阅读说明：本技术 一种用转炉工艺给熔融还原炉提供热装铁水的方法 (Method for providing hot charging molten iron for smelting reduction furnace by converter process ) 是由 张勇 李聿军 徐涛 周海川 卜二军 任俊 程鹏 昝智 于 2021-09-09 设计创作，主要内容包括：本发明公开了一种用转炉工艺给熔融还原炉提供热装铁水的方法,包括以下步骤：在转炉内兑入与转炉公称重量接近的铁水,下氧枪冶炼,在不发生喷溅的前提下枪位控制到最低,确保铁水快速升温,吹炼后将载有烘烤好的铁水罐的运输车开至出铁位置,向铁水罐中加入一定量的硅铁和增碳剂,铁水温度在1650-1700℃之间,加入适量的石灰,提枪出铁,出铁过程中随铁流加入适量硅铁,将铁水含硅量调至成分内控范围,出铁结束后,盖好保温盖,将铁水运输至熔融还原炉装炉或等待装炉,接着冶炼下一罐铁水,直至达到熔融还原炉要求的铁水量后,转炉切换至炼钢模式。该方法能快速高效地冶炼熔融还原炉所需要的热装铁水,具有铁水温降低、成本低,极大地提高了熔融还原炉开炉成功率的优点。(The invention discloses a method for providing hot charging molten iron for a smelting reduction furnace by using a converter process, which comprises the following steps: adding molten iron with the weight close to the nominal weight of the converter into the converter, smelting by an oxygen lance, controlling the lance position to be the lowest on the premise of no splashing, ensuring the rapid temperature rise of the molten iron, driving a transport vehicle carrying the roasted molten iron tank to a tapping position after blowing, adding a certain amount of ferrosilicon and carburant into the molten iron tank, adding a proper amount of lime into the molten iron tank when the temperature of the molten iron is 1650-. The method can rapidly and efficiently smelt the hot charging molten iron required by the smelting reduction furnace, and has the advantages of reducing the temperature of the molten iron, lowering the cost and greatly improving the blow-in success rate of the smelting reduction furnace.)

1. A method of supplying hot charged molten iron to a smelting reduction furnace by a converter process, comprising the steps of: adding molten iron with the weight close to the nominal weight of the converter into the converter, smelting by an oxygen lance, controlling the lance position to be the lowest on the premise of no splashing, ensuring the rapid temperature rise of the molten iron, driving a transport vehicle carrying the roasted molten iron tank to a tapping position after blowing, adding a certain amount of ferrosilicon and carburant into the molten iron tank, adding a proper amount of lime into the molten iron tank when the temperature of the molten iron is 1650-.

2. The method of supplying hot-charged molten iron to a smelting reduction furnace according to claim 1, wherein the oxygen supply strength for the lower lance is 3.5 to 5.0m³And (min.t molten iron), blowing for 3.5-4.5min, and then driving the transport vehicle carrying the baked molten iron tank to a tapping position.

3. The method as claimed in claim 1, wherein the method of supplying hot charged molten iron to the smelting reduction furnace using the converter process comprises adding a predetermined amount of ferrosilicon and a carburant to the molten iron tank, blowing the molten iron for 5 to 7min to a temperature of 1650-1700 ℃, adding a predetermined amount of lime, and extracting the iron using a lance.

4. The method for supplying hot charged molten iron to a smelting reduction furnace according to claim 1, wherein the temperature of the molten iron charged into the converter is not lower than 1250 ℃ and the temperature of the inner wall of the molten iron tank is not lower than 800 ℃.

5. The method as claimed in claim 1, wherein the mass percentages of carbon and silicon in the charged molten iron for the smelting reduction furnace are controlled to be 4.00-5.00% and 2.00-2.50%, respectively, at 1650-1700 ℃.

6. The method of claim 1 for providing hot charged molten iron to a smelting reduction furnace using a converter process, comprising: adding ferrosilicon at the beginning of tapping 1/4, and finishing tapping 2/3.

Technical Field

Embodiments of the present disclosure relate generally to the field of iron and steel smelting, and more particularly, to a method of providing hot charged molten iron to a smelting reduction furnace using a converter process.

Background

Generally, the iron bath smelting reduction technology is to inject iron ore powder and a reducing agent (such as coal powder, hydrogen gas, etc.) into an iron bath furnace, and the iron ore powder and the reducing agent are melted in molten iron to perform a reduction reaction to obtain molten iron. Therefore, a certain amount of external molten iron must be poured into the iron bath furnace when the furnace is opened.

Manufacturers adopting the iron bath smelting reduction technology generally build an intermediate frequency furnace, add scrap steel and alloy into the intermediate frequency furnace before opening the furnace, and melt the scrap steel and the alloy by induction heating to produce required molten iron for a smelting reduction furnace. However, the method has long time and high cost for smelting the molten iron, so that the charging interval or waiting time of the molten iron in the smelting reduction furnace is long, the temperature of the molten iron is quickly reduced, the blowing-in failure is easily caused, and the intermediate frequency furnace is in an idle state for a long time during the non-blowing-in period of the smelting reduction furnace, so that the capital investment is increased.

The technology of smelting molten iron by converter process provides a new method for providing hot charging molten iron for smelting reduction furnace. The method can rapidly and efficiently smelt the hot charging molten iron required by the smelting reduction furnace, has the advantages of reducing the temperature of the molten iron, lowering the cost and greatly improving the furnace opening success rate of the smelting reduction furnace, and can realize seamless switching to steel making without smelting the molten iron, thereby avoiding equipment idling.

Disclosure of Invention

In order to solve the technical problems and achieve the corresponding technical effects, the invention provides a method for providing hot charging molten iron for a smelting reduction furnace by using a converter process.

According to the embodiment of the disclosure, a method for providing hot charging molten iron for a smelting reduction furnace by using a converter process is provided, and the method has the characteristics of short smelting time, small molten iron temperature reduction and low cost.

A method of supplying hot charged molten iron to a smelting reduction furnace using a converter process, comprising the steps of: adding molten iron with the weight close to the nominal weight of the converter into the converter, smelting by an oxygen lance, controlling the lance position to the lowest under the premise of no splashing, ensuring the rapid temperature rise of the molten iron, driving a transport vehicle carrying the roasted molten iron tank to a tapping position after blowing, adding a certain amount of ferrosilicon and carburant into the molten iron tank, adding a proper amount of lime into the molten iron tank when the temperature of the molten iron is 1650-.

Further, the oxygen supply intensity for smelting by the lower oxygen lance is 3.5-5.0m³And (min.t molten iron), blowing for 3.5-4.5min, and then driving the transport vehicle carrying the baked molten iron tank to a tapping position.

Further, adding a certain amount of ferrosilicon and carburant into the hot metal tank, blowing for 5-7min, adding a proper amount of lime into the hot metal tank at the temperature of 1650-1700 ℃, and extracting iron by a lance.

Further, the temperature of the molten iron added into the converter is not lower than 1250 ℃, and the temperature of the inner wall of the molten iron tank is not lower than 800 ℃.

Further, the mass percentages of carbon and silicon in the charging molten iron required by the smelting reduction furnace are respectively controlled to be 4.00-5.00% and 2.00-2.50%, and the temperature is 1650-1700 ℃.

Further, adding ferrosilicon is started when tapping 1/4, and tapping 2/3 is finished.

The invention has the advantages and effects that:

compared with the prior art of providing blow-in molten iron for a smelting reduction furnace, the invention has the following advantages:

high efficiency, high speed and high success rate of blowing in. The time for smelting molten iron is shortened by more than half, the time for waiting for blow-in is short, the temperature of the molten iron is reduced, and the blow-in success rate of the smelting reduction furnace is improved.

The cost is low. The method utilizes the oxidation temperature rise of carbon, silicon and manganese in the molten iron, and has the cost lower than that of the molten iron smelted by using an intermediate frequency furnace to inductively heat and melt scrap steel by more than 200 yuan/(t molten iron).

The investment is saved. The converter adopted by the invention can realize seamless switching of iron making and steel making, and can not cause equipment to be idle.

It should be understood that the statements herein reciting aspects are not intended to limit the critical or essential features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become apparent from the following description.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below, and it is obvious that the described embodiments are some embodiments of the present disclosure, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

A method of supplying hot charged molten iron to a smelting reduction furnace using a converter process, comprising the steps of:

molten iron with the weight close to the nominal weight of the converter is added into the converter, the converter is placed on an oxygen lance for smelting, the lance position is controlled to be the lowest on the premise of no splashing, and the oxygen supply intensity is 3.5-5.0m³And v (min.t molten iron), ensuring the rapid temperature rise of the molten iron. And after blowing for 3.5-4.5min, driving a transport vehicle carrying the baked hot metal ladle to a tapping position, and adding 22-25kg/(t molten iron) ferrosilicon and 10-12kg/(t molten iron) carburant into the hot metal ladle. In the smelting process, the molten iron flame emitted from the converter mouth is observed to judge the molten iron temperature, and the molten iron temperature is within 5-7min after blowing1650-1700 ℃ (if a sublance is provided, the carbon and temperature can be fixed by the sublance), 2-3 kg/(t molten iron) lime is added to form a heat-preservation slag layer on the surface of the molten iron after tapping, and then the sublance is lifted for tapping. Adding a proper amount of ferrosilicon along with the iron flow in the process of tapping, and adjusting the silicon content of the molten iron to the component internal control range. And after tapping, covering a heat-insulating cover, and conveying the molten iron to a smelting reduction furnace for charging or waiting for charging. And smelting the next pot of molten iron until the molten iron amount required by the smelting reduction furnace is reached, and switching the converter to a molten steel smelting mode.

Preferably, the nominal capacity of the converter is not less than the nominal capacity of a hot metal ladle provided in the smelting reduction furnace. If the nominal capacity of the converter is several times of the nominal capacity of the hot metal ladle, the smelted hot metal in one ladle can be loaded into a plurality of hot metal ladles, and the temperature drop of the hot metal is further reduced.

Further, the temperature of the molten iron fed into the furnace is not lower than 1250 ℃.

Further, the temperature of the inner wall of the baked hot-metal ladle is not lower than 800 ℃. Preferably, the temperature of the inner wall of the roasted molten iron tank is 1000-1100 ℃ so as to reduce the tapping temperature drop.

Further, the ferrosilicon addition was started at tapping 1/4 and completed before tapping 2/3.

Further, the ferrosilicon and the carburant adopted by the invention respectively meet the requirements of GB/T2272-. But not limited to, the grade or grade of ferrosilicon or carburant. If ferrosilicon or carburant with other brands or grades is added, the adding amount needs to be adjusted, so that the molten iron components meet the requirements of hot charging molten iron components in the smelting reduction furnace.

Example 1

The mass percentages of carbon and silicon in the charging molten iron required by the melting reduction furnace are respectively controlled to be 4.00-5.00% and 2.00-2.50%, and the temperature is 1650-.

In this example, the nominal capacity of the hot metal tank and the converter provided in the smelting reduction furnace were both 80t, 85t of molten iron was charged into the converter, the mass percentages of carbon and silicon in the charged molten iron were 4.40% and 0.36%, respectively, by assay, and the temperature was 1300 ℃, and the composition of the tapped molten iron was adjusted to the requirements of the smelting reduction furnaceAnd (5) controlling. Blowing with a lower lance, controlling lance position at 841mm, and oxygen supply intensity at 4.05m³And (min.t molten iron), no splashing exists in the whole smelting process.

Blowing for 4min, driving a transport vehicle carrying the baked hot metal ladle to a tapping position, wherein the temperature of the inner wall of the hot metal ladle is 1050 ℃, and adding 24kg/(t molten iron) ferrosilicon and 12kg/(t molten iron) carburant into the hot metal ladle.

Smelting for 5 minutes and 43 seconds, observing that the flame temperature of molten iron exceeds 1650 ℃, adding 2.5kg/(t molten iron) lime, lifting a gun, stopping blowing, reversing the furnace, measuring the temperature, and sampling, wherein the temperature is 1670 ℃, and the carbon content is 3.52%. And (3) immediately tapping when the required temperature is reached, wherein ferrosilicon is added when tapping 1/4 is finished, and the total quantity of the added ferrosilicon is 8.5kg/(t molten iron) when tapping 2/3 is finished.

After the molten iron is discharged, sampling and testing are carried out, and the mass percentages of carbon and silicon are respectively 4.55 percent and 2.36 percent, thereby meeting the requirement of internal control of components. And covering the ladle cover, and conveying the molten iron to a smelting reduction furnace to prepare for opening.

Example 2

In the present example, the given conditions were the same as in example 1 unless otherwise specified.

In this example, 88.5t of molten iron was charged into a converter, and the mass percentages of carbon and silicon in the charged molten iron were 4.52% and 0.46%, respectively, by assay, at a temperature of 1330 ℃. Blowing with a lance, controlling the lance position at 870mm, and supplying oxygen at 3.87m³And (min.t molten iron), the whole smelting process has no splashing.

Blowing for 4.1min, driving a transport vehicle carrying the baked hot metal ladle to a tapping position, controlling the temperature of the inner wall of the hot metal ladle to be 1045 ℃, and adding 23kg/(t molten iron) ferrosilicon and 11kg/(t molten iron) carburant into the hot metal ladle.

Smelting for 5min and 8 sec, observing that the flame temperature of molten iron exceeds 1650 deg.c, adding 2.8 kg/t molten iron lime, stopping blowing, reversing the furnace, measuring temperature and sampling, wherein the temperature is 1675 deg.c and the carbon content is 3.60%. And (3) immediately tapping when the required temperature is reached, wherein ferrosilicon is added when tapping 1/4 is finished, and the total quantity of the added ferrosilicon is 8.1kg/(t molten iron) when tapping 2/3 is finished.

After the molten iron is discharged, sampling and testing are carried out, and the mass percentages of carbon and silicon are respectively 4.48 percent and 2.27 percent, thereby meeting the requirement of internal control of components. And covering the ladle cover, and conveying the molten iron to a smelting reduction furnace to prepare for opening.

The invention adopts the converter process to provide hot charging molten iron for the smelting reduction furnace, and has the advantages of high efficiency, high speed, low cost, high success rate of furnace opening and investment saving.

In the description of the present application, the description of the terms "one embodiment," "some embodiments," etc. means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. Throughout this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.