Study On The Enrichment Of Germanium In The Fly Ash Of The Chain-conveyer Furnace

There are many ways to extract Germanium from the coal. It is a kind of new technique that Germanium is enriched in the fly ash, which is generated from the coal combustion in the chain stoves. Combined heat and germanium generation system is a new and economic recycling system, which combined central heating and echnology of extracting of germanium. Germanium is enriched in the fly ash in this system. Meanwhile the heat released from coal as it burns is used for central heating. The coal resource in this system has been fully utilized.In this thesis, firstly,the test was carried out on the chain-conveyer furnace of the combined heat and germanium generation system. The components of ash, velocity inside furnace were tested. Coal, ash and slag were sampled. The distribution of particles of ash was measured by Laser Particle Sizer. The ESEM was used to measure the contents and its micro-characteristics. The germanium contents among different sizes of particles of ash were measured.Secondly, the enrichment of the Gemanium in the fly ash was analyzed. The Germanium is enriched in the fly ash and exhaled in the slag. The enrichment factor is highest in the fly ash trpped by the bag filter, which reached 6.72. The germanium contents among different sizes of particles of ash followed unimodal distribution. Most germanium was enriched in fine floccule. By calculating, the diameter, which is less than 10μm, has the highest germanium enrichment rate.Lastly, performance research of wire pipe electrostatic precipitators was simulated by using CFD software. The speeds of distribution, the dust particles trajectory, the particle concentration distribution were also simulated. The collection efficiency of the different size of the fly ash was analyzed. The influence of the collection efficiency by different voltage and the speeds of the import were also analyzed. When the voltage reaches 80 kv and air speed reaches 0.5 m/s, the collection rate of the fly ash, in which the Germanium enrichment rate is highest, nearly reaches 100 percents.In this thesis, mechanism analysis, field test, laboratory analysis and CFD simulation were combined to study on the heat and germanium generation system. The results provide the mechanism basis and data for Germanium enrichment in the fly ash sent out from the chain stoves.