The main material of electric arc furnace steel makers is scrap steel. The scrap steel was melted and reduced into molten steel and the substance of lower melting and boiling points are concentrated in fly ash. The ash collected by dust collector contains also, other than organic pollutants like polycyclic aromatic hydrocarbons, (PAHs), inorganic heavy metal pollutants, such as zinc, cobalt and lead. It is found that the content of zinc and cobalt in the ash are exceeding statutory standard of 5 mg/L and 1 mg/L. They are hazardous industrial waste.In the Steel Basic Industry Collected Dust Storage Extending Review Operation Key Point as amended on July 1, 2010 by Environmental Protection Administration, all the steel mills shall complete treatment of the stored collected dust before June 30, 2014 and no further storage will be permitted. Due to the fact that domestic capacity of treating collected dust is insufficient to meet the statutory requirements, the final treatment and disposition of collect duct has become a serious question to the steel mills.In this research, we press the dust collected in the process of arc furnace steel making into ingot and place into arc furnace for further melting and refining. Under temperature of 1600 ¢Jpart of the heavy metal is gasified and returned to waste gas and become collected dust and part of Silicon Dioxide and Magnesium Oxide are sintered into slag and turn the hazardous industrial waste into recycled industrial waste for further utilization, so that they may be disposed. After melting treatment, the collected dust, the regenerated dust has the zinc compound content increased to 13.45% and therefore increases the recycling value of collected dust. In this process, Iron Oxide is reduced 9.41% which can be turned into steel billet (product) and Silicon Dioxide and Magnesium Oxide are reduced 2.67% and were turned into slag.Results of this research indicated that after melting treatment of collected dust, it will be reduced 0.26% and is therefore good for waste reduction.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0908110-132955 |
| Date | 08 September 2010 |
| Creators | Sir, Ming-Shiang |
| Contributors | Kuo-Ching Chang, Hua-Shan Tai, Chiu-Jung Liao, Jimmy C. M. Kao |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0908110-132955 |
| Rights | not_available, Copyright information available at source archive |
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