TWI523952B - The preparation method of modified converter slag - Google Patents

Description

Method for preparing modified converter stone residue

The invention relates to a preparation method of converter stone slag, in particular to a preparation method of modified converter stone slag.

Hearthstone is a by-product of steelmaking. Generally, it can be divided into two types: blast furnace stone and converter stone. Blast furnace stone powder has been widely used in cement concrete, but the converter stone slag contains a large amount of active oxides (such as calcium oxide), which easily reacts with water, which causes the volume expansion of converter slag to change, so in the past, converter stone Slag is considered as solid waste in steel making.

However, in the above modification method, since the content of FeO in the converter slag is limited, a large amount of heat source cannot be supplied to raise the temperature to maintain the converter slag in a liquid slag state, and a cooling effect is also generated when the blasting sand is blown, so When the product is upgraded, the converter stone slag is easy to be solidified due to cooling, and the reforming success rate of the converter stone slag is reduced, so that the converter stone slag can no longer be used, causing a large amount of waste to be generated and polluting the environment.

In view of the shortcomings of the conventional method for upgrading the converter stone slag, which is easy to be cooled and solidified due to insufficient heat source, and the reform cannot be continued, the inventor of the present invention first considers adding the material containing aluminum metal to the converter stone slag before blowing oxygen. Producing oxygen by reacting aluminum metal in a material containing aluminum metal with oxygen blown in The heat energy released during the aluminum is used as a heat source to raise the temperature of the converter stone slag during the upgrading process, so that the converter stone slag can be maintained in the liquid slag state for a long time, so as to compensate for the problem of insufficient heat source in the conventional method.

Therefore, the object of the present invention is to provide a method for preparing a modified converter stone slag which is not easily cooled and solidified due to insufficient heat source during the upgrading process.

Therefore, the method for preparing the modified converter stone slag of the present invention comprises the following steps: (1) adding a material containing aluminum metal to the liquid converter stone slag to obtain an aluminum-containing converter stone slag; and (2) forming the aluminum-containing converter stone slag After the oxygen is blown into the middle, the temperature is raised to obtain a temperature-returning stone slag; and (3) the blasted sand is blown into the temperature-controlled converter stone slag to be modified to obtain a modified converter stone slag.

The effect of the invention is that in the process of upgrading the converter stone slag, the material containing aluminum metal is added into the liquid converter stone slag, and the heat energy generated by the reaction of aluminum metal and oxygen is used as a heat source, so that the converter stone slag is not easily cooled due to insufficient heat source. Curing causes the upgrading to fail, thus improving the success rate of the converter gravel.

The invention will be described in detail below. The aluminum-containing metal material of the step (1) may be any material containing aluminum metal and suitable for upgrading the converter stone slag. Preferably, the aluminum-containing metal material is aluminum. Aluminium slag in industrial waste, such as aluminum slag produced in aluminum smelting operations.

Preferably, the weight ratio of the aluminum slag to the converter gravel ranges from 1:15 to 1:120. More preferably, the weight ratio of the aluminum slag to the converter gravel is 1:40.

Preferably, the aluminum slag contains 15 to 25 wt% of aluminum metal.

Preferably, the step (2) is carried out by the thermal energy generated by the reaction of the aluminum metal and the oxygen in the aluminum-containing metal material, and the reaction is as shown in the following formula (I): 4Al+3O ₂ → 2Al ₂ O ₃ + heat (I)

Preferably, the converter stone slag contains ferrous oxide, and step (2) is further heated by the heat energy generated by the reaction of ferrous oxide and oxygen, and the reaction is as shown in the following formula (II): 2FeO+1/2O ₂ → Fe ₂ O ₃ + thermal energy (II)

Preferably, the operating temperature range of the temperature-increasing converter gravel in step (2) is from 1380 ° C to 1530 ° C.

In the step (3), after the blast furnace is blown into the temperature-refined converter stone slag, the converter slag is modified by reacting CaO and strontium in the converter slag to react the slag compound, and the reaction is as follows (III): 2CaO + SiO ₂ → 2CaO. SiO ₂ (III)

In the step (3), the CaO in the converter stone slag is further modified by the iron oxide produced by the reaction between the ferrous oxide and the oxygen, and the reaction is as follows: (IV) and shown: 2CaO+Fe ₂ O ₃ → 2CaO. Fe ₂ O ₃ (IV)

The present invention will be further illustrated by the following examples, but it should be understood that this embodiment is intended to be illustrative only and not to be construed as limiting.

<Example 1> Modified converter stone residue

Step (1): Adding aluminum slag in the aluminum industry waste (the composition is as shown in Table 1 below) to the converter slag to be upgraded and liquid at an operating temperature of 1380 to 1530 ° C (aluminum slag: converter slag) The weight ratio is 1:40), and an aluminum-containing converter stone residue is obtained.

Step (2): inserting the oxygen lance into the aluminum-containing converter slag which is obtained in the step (1) and is still in a liquid state, blowing about 70-120 m ^{3 of} oxygen (the blowing time is about 20-35 minutes), so that the aluminum is made. The aluminum metal in the slag and the ferrous oxide in the converter stone slag react with oxygen to generate alumina, iron oxide and heat energy, respectively, and use the heat energy generated by the two reactions as a heat source to make the aluminum-containing converter stone residue After the temperature is raised to 1450~1530 °C, the temperature-controlled converter stone residue is obtained.

Step (3): blowing the heated furnace slag obtained in the step (2) into 2.4 to 4.0 tons of cerium (SiO ₂ ) (blowing time of about 20 to 35 minutes), so that the cerium is dissolved by heat, at this time, The CaO in the converter stone slag reacts with the cerium to form a phthalate compound (2CaO.SiO ₂ ) for modification, or CaO reacts with the iron oxide produced in the step (2) to form 2CaO. The Fe ₂ O ₃ is modified to obtain a modified converter stone residue.

<Example 2>

According to the preparation method of the first embodiment, the converter stone slag in the one station of the blowing and the second station of the blowing is respectively modified from October 1 to December 31, 101, and then the total number of barrels is counted separately, and When the blasting sand was blown, the heat was cooled due to insufficient heat source, and the heat of the converter slag was not able to be reformed (that is, the number of solidified barrels). The results are summarized in Table 2.

<Example 3>

In addition, from January 1 to July 30, 102, according to the preparation method of Example 2, the converter slag in the one station of the blowing and the two stations in the blowing station were respectively modified, and the conversion of the converter slag could not be performed. The number of curing barrels is shown in Table 2.

<Comparative example>

According to steps (2) and (3) in the preparation method of Example 1, respectively, that is, step (1) is not performed, respectively, the converter stone slag in the one-stop and two-blowing stations is modified, and then The total number of barrels is counted separately, and when the sand is blown, the heat is cooled due to insufficient heat source, and the converter stone cannot be used. The number of solidified barrels modified by slag was compiled in Table 2.

Table 2 shows that if aluminum slag is added to the converter slag before blowing oxygen, the curing ratio will be greatly reduced from 22.72% (without adding aluminum slag) to 2.97%, confirming the preparation method of the present invention, using aluminum slag The aluminum metal reacts with the blown oxygen to generate heat as a heat source to improve the temperature of the converter slag during the upgrading, so that it can be maintained in the state of liquid slag for a long time, and it is indeed effective to improve the converter caused by insufficient heat source in the conventional method. The problem is that the gravel is cooled and solidified and cannot be upgraded.

In summary, the modified converter grate of the present invention is prepared by adding the aluminum-containing metal material into the liquid converter stone slag during the upgrading process of the converter stone slag, so that the converter stone slag is not easily caused by insufficient heat source. The cooling and solidification causes the upgrading to fail, so that the success rate of the converter gravel upgrading is improved, so the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.

Claims (6)

A method for preparing a modified converter stone slag comprises the following steps: (1) adding a material containing aluminum metal to a liquid converter stone slag to obtain an aluminum-containing converter stone slag; and (2) in the aluminum-containing converter stone slag After the oxygen is blown, the temperature is raised to obtain a temperature-refining converter stone residue; and (3) the sand is blown into the temperature-controlled converter stone residue to be modified to obtain a modified converter stone residue. The method for preparing a modified converter stone slag according to claim 1, wherein in the step (1), the aluminum-containing metal material is aluminum slag in the aluminum industry waste, and the aluminum slag and the converter stone slag The weight ratio is 1:40. The method for preparing a modified converter stone slag according to claim 2, wherein the aluminum slag contains 15 to 25 wt% of aluminum metal. The method for preparing a modified converter stone slag according to claim 1, wherein the step (2) is to increase the temperature by the heat energy generated by the reaction of the aluminum metal and the oxygen in the aluminum-containing metal material. The method for preparing a modified converter stone slag according to claim 4, wherein the converter stone slag contains ferrous oxide, and the step (2) further increases the temperature by the heat energy generated by the reaction of ferrous oxide and oxygen. The method for preparing a modified converter stone slag according to claim 1, wherein the operating temperature range of the temperature-returning converter slag in the step (2) is 1380 to 1530 °C.