| 摘要 |
<p>PURPOSE:A dephosphorizing agent which is composed of the CaO in which a portion of grain boundaries of the fine CaO primary crystal constituting CaO are filled by amorphous C, as well as amorphous C, and which makes the slagging of CaO faster as compared with ordinary dephosphorizing agents mainly composed of CaO. CONSTITUTION:The calcareous material which is mainly composed of CaCO3 or/and Ca(OH)2 is calcined in a nonoxidative atmosphere with the supply of CO or/and organic compound gas (e.g.: CH4). The gas composition of the calcining zone in this case maintains the content of CO at 2.0 or more and the content of CH4 at 0.7 or more, respectively with respect to the O2 contained based on volume, and the nonoxidative atmosphere is maintained by the supply of the CO and the organic compound gas in excess amount with respect to the O2 contents. As a result of this calcining, the calcareous material is decomposed to CaO and at the same time said calcareous material is decomposed to quicklime, whereby the dephosphorizing agent in which the Ca components contained are deposited as amorphous C at the grain boundaries of the fine CaO primary crystals constituting CaO is obtained. This dephosphorizing agent is composed of 100pts.wt. quicklime and 4-20pts.wt. amorphous carbon and the dephosphorizing time of molten iron may be reduced by using this.</p> |
