Jian Hua Zeng

Research on Extending the Lifetime of Combined Blowing Vanadium Recovering Converter

Focus on such problems as low supplying capacity, short furnace life and poor smelting effect during extracting vanadium using combined blowing converter, the structure optimization of bottom blowing brick used to ventilating was studied, the system used to supplying gas was implemented, and the crafts of extracting vanadium with combined blowing technology was developed as well as the protecting technology of brick used to ventilating was applied. The results show that strength of gas supplying of BOF is increased to at least 0.10m3/ (min•t). The combined blowing lifetime is extended, especially reaches to 7455 heats. The proportion of multiple blowing is reached to 100%. The quality o f vanadium slag is improving obviously.

Optimization of Steelmaking Process for 200t Converter

To solve the problems appeared in the initial operation period of 200t BOF such as low heating velocity, high TFe content in final slag, severe lining erosion, etc, optimization of steelmaking process is carried out. Metallurgical effects are greatly improved after optimization: slag-forming time is shortened by 0.9min; oxygen consumption is lowered by 1.5 m3 per ton steel; carbon content of aimed molten iron is increased by 0.031% while oxygen activity of which is decreased by 206ppm. TFe content of BOF slag is reduced by 0.84% on average.

Development and Application of a New Carburant Material

Anthracite carburant is adopted to increase the carbon during the steel tapping of the converter of Panggang, however, it is found that the smelting time is long and the yield rate of the carbon is low which severely affect the precision control of the heat composition, so the new type of carbon-manganese alloy carburant is developed and the application effect to the industry is investigated. The results show that this new type carbon-manganese alloy carburant smelting much faster, and the yield of the carbon and manganese are high, the average yield of carbon is 92.95%, which is 7.36% higher than anthracite, the manganese is 93.31%。This new type carburant for increasing the carbon can decrease the temperature of the tapping in the promise of keeping the quality of liquid steel, shorten the logistic time and reduce the cost of steel per ton.

Development and Application of Control Model for Semi-Steel Steelmaking

According to the actual characteristics of semi-steel steelmaking of PZH steel, a static model for prediction of the oxygen blow amount and consumption of auxiliary material is established, and an end-point prediction model based on carbon content and temperature of sublance is given. This paper introduced the calculating principle and basic structure about above two models detailed. The results show that, the static model has certain accuracy and reliability of these models are illustrated by actual application.The static model might provide immediately the predicting optimum auxiliary material amount and the oxygen blow amount for operator, which direct the operation in time. The end-point prediction model might give real time prediction for the carbon content and temperature on BOF Endpoint, which has high hitting ratio.

Research and Application on Parameter Optimizing of Oxygen Lance Nozzle on Converter for Semi-Steel Making

In order to meet the need of production and promote the smelting efficiency of converter, Pangang Vanadium-extracting&Steel Making Plant optimized oxygen lance nozzle according to the situation of primary 120t converter semi-steel making and have inspected new oxygen lances smelting effect in industrial test. The test shows that the average oxygen blowing intensity raised 0.19m3/t·min with optimized nozzle, shortened oxygen blowing time by 56s,total iron in final slag reduced 0.7%, dephosphorizing rate rose to 82.10% from 79.06%, which developed a good result.

The Analysis of Magnesium Compound Desulfurizer and Compound Desulfurizer in PANGANG

This paper firstly analyzed the desulfurization mechanism of magnesium compound desulfurizer and compound desulfurizer. It is thought that the compound desulfurizer which contains a certain amount of magnesium is better used than the one does not contain. There is also the statistical analysis about these two type desulfurizers in practical Producing. The practical application of contrast verifies the theoretical analysis.The magnesium compound desulfurizer has better performance used in the effect of desulfurization, the consumption of desulfurizer, iron loss, process-time, the loss of hot metal temperature and the lance life than compound desulfurizer.

Practice and Analysis of the Technology of Direct-Tapping

Steelmaking Plant of PZH Steel improves the hitting ratio of independent converter model, by optimizing the terminal controlling model of molten steel, stabilizing the charging load in BOF, accelerating the turnover rapid of ladle, improving the quality of semi-steel into the furnace and optimizing the management of production organization. So the ratio of the direct-tapping is improved and increases to more than 50% now from 25% on average in 2011.

The Application of the High Alumina Composite Slag in Semi-Steelmaking

In order to promote the fusion of lime in semi-steelmaking, fluorite was used in converter steelmaking to improve the melting slag ratio, while fluorite is very harmful. In order to make best use of the metallurgical slag and improve the scorification problems in semi-steelmaking, PANGGANG Research Institute developed a new type high alumina composite slag, and accomplished industrial application which also achieved good results. They found that this new type slag can improve the melting slag ratio greatly and decrease the times of “re-drying” and “slopping” throughout the converter steelmaking, the slag sate can be good controlled, at the same time the content radio of TFe decreased significantly.

Test Study and Application of Corundum Slag in Slag-Forming of BOF

The paper introduced the process of slag-forming by using corundum slag in converter. The results showed that Al2O3 in corundum can reduce converter slag melting point, in advance of slag melting. Using this material, slagging process can be ahead of schedule for 30~40 seconds and the whole process of slag melting is good, without splashing, getting drying and lance-sticking. The consumption of metallic material and lime is reduced, and it shortens the melting period.

Research on Low-Phosphorus Steel Melting by Semi-Steel

In this study, double-slag method is used to melt low-phosphorous steel by semi-steel. The results show that, the average phosphorous content of the aimed molten iron of BOF is 0.0052% and after the first slag pure-out, the dephosphorization rate is 56.2%, while the total dephosphorization rate of BOF melting is 92.46%, rang from 91% to 93.4%. Low phosphorous content alloy and slag-stopping tapping technology is adopted and rephosphorization of molten iron is controlled in 0.002%. Finally the average phosphorous of the finished product is 0.0064%, range form 0.0055% to 0.0071%, which means that Pangang Group can produce the steel with phosphorous content is less than 0.008%.