ABSTRACT: In order to resolve the degradation velocity of scaffolds matching with the growth velocity of cells, the calcium polymphosphate (CPP) with different polymerization degree were prepared by controlling the calcining time. Results showed that with the increase of polymerization degree, the weight loss during the degradation decreased, contrarily the strength of CPP increased. The full weight loss period of amorphous CPP is 17 days and the weight loss of a-CPP is about 5 % during the period of 30 days. Because of its inorganic polymeric structure and the degradability, the controllable degradation of CPP can be possibly achieved.