ポーランド産石炭灰の性状について

抄録

Large quantities of coal ash are produced in the world every year by coal-burning powerplants, and have long been a major waste disposal and environmental problem. In accordance with this increase in coal ash, some research programs have been prepared with the goal of utilizing as much of waste as possible.
This waste represents a premined source of several metals. If economic recovery of these metals is realized, the waste has been treated in our country as a important resources.
This research was done in order to provide the fundamental effects of chemical and physical properties of coal ash on a sulfuric acid leaching process. The sample of coal ash from Poland has been mainly examined by means of photomicroscopic observation, electron microprobe analysis, spectro graphic analysis, quantitative analysis, size separation, X-ray diffraction, thermal gravimetric analysis and differential thermal analysis.
The main results obtained are summarized as follows:
The major elemental constituents of coal ash are Si, Al and Fe, together with minor amounts of Ca, Mg, Na, Ti, C and S.
The mineral content of coal ash are primarily mullite (3A1₂O₃·2SiO₂), with the presence of hematite (Fe₂O₃), magnetite (Fe₃O₄) and silica (SiO₂).
The logarithmic probability plots of the screen analysis for sample showed the cumulative weight oversize percent and the cumulative weight undersize percent of each size fraction as a function of the particle diameter. The results should be useful in recovering the metals which are contained in a coal ash in a sulfuric acid leaching process.