Posted 28 Dec 2010 23:27
Slag splashing with the unquestionable advantage of new technology, but with every new technology will inevitably have some problems, due to the actual situation of each plant is different in different degrees, nodulation lance, bottom up and phosphorus content of steel increases and other issues. At home and abroad are discussed below in this regard a solution to the problem, the oxygen lance *** nodulation nodulation is converter slag splashing practices, domestic and foreign steel mills are experiencing problems. During the slag splashing Although there before gunning lance nodules, but with this technology, the problem becomes more prominent. As the process of slag splashing slag oxygen lance is covered, if the residual molten steel converter, will exacerbate the extent of nodulation lance. LTV Corporation, Indiana United States to Hong Kong factories to effectively solve this problem. First, the oxygen cooling water *** with adequate oxygen lance to avoid clogging. Second, if the removal of hot water for blowing oxygen steel ***, the replacement of oxygen on a cold ***, installed in the bracket on the slag splashing gunning to basically eliminate the clogging problem. These results indicate that nodulation lance temperature or heat transfer may be related. Can not seem to slag a sniper with an excellent surface bonding. If you fill furnace slag splashing does not exist in the process of molten steel, it will not surface in the rough surface oxygen lance, which the slag can not adhere on it. Gunning, will complement furnace slag splashing guns parked on the stent, the formation of slag cooling and oxygen *** shell will peel, and finally fall off. U.S. Algoma Gangchang the same with the two way exchange of main and sub guns to Penqiang minimizes nodulation. The method is the main *** for blowing oxygen, nitrogen, Deputy *** used to blow, the Deputy *** in position by a steel converter at the top of the operator to determine the normal height of the steel surface oxygen blowing *** on 2m, and nitrogen blow *** the height to 0 ~ 2m, practical results show that the lance in the slag slag splashing liquid surface 1.1m better, the converter trunnion can guarantee a certain amount of slag splashed area. Lance domestic steel mills to solve the problem is the key to nod before the final slag slag splashing as much as possible without leaving any residue within the steel. Second, the bottom up bottom up is the slag splashing process should not be ignored, on the smelting operation is very unfavorable. The bottom up high, the *** position at a higher level control, likely to cause splashing, back to dry, oxygen consumption increased ***. Fill in the furnace slag splashing process, the steel workers must be very careful, bottom not covered with excessive slag. Nitrogen flow to be high, the bottom of the converter slag can disperse through the spray nozzle or mixing components of the gas pressure or flow into the need to change. Indiana Port plant two 252t basic oxygen furnace, the furnace bottom of the ring nozzle used to enhance the melt mixing. The plant in the bottom rises too high, the use of thinning bottom techniques, namely by increasing the nozzle pressure and flow of gas, this new method is based on the location for the center of nozzle holes drilled 152mm, and the high magnesium refractory filling the air around the mouth, mouth to reduce wind erosion, because the nozzle is not surrounded by slag, do not plug the nozzle in the case of the slag has been erosion of the bottom. TISCO two practice shows that the steel slag splashing, blowing slag not only affect the duration of the effect linked to residue quality, also affects the bottom of the situation, the longer blowing slag, lining residue linked to more, but too long will Furnace the end of pool surface dross too much, resulting in bottom up. Slag best time to ensure that 215 ~ 315min. Jiuquan Iron and steel mill bottom according to different states, with different slag splashing process parameters. When the bottom up, the oxygen from the bath surface tips and the case for the 1.5m, lance slag splashing down to 1500mm, nitrogen injection pressure increased to 0.85 ~ 0.90MPa, nitrogen flow up to 9000 ~ 10000Nm3 / h , slag splashing time of 2.5 ~ 3.5min. Third, the molten steel by P according to the theory and practical experience in the process of slag splashing, splashes, and attached to the lining of the slag composition is crucial, mainly MgO and FeO content. FeO content, slag fluidity, slag after slag splashing in the lining of the hanging is not easy. Furnace in order to obtain a better effect of protection, control and adjust the smelting process Slag MgO content of slag before the slag splashing process component is necessary, by adding thickening agent to the slag slag MgO content from 6.5% to 8% or more, A typical use of slag MgO content of 8% to 14%, and this not only reduces the process of smelting slag splashing lining layer of brick or erosion, but also ensures a certain degree of splashing slag MgO content. Therefore, operating on the high MgO slag steel workers is a real challenge, because the slag viscosity, the phosphorus content of steel will bring potential problems. LTV Corporation, Indiana United States the average phosphorus content of hot metal factory in Hong Kong was 0.075%. Take high MgO slag steelmaking process must be balanced with the whole way, for the dephosphorization of steel demanding, while maintaining the premise of high-viscosity slag MgO content in slag to reduce the phosphorus problem solving, the steel for the important , high MgO content of the slag can be used, and the development of the viscosity ratio between the amount of change and added MgO diagram. Inland Steel Company and other manufacturers of the United States's experience, when high phosphorus hot metal after blowing more than twice the heats, you can give up slag splashing operation. Therefore chosen a better way to control the sources of phosphorus may consider taking on the hot metal pretreatment process, the molten iron into the converter is not before the sulfur content will be reduced to low levels of phosphorus.