Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0205700 (ash)
 15,125 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The characteristics of fly ash from the flue gas desulfurization (FGD) system are important for its reuse and are mainly depend on the desulfurization process. The physical and chemical properties of DSF ash, which refers to fly ash from the dry FGD system for the iron ore sintering process, were investigated. Its mineralogical contents were determined by X-ray diffraction and thermogravimetry analysis, and its micro-morphology was studied by scanning electric micrograph analysis. The results show that DSF ash has a higher CaO and SO3 content, and the main sulfur form is sulfite, with only a part of it oxidized to sulfate. The major minerals present in DSF ash are hannebachite, anhydrite, calcite and portlandite; a minor constituent is calcium chloride. The particles of DSF ash are irregular, fragmentary and small, and hannebachite grows on their surfaces. Particle size is affected by the FGD process, and the ash size from the maximized emission reduction of the sintering-FGD process is lower than that from the circulating fluidized bed-FGD process. The particle size distribution of DSF ash follows the Rosin--Rammler-Bennet equation.
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PMID:Characteristics of fly ash from the dry flue gas desulfurization system for iron ore sintering plants. 2272 Apr 7

Recycling printed circuit board waste (PCBW) waste is a hot issue of environmental protection and resource recycling. Mechanical and thermo-chemical methods are two traditional recycling processes for PCBW. In the present research, a two-step crushing process combined with a coarse-crushing step and a fine-pulverizing step was adopted, and then the crushed products were classified into seven different fractions with a standard sieve. The liberation situation and particle shape in different size fractions were observed. Properties of different size fractions, such as heating value, thermogravimetric, proximate, ultimate and chemical analysis were determined. The Rosin-Rammler model was applied to analyze the particle size distribution of crushed material. The results indicated that complete liberation of metals from the PCBW was achieved at a size less than 0.59 mm, but the nonmetal particle in the smaller-than-0.15 mm fraction is liable to aggregate. Copper was the most prominent metal in PCBW and mainly enriched in the 0.42-0.25 mm particle size. The Rosin-Rammler equation adequately fit particle size distribution data of crushed PCBW with a correlation coefficient of 0.9810. The results of heating value and proximate analysis revealed that the PCBW had a low heating value and high ash content. The combustion and pyrolysis process of PCBW was different and there was an obvious oxidation peak of Cu in combustion runs.
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PMID:Study on characteristics of printed circuit board liberation and its crushed products. 2295 23