KR20010047206A - A Method For Refining Using High Si Contained Hot Metal - Google Patents

Abstract

PURPOSE: A converter refining method using high silicon hot metal is provided which not only prevents slopping but also improves dephosphorization efficiency. CONSTITUTION: The converter refining method using high silicon hot metal comprises the processes of tilting a furnace body after injecting 10 to 15 kg of hard-burned dolomite for 1 ton of total charging amount into a converter in which 15 to 25% of the total slag remains from the previous operation; injecting an appropriate amount of subsidiary raw material at the appropriate injection time after injecting 10 to 15 kg of calcium oxide for protecting the furnace body into the converter; and converter refining by blowing an appropriate flow rate of oxygen at a proper lance height, wherein the high silicon hot metal comprises 0.50 to 0.85 wt.% of Si, 0.25 to 0.45 wt.% of Mn, and 0.08 to 0.13 wt.% of P.

Description

A Method For Refining Using High Si Contained Hot Metal}

The present invention relates to a converter refining method using molten iron, and more particularly to a converter refining method using high silicon molten iron.

In the converter industry, hot metal and scrap are charged into the converter, and oxygen is blown through the lance to make quicklime (the main ingredient is calcium oxide (CaO)), and minor dolomite (the main ingredients are calcium oxide and oxide). Magnesium (CaO, MgO)), sintered ore (main component is iron oxide), fluorite (main component is calcium fluoride (CaF ₂ )), and so on, impurity elements in the molten iron are carbon (C), silicon (Si), manganese ( A series of operations for removing Mn), phosphorus (P), sulfur (S), titanium (Ti) and the like by oxidative refining are collectively referred to.

The converter refining using the high silicon molten iron is performed in the order of (preparation stage) → (charging) → (sucking work) → (swing) → (exclusion work) as shown in Figure 1, the drilling work is as follows: There is this.

That is, in the first stage, since the silicon content of molten iron in molten iron is high in the early stage of blowing, the amount of silicon oxide (SiO ₂ ) oxidized by pine acid is higher than when using molten iron. Relatively, the concentration of manganese oxide or iron oxide in slag decreases. Due to this, the melting point of the slag increases and the fluidity deteriorates, so the quicklime is inadequate for the goods, and the carbon monoxide produced by the decarburization reaction and the double-slag slag overflow into the furnace due to the poor mixing of the slag at 30 o'clock. .

In addition, in the second and third stages, an excessive atmosphere of slag generated at the beginning and the end of the blow-up period during the addition of subsidiary materials and coolant is added to create an atmosphere in which the generated gas does not flow out smoothly. It is more likely to lead to large slopes. At this time, the slough is ejected out of the furnace because a large amount of slag is ejected out of the furnace, and the phosphorus at the end point is not high because the delinquency of the slag is not properly induced due to the lack of slag in the converter. Since the iron oxide (FeO) is reduced in the slag to a high melting point, the goods are more poor, which makes it difficult to induce a stable Tallin reaction.

An object of the present invention is to provide a converter refining method using a high silicon molten iron which can not only prevent the occurrence of the slope in the converter refining method using the high silicon molten iron, but also improve the delineation efficiency.

1 is a schematic diagram schematically showing a conventional converter operation process

2 is a graph showing an example of blowing patterns and secondary raw material input conditions of the invention and comparative examples

3 is a graph showing iron oxide, manganese oxide content and basicity in slag according to the blowing time of Inventive Example (1) and Comparative Example (1)

4 is a graph showing the phosphorus content in molten iron according to the blowing time of the invention example (1) and Comparative Example (1)

5 is a graph showing the correlation between the carbon content and the phosphorus content in molten steel when operating in the method of the invention and comparative examples

Figure 6 is a graph showing the occurrence rate of phosphorus component when blown by the method of the invention examples and comparative examples

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated.

The present invention is a converter refining method using high silicon molten iron,

Refining 10 to 15 kg of light and small dolomite for 1 ton of total charge into the converter that left 15 to 25 of the total slag in operation last time, stirring the furnace body two or three times, and then injecting 10 to 15 kg of the quick-protecting limestone Preparatory conditions;

Immediately after the start of the sintering, the sintered ore is fed 5-10 kg per 1 ton of full charge, and quicklime is 10 kg or less. 3 ~ 6 times, light dolomite is divided into 2 ~ 4 kg 2 ~ 4 times in one time, and sintered ore is evenly interlocked for temperature correction within the range that heat mixing is allowed. Subsidiary loading conditions of at least 2 to 3 kg of, quicklime and light calcined dolomite with respect to 1 ton of full charge; And

The lance height is 1600-2000mm until the 5th blow, the shed flow rate is 17000-19000Nm3, the lance height is 1600-2000mm, the blow rate is 15000-17000Nm3, and the blown water 15 ~ Up to 25, the lance height is 1600-2000mm, the supply flow rate is 16000-18000Nm3, the blow up height is 25 to 35, the lance height is 1700-2100mm, the feed rate is 15500-17500Nm3, and the blow up to 35 ~ 60 The lance height is 1450-1850mm, the supply flow rate is 16000-18000Nm3, the lance height is 1400-1800mm for the blown up to 60 ~ 75, the feed rate is 14500-16500Nm3, and the feed rate is up to 75 ~ 80 It is 14500-16500Nm3, the lance height is 1450-1850mm, the lance height is 1450-1850mm for the squirting 80 ~ 85, the sending flow rate is 16000-19000Nm3, and the lance height from the 85th to the end of the scooping. Is 1450-1850mm and blow water flow rate is 17500-19500N㎥ And that is characterized by high silicon refining molten iron to turn on the converter refining method using silicon charter.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present inventors recognize that the most important thing for stably removing phosphorus in molten iron and suppressing the occurrence of sloughing is to effectively manufacture slag throughout the whole process of the blowing, and conducts research and experiment on it, and based on the result, In the present invention, when the converter refining using the high silicon molten iron, it is characterized in that the use of the pre-charge residual slag, secondary raw material input method and the blowing pattern in the preparation step.

The high silicon molten iron which can be preferably applied to the present invention includes a high silicon molten iron having a content of silicon in the molten iron of 0.50 to 0.85 weight, a manganese content of 0.25 to 0.45 weight, and a phosphorus content of 0.08 to 0.13 weight.

First, the full charge residual slag utilization method in this invention is demonstrated.

In the present invention, 10 to 15 kg of light and small dolomite is added to 1 ton of total charge in the converter left 15 to 25 of the total slag operated in the refining step of preparing the converter. Inject quicklime. In the conventional operation, the slag left in the last operation was left in the range of 30 to 40, but in the present invention, the amount of residual slag is reduced from the conventional method due to excessive generation of initial blowdown (SiO ₂ ). However, if the slag amount is excessively reduced to leave less than 15 slag, the product of the initial slag is unstable, and if it exceeds 25, the amount of slag in the furnace is increased during the drilling, thereby increasing the probability of the slope.

Therefore, in this invention, it is preferable to set the residual amount of converter slag performed last time to 15-25.

When the amount of the light dolomite is less than 10 kg with respect to 1 ton of total charge, the effect of slag coating is small and the amount of (MgO) in the slag decreases, so that the melting loss with the furnace body lead is increased. In addition, when the content exceeds 15 kg with respect to 1 ton of total charge, the slag hardens too fast and the slag coating property deteriorates, and the viscosity of the initial blown slag increases, which is disadvantageous for the delineation reaction.

Therefore, the amount of light dolomite is preferably set to 10-15 kg with respect to 1 ton of charged amount.

After the light dolomite is added, the furnace body is repeatedly stirred two to three times, which is properly mixed with the light dolomite into which the slag is added, and is attached to the furnace wall.

When the quicklime is less than 10 kg for 1 ton of full charge, the scrap metal strikes the furnace when it is loaded, and there is concern about mechanical damage with the old smoke, and if it exceeds 15 kg for 1 ton of full charge, it causes a problem of initial inferior goods. Let's do it.

Therefore, the input amount of quicklime is preferably set to 10-15 kg with respect to 1 ton of the total charge amount.

Hereinafter, in the present invention, a method of adding subsidiary materials, that is, the amount and timing of adding the subsidiary materials will be described.

In the present invention, by changing the input amount and the timing of the input of the feedstock stably induce slag to further promote the Tallinn reaction.

That is, in this invention, 5-10 kg of sintered ores and 10 kg or less of quicklime are input with respect to 1 ton of full charges immediately after starting a blow.

At this time, if less than 5 kg of sintered ore is added, the amount to be injected into the blower may be increased, and slitting may occur in the blower (60 to 70). Ping may occur. At this time, when the added quicklime exceeds 10 kg, the splitting amount during the blowing period (blowing 30 to 80) cannot be adjusted, which causes the slope due to the instability of the slag.

In addition, in the blowing time of 35 to 70, for each ton of quick charge, quicklime is divided into 2 to 3 kg 2 to 3 kg each time and 2 to 3 kg is injected 2 to 4 times each time for the light dolomite. The sintered ore shall be interlocked evenly for temperature correction within the range in which heat mixing is allowed.

Injecting quicklime and light dolomite as described above supplements the basicity of slag and cools the slag to suppress the reduction of (MnO), (FeO) in the slag. Here, when the divided dose of quicklime and light dolomite exceeds 300 kg, there is a high possibility that the partial supercooling of the slag causes inhomogeneity of the slag, which may cause destabilization of the Tallinn reaction.

At 80 to 85 hours, at least one kind of sintered ore, quicklime and light dolomite is added in an amount of 2 to 3 kg per 1 ton of charge.

Particularly, when the amount of light dolomite is too high, the content of (MgO) in the slag becomes high and the partial supercooling of the slag causes the inhomogeneity of the slag, which causes instability of the delineation reaction. Do not

As described above, in the method of adding subsidiary materials of the present invention, at about 30 times before the blowing, sintered ore is added in order to supplement the basicity with respect to the basicity of (SiO ₂ ) generated in the initial stage of the blowing in order to supplement the basicity, and to promote the recycling of the added lime. An appropriate amount is added to increase (FeO) in the slag lowered.

At the time around 65, the sintered ore injected from the middle of the drilling continuously manages (FeO) in the slag, while the small dolomite is injected into the slag to cool the slag, thereby reducing the (P ₂ O ₅ ) in the slag. To prevent the increase of the phosphorus content (welding phenomenon).

However, since the total input amount of quicklime in the present invention improves the ash content of the quicklime even though it is used less than the conventional method, it is possible to produce molten steel having a low phosphorus content at the end point. Same as

In other words, the dephosphorization reaction in the converter reacts with calcium oxide (CaO), silicon oxide (SiO ₂ ), alumina (Al ₂ O ₃ ), iron oxide (Fe ₂ O ₃ ), and the like, and the calcium silicate (2CaO · SiO ₂ ) , Complex oxides composed of two or more kinds of oxides such as monocalcium silicate (CaO · SiO ₂ ), calcium aluminate (CaO · Al ₂ O ₃ ), calcium ferrite (CaO · Fe ₂ O ₃ or CaO · FeO) The remaining surplus (CaO) contributes to delineation and becomes (4CaO.P ₂ O ₅ ). Therefore, more of the reclaimed (CaO) is beneficial to Tallinn. However, by varying the slag properties at around 30 and 65 before the drilling, the carbon monoxide generated during the drilling is smoothly discharged, thereby preventing the slag from rising up with the exhaust gas and stabilizing the phosphorus component of the molten steel layer. Let's do it.

Hereinafter, the blowing pattern in the present invention will be described.

The blowing pattern can be appropriately controlled by the lance height and the delivery flow rate.

In order to prevent slipping, it is preferable to combine hard and soft blowing at the same time to reduce the lance height and reduce the flow rate to narrow the reaction area of the oxygen jet. Only in this way can the promotion of the secondary materials during the drilling and the stable control of phosphorus in the molten iron can be induced. However, continuous hard blowing can cause slopes due to instability of slag properties. Therefore, during the drilling, it is necessary to adjust the appropriate blowing pattern according to the molten iron characteristics.

In the present invention, soft blowing and hard blowing are controlled in an appropriate manner to facilitate the discharge of the generated gas by lowering the lance height and to reduce the amount of gas generated by reducing the amount of oxygen, while actively using soft blowing to favor Tallinn. .

That is, in the blow pattern in the present invention, the lance height is 1600-2000 mm until the time of blowing 5, the delivery flow rate is 17000-19000 Nm3, the lance height is 1600-2000 mm until the blow 5-15, 15000-17000Nm3, the lance height is 1600-2000mm for the blown up to 15 ~ 25mm, the feeding flow rate is 16000-18000Nm3, the lance height is 1700-2100mm for the blown up 25 ~ 35, and the feedwater flow rate is 15500- It is set to 17500Nm3, the lance height is 1450-1850mm for the smelting 35 ~ 60, the feeding flow rate is 16000-18000N㎥, the lance height is 1400-1800mm for the filtration 60 ~ 75, and the feeding rate is 14500-16500N㎥ In the case of blown up to 75 ~ 80, the supply flow rate is 14500-16500Nm3, the lance height is 1450-1850mm, and in the blown up 80 ~ 85, the lance height is 1450-1850mm, and the songsan flow rate is 16000-19000N㎥. And the lance height is 1450-1850mm from the time of drilling 85 to the end of drilling. It is blown to the flow rate pattern in 17500-19500N㎥.

As described above, by controlling the blowing pattern according to the present invention, it is possible to induce the promotion of the raw materials and the stable control of phosphorus in molten iron during the drilling, and also to prevent the occurrence of the slope due to the instability of the slag properties.

More preferred blowing patterns for the transmission flow rate and lance height control for each blowing time of the present invention are as follows.

In the converter refining method by the subsidiary raw material input method, up to 5 o'clock when the transfer is started to induce ignition gradually, the lance height is 100mm lower than the basic blow pattern to facilitate the ignition, 1800mm, the flow rate is 1st step to lower 500Nm3 to 18000Nm3: Silicon is oxidized until 5 ~ 15, and the flow rate is lowered while leaving the lance height in the first step, the lance height is 1800mm and the acidic flow rate is 16000Nm3. The second step of inducing: 15 to 25 is the period when the oxidation of silicon is finished and decarburization begins, the lance height is 1800mm, the flow rate is 17000N㎥ to induce stronger agitation force than the second step Stage 3: Up to 25 ~ 35 stages, the lance height is lowered to 1700mm and the delivery flow is lowered to 16500Nm3 to induce a weaker agitation force than the first stage. 4th stage of inducing reaction force: Blowing 35 ~ 60 with decarburizing optimiser may cause phenomena such as chlorine, fugitive manganese and sloughing due to additional input of subsidiary materials and coolant. The fifth step inducing a weaker agitation force than the fourth step while lowering the firing point area of the Songsan jet by lowering it to m3: Delamination reaction at the time of (60-75) blowing (MnO) and (FeO) to form the lowest point In order to promote a weaker agitation force than the fifth step to promote the lance height is 1600mm, the delivery flow rate is 15500Nm3. Leaving the acid flow rate, the lance height rises to 1650 mm to induce a weak stirring force to easily induce the production of (MnO), (FeO) in the slag 7: the slag (MnO), ( Fe In order to induce stronger agitation in order to promote Tallinn as O) begins to rise again, the seventh stage and the lance height are left as it is, and the acid flow rate is 17000 Nm3, and the eighth stage stably induces the Tallinn reaction. Lastly, from the 85th to the end of the blow, leave the 8th step and the lance height to induce stronger agitation force to raise the temperature at the end of the blow. And a blowing pattern composed of a ninth step of inducing a strong stirring force for the purpose of suppressing excessive generation and lowering the end point oxygen.

In the blowing pattern, the light dolomite is added 2 to 4 times in an appropriate amount between the fifth and eighth stages to protect the furnace body, and the remainder of the quicklime is preferably divided into three to six times.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

In the 100-ton converter, 1300-1900 kg of light and small dolomite was put into the converter left by 15-25 (about 2 tons to the neck side) of the slag and the 1000-1500 kg of quicklime was added again. do.

After the light dolomite is added, the furnace body is repeatedly tilted two to three times, and then a small amount of scrap iron is added. Then, a high silicon molten iron (carbon: 4.5) having the composition shown in Table 1 is charged, and pure oxygen is blown through the lance. Blowing started.

Blowing pattern and the subsidiary feed conditions applied in this embodiment was as shown in FIG.

Component analysis values for the various sub-materials used in this Example were as Table 2 below.

(Unit: weight) silicon manganese sign brimstone titanium 0.55-0.65 0.25-0.35 0.080-0.12 0.005-0.030 0.050 to 0.080

(Unit: weight) division Calcium oxide Magnesium oxide iron content Manganese oxide Silicon oxide quicklime 92.50 2.20 0.39 - 0.92 Dolomite 56.16 38.80 0.60 - 1.40 Sintered ore 8.42 1.24 48.294 0.42 4.54 division Aluminum oxide Titanium oxide Calcium fluoride carbon brimstone quicklime 0.30 - - - - Dolomite 0.51 - - - - Sintered ore 1.56 0.17 - 2.60 0.034

The molten iron sample collected at the time of blowing at the time of blowing and the completion of the blow (end point) in the converter blow job under the conditions as described above were analyzed, and the results are shown in Table 3 below.

In addition, the average composition of the slag at the blowing point was analyzed, and the results are shown in Table 4 below.

Then, the behavior of iron oxide content (a) and manganese oxide (b) and basicity (c) in typical slag according to the blowing time were investigated, and the results are shown in FIG. 3, and the behavior of phosphorus content in molten iron was investigated. The results are shown in FIG. 4, wherein the molten iron sample was collected according to the blowing time during the blowing operation using a sub lance.

Inventive Example (1) of the following Table 3 was blown according to the subsidiary material input conditions and the blowing pattern of the invention example of FIG.

division number Molten steel component (weight) Blowing 85 End of training (end) carbon manganese sign carbon manganese sign Inventive Example 1 One 0.36 0.15 0.016 0.09 0.12 0.014 2 0.45 0.13 0.018 0.06 0.11 0.015 3 0.35 0.16 0.018 0.06 0.13 0.012 4 0.43 0.15 0.019 0.07 0.12 0.013 Comparative Example 1 One 0.40 0.21 0.029 0.06 0.19 0.019 2 0.37 0.20 0.031 0.05 0.17 0.024 3 0.42 0.25 0.035 0.06 0.18 0.021 4 0.39 0.23 0.033 0.04 0.17 0.022

(Unit: weight) Calcium oxide Silicon oxide Magnesium oxide Iron oxide Manganese oxide Phosphorus Titanium oxide Aluminum oxide Comparative Example 1 40.35 15.23 7.25 27.35 4.21 1.88 1.47 2.26 Inventive Example 1 42.65 14.78 9.28 23.11 4.35 2.13 1.35 2.35

As can be seen in Table 3, the comparative example (1) corresponds to the conventional method, 0.37-0.42 weight of carbon, 0.20-0.25 weight of manganese, and 0.029- of phosphorus content at the time of blowing 85-90. In the case of Inventive Example (1), the carbon content is 0.35 to 0.45 weight, the manganese content is 0.13 to 0.15 weight, and the phosphorus content is 0.016 to 0.019 weight.

At the time of completion of blowing, in the case of Comparative Example (1), the carbon content was 0.04 to 0.06 weight, the manganese content was 0.17 to 0.19 weight, the phosphorus content was 0.019 to 0.024 weight, and the invention content (1) was 0.04 ~ 0.06 weight, manganese content is 0.11 ~ 0.13 weight, phosphorus content is 0.012 ~ 0.015 weight, it can be seen that the action of the phosphorus component in the work in the invention Example (1) was induced.

On the other hand, as shown in Table 4, in the case of Inventive Example (1) it can be seen that the basicity of the slag, magnesium oxide, manganese oxide and phosphate is higher than in Comparative Example (1). This demonstrates that the correlations are well matched with those of molten steel in Table 3, and this also optimizes the method of adding raw materials and the blowing pattern, leading to high slag ash rate during the drilling, and low end manganese and phosphorus contents. Proves that On the other hand, iron oxide was lower in the case of Inventive Example (1) than in Comparative Example (1). This has the effect of improving the molten steel yield and reducing the amount of waste slag generated.

In addition, as shown in Figure 3 and Figure 4, in the case of the invention (1) it can be seen that the basicity in the slag is high, the phosphorus content in the molten iron is kept low throughout the whole process of blowing.

In addition, the iron oxide and manganese oxide in the slag, which is a measure of double phosphorus during the blow, is confirmed to be particularly maintained in the middle of the blow, thereby providing a stable delineation induction with the de-manganese effect.

(Example 2)

In the present embodiment, converter refining was performed in the same manner as in Example 1, except that the difference was that the content of silicon in the molten iron was high, and the composition thereof is shown in Table 5 below.

The molten steel component and the amount of secondary raw materials used during the blowing and the degree of slope occurrence were investigated. The results are shown in Table 6 below.

In addition, the average composition of the slag at the blowing end point was analyzed, and the results are shown in Table 7 below.

Inventive Example (2) in the following Table 6 was blown according to the subsidiary material input conditions and blowing patterns of the invention example of Figure 2, Comparative Example (2) is to be blown according to the subsidiary raw material input conditions and the blowing pattern of the Comparative Example of FIG. .

(Unit: weight) silicon manganese sign brimstone titanium 0.65-0.85 0.30-0.45 0.085-0.130 0.005-0.020 0.06-0.085

division number Subsidiary input Molten steel component (weight) End of training (end) Slope occurrence quicklime Sintered ore Dolomite carbon manganese sign Comparative Example 2 One 3500 2600 1900 0.04 0.12 0.016 medium 2 4100 1900 1900 0.06 0.15 0.017 small 3 3300 2300 1500 0.08 0.16 0.015 medium 4 3600 2600 1700 0.06 0.15 0.018 versus 5 4000 1800 1900 0.06 0.13 0.020 versus Inventive Example 2 One 3100 2200 1900 0.09 0.09 0.010 none 2 3000 2800 1700 0.07 0.11 0.012 small 3 2800 1900 2100 0.06 0.09 0.010 none 4 3300 1800 1700 0.11 0.10 0.013 none 5 3200 2300 1900 0.06 0.09 0.012 none

(Unit: weight) Calcium oxide Silicon oxide Magnesium oxide Iron oxide Manganese oxide Phosphorus Titanium oxide Aluminum oxide Comparative Example 2 38.45 16.95 6.78 27.69 3.78 1.74 1.56 3.05 Inventive Example 2 41.15 15.85 8.89 23.60 3.95 2.05 1.52 2.98

As shown in Table 6, in the case of Comparative Example (2) there is a lot of slope, it can be seen that the manganese at the end point is 0.12 ~ 0.16 weight, phosphorus component is 0.016 ~ 0.020 weight is high.

On the other hand, inventive example (2) it can be seen that there is almost no occurrence of the slope while the manganese at the end point is 0.09 ~ 0.11 weight, the phosphorus component is maintained stably low as 0.010 ~ 0.013 weight.

Therefore, the present invention reflects the good workability while at the same time obtaining a stable phosphorus component in the pretreatment process.

In addition, it was confirmed that while reducing the amount of quicklime, it was possible to produce molten steel having a lower phosphorus content than the end point by improving the ash rate of quicklime.

In addition, as shown in Table 7, Inventive Example (2) was found to have a higher slag basicity, magnesium oxide, manganese oxide, and phosphate than Comparative Example (2), which is the molten steel component of Table 6 above. Compared with the results, the correlation is well matched, and it also proves that the slag goods ratio is high and the manganese and phosphorus contents are lowered during the drilling by optimizing the input method and the blowing pattern.

On the other hand, the iron oxide content is lower in the case of Inventive Example (2) than in Comparative Example (2).

Comparing the slag composition of Table 7 and Table 4, it can be seen that the case of Example 2 is somewhat lower than Example 1 in the basicity and the concentration of phosphate. This is because the content of silicon in the molten iron used in Example 2 is higher than that of Example 1, and because of this, there is a risk of the occurrence of slipping, and the quicklime and light dolomite are slightly increased to adjust for basicity correction and body protection.

On the other hand, the density | concentration of a phosphorus compound is 2.05 weight of invention example (2), while the comparative example (2) is 1.74 weight, and the case of invention example (2) is high. This shows the same high tendency as in Example 1.

In general, a large amount of slag generated during converter refining is advantageous to Tallinn, but it is easy to generate slaping, so the slag basicity is operated somewhat lower. However, slag with low basicity has low melting point and specific gravity and is light, so it is easy to generate slope during drilling. As a result, oxides formed by oxidizing impurity elements in molten iron have a low concentration in slag.

In particular, in the case of the operation in which the slope is large, as shown in Tables 4 and 6, the content of phosphorus in the molten steel at the end as well as during the drilling is high. This is due to the fact that the slapping occurs and the slag is ejected to the outside, so that the amount of slag during the drilling is not enough to contribute to the Tallinn reaction, and the quicklime added after the sling is not able to go to the ashes to contribute to Tallinn and Demanganese.

The stable operation without the occurrence of the slope as in the present invention is possible by applying a pattern appropriate to the derivation at the same time with the derivation of the appropriate sub-material input method during the drilling from the preparation stage.

(Example 3)

According to Examples 1 and 2, about 300 charges were charged, and the correlation between the carbon content and the phosphorus content in molten steel and the phosphorus separation rate were investigated at the blowing time of 85 to 90. 6 is shown.

As shown in FIG. 5 and FIG. 6, it can be seen that the invention example conforming to the present invention enables stable control of P regardless of the carbon content as compared to the comparative example outside the scope of the present invention.

As described above, the present invention optimizes the residual slag that was pre-operated in the preparation step, and derives the auxiliary raw material method and the blowing pattern during the drilling to maintain the proper oxygen potential and the quicklime of the molten iron and slag, and the ash rate of the light dolomite As a result, the phosphorus can be stably induced compared to the conventional method, thereby optimizing slag basicity and iron oxide concentration. As a result, the phosphorus content is less than 0.02 wt. As it can be manufactured, there is a drastic reduction in the component separation rate, thereby reducing the quality of molten steel, reducing the incidence of slopes, reducing raw materials, and increasing the yield of molten steel and significantly reducing the amount of converter slag.

Moreover, in the converter operation using high silicon molten iron, the slopes are inherently inclined to cause environmental pollution inside and outside the factory. The application of the present invention greatly reduces the generation of visible dust as well as the environmental pollution in the factory. There is also.

Claims (2)

In the converter refining method using high silicon molten iron, Refining 10 to 15 kg of light and small dolomite for 1 ton of total charge into the converter that left 15 to 25 of the total slag in operation last time, stirring the furnace body two or three times, and then injecting 10 to 15 kg of the quick-protecting limestone Preparatory conditions; Immediately after the start of the sintering, the sintered ore is fed 5-10 kg per 1 ton of full charge, and quicklime is 10 kg or less. 3 ~ 6 times, light dolomite is divided into 2 ~ 4 kg 2 ~ 4 times in one time, and sintered ore is evenly interlocked for temperature correction within the range that heat mixing is allowed. Subsidiary loading conditions of at least 2 to 3 kg of, quicklime and light calcined dolomite with respect to 1 ton of full charge; And The lance height is 1600-2000mm until the 5th blow, the shed flow rate is 17000-19000Nm3, the lance height is 1600-2000mm, the blow rate is 15000-17000Nm3, and the blown water 15 ~ Up to 25, the lance height is 1600-2000mm, the supply flow rate is 16000-18000Nm3, the blow up height is 25 to 35, the lance height is 1700-2100mm, the feed rate is 15500-17500Nm3, and the blow up to 35 ~ 60 The lance height is 1450-1850mm, the supply flow rate is 16000-18000Nm3, the lance height is 1400-1800mm for the blown up to 60 ~ 75, the feed rate is 14500-16500Nm3, and the feed rate is up to 75 ~ 80 It is 14500-16500Nm3, the lance height is 1450-1850mm, the lance height is 1450-1850mm for the squirting 80 ~ 85, the sending flow rate is 16000-19000Nm3, and the lance height from the 85th to the end of the scooping. Is 1450-1850mm and blow water flow rate is 17500-19500N㎥ Converter refining method and characterized by refining the molten iron and silicon used to turn silicon charter The method of claim 1, wherein the high silicon molten iron is silicon converter in the molten iron content of 0.50 ~ 0.85 weight, manganese content of 0.25 ~ 0.45 weight, phosphorus content of 0.08 ~ 0.13 weight converter .