JPS63215532A - Production of rock wool raw material - Google Patents

Abstract

PURPOSE:To eliminate necessity of dissolving blast furnace slag containing blended natural ores at high temperature as in conventional methods and reduce reduction of production cost of high-grade rock wool, by regulating silicon removing treatment of molten iron by a specific method. CONSTITUTION:A raw material for rock wool is produced from slag after silicon removal by the following method (A) or (B). (A) The raw material is regulated to provide 10-30wt.% content of MnO and/or TiO2 and 0.2-0.8 weight ratio of CaO/SiO2 in components of slag formed by silicon removing treatment of molten iron. (B) The raw material is regulated to provide 10-30wt.% total contents of MnO and/or TiO2 and MgO and 0.2-0.8 weight ratio of CaO/SiO2 in components of slag formed by the silicon removing treatment of molten iron. The resultant slag produced by the silicon removing treatment according to the above-mentioned method (A) or (B) can be directly used as a raw material for rock wool.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a raw material for rock wool used for industrial and architectural insulation or sound-absorbing materials.

[Conventional technology]

In recent years, rock wool has come to be widely used as an artificial inorganic fiber to replace natural fibers, such as in insulation materials that require heat-resistant performance, and as sound-absorbing materials.

The main raw material for this rock wool is blast furnace slag, which is mixed with natural ores to improve fiber performance, melted in an electric furnace or cupola, and then heated using centrifugal force, compressed air, or high-pressure steam. Depending on the thickness, 3 to 10μ,
It is made into a fibrous material with a length of several tens of strips.

The properties of rock wool vary depending on the type of natural ore blended into the blast furnace slag, but the commonly used rock wool is made by blending approximately 10% of silica sand or silica stone into the slag to increase basicity (CaO/5iO2). 1 or less to give the fiber the necessary strength and weather resistance.

In addition, large amounts of basalt and andesite are mixed into the slag,
Alternatively, serpentine is mixed with silica sand or silica stone in the slag.
By blending with gO [gO], high-grade rock wool with a basicity of about 0.5, which is extremely lightweight and has excellent strength and heat resistance, is also produced.

[Problems to be solved by the invention] However, in order to melt blast furnace slag containing approximately 10% of silica sand or silica stone in a furnace, energy is required to raise the temperature to approximately 1500°C. This increases production costs.

In addition, when producing high-grade rock wool, the ratio of natural ore blended into the blast furnace slag increases, so melting requires even more energy to raise the temperature, making production costs even higher. Become.

[Means for solving problems]

The present inventors have been conducting research aimed at reducing the production cost of rock wool. As a result, the Si-removal process, which is carried out as a kind of pre-treatment for hot metal, involves placing the hot metal from the blast furnace in a ladle or the like before charging it into the steelmaking furnace, and blowing oxygen, iron ore, etc. into the hot metal to eliminate the Si in the hot metal. As shown in Table 1, it has been found that the components of the slag generated during the treatment to remove rock wool are similar to those of the natural basalt used in high-grade rock wool.

Table 1 As a result of repeated experiments in order to use the slag obtained through the desaturation treatment as a raw material for rock wool, iron sand and Mn ore were added to the hot metal as desaturation agents in place of the conventional oxygen. It has been found that the obtained slag can be used as a raw material for high-grade rock wool if the components satisfy the following conditions.

The basicity is 0.2 to 0.6, and the content of MnO and/or TiO is 10 to 30% by weight. In this case, MnO and Tie.

There is no problem even if the content of either of these is 0%.

In addition, slag obtained by adding ores that produce MgO, such as serpentine, together with the above-mentioned desiliconizing agent to the hot metal to be subjected to Si-removal treatment, can be made even lighter if the components satisfy the following conditions. It was found that it can be used as a raw material for high-grade rock wool.

The basicity is 0.2 to 0.6, and the total content of MnO and/or TiOx and MgO is 10 to 30% by weight. In this case, MnO and T
There is no problem even if the content of any one of i O weight is 0%.

That is, the present invention provides: +11 The content of MnO and/or T i Ot is 10 to 30% by weight and the weight ratio of CaO/SiO is 0.2 to 0.2 to 30% by weight in the components of the slag produced by the Si removal treatment of hot metal. A method for connecting fural raw materials in one step or two, characterized by adjusting the temperature to 0.8.

(2) The total amount of MnO and/or Tiet content and MgO content in the components of slag produced in the de-Si treatment of hot metal is 10 to 30% by weight and CaO/
This is a method for producing rock wool raw material from St-free slag, which is characterized by adjusting the weight ratio of S i Ot to 0.2 to 0.8.

In the first and second inventions, the weight ratio of CaO/SiOx is set to 0.2 to 0.8 because a certain amount of CaO is required for the Si removal treatment, and 0.2 to 0.8 is the weight ratio.
This is because if it is less than 2, the heat resistance temperature of the fiber will decrease significantly,
This is because if it exceeds 0.8, the fiber workability will decrease, such as an increase in the appropriate fiberization temperature and a decrease in the fiber ratio.

In the first invention, the content of MnO and/or T I Oz is limited to 10 to 30% by weight because if less than 10% by weight is added, there is almost no effect of improving fiber strength, and if the content exceeds 30% by weight, This is because the SiO3 content decreases as a result, and the workability of fiberization decreases.

In the second invention, the total amount of MnO and/or TtOx content and MgO content is limited to 10 to 30% by weight because less than 10% has little effect on improving fiber strength. If it exceeds 30% by weight, it will result in Sin.
, decreases, and the workability of fiberization decreases.

[For production]

According to the method of the present invention, natural ore added as a desiliconizing agent to hot metal to be subjected to a desiliconizing treatment is melted by the sensible heat of the hot metal and turned into slag. Therefore, by selecting the ore used as the Si-removal agent and its addition amount, the components of the slag produced in the Si-removal treatment can be adjusted to be suitable for high-grade rock wool. In this way, the generated slag can be immediately turned into fibers as it is, and unlike conventional methods, high-temperature energy for melting natural ores is not required.

〔Example〕

Examples will be explained below.

Regarding the invention examples Φ to ■.

250 tons of steelmaking pig iron having the chemical composition shown in Table 2 was charged into a ladle and subjected to Si removal treatment according to the method of the present invention to produce slag for rock wool.

In addition, all percentages indicate weight percent.

Table 2 Inventive example (■) uses 30 kr of iron sand/hot metal as a desiliconizing agent.
n, and 30 pupils of Mn ore/molten tAton were added into the hot metal.

Example ① of the present invention uses 30kr of iron ore/t of hot metal as a desiliconizing agent.
on was added to the hot metal.

Inventive example ① uses iron sand 40kr/hot metal to
n was added into the hot metal.

In Example (2) of the present invention, 40 kt of Mn ore/ton of hot metal was added to the hot metal as a desiliconizing agent.

Example ① of the present invention uses 30 kr of iron sand/hot metal as a desiliconizing agent.
n was added to the hot metal, and 20 kir of serpentine/ton of hot metal was added.

Inventive example (2), Mnn was added as a de-S and i agent to the hot metal at 30 kr/ton of hot metal, and 20 kr/ton of serpentinite was added to the hot metal.
A ton of hot metal was added.

Example ① of the present invention uses 30 kr of iron sand/hot metal as a desiliconizing agent.
In addition to adding n to the hot metal, 20 kr of serpentine/ton of hot metal was added.

Next, the generated molten slag is made into fibers by centrifugal force,
After making rock wool, the properties of each rock wool were investigated. The results are shown in Table 4.

Regarding comparative example ■.

Blast furnace hot metal slag having the chemical components shown in Table 3 and silica sand as a component regulator were mixed at a ratio of 90% blast furnace hot metal slag and 10% silica sand, and melted in an electric furnace.

Table 3 After this molten metal was made into fibers by centrifugal force and made into rock cool,
We investigated its properties. The results are shown in Table 4.

Regarding comparative example ■.

Blast furnace hot metal slag with the chemical components shown in Table 3 and silica sand and serpentine as component regulators were mixed with 56% blast furnace hot metal slag and 2 silica sand.
4% and 20% serpentine were mixed and melted in an electric furnace. This molten metal was made into rock wool by centrifugal force, and its properties were investigated. The results are shown in Table 4.

As shown in Table 4, the rock wools of Examples ■ to ■ of the present invention all have lower densities than Comparative Example ■, and are as light or lighter than Comparative Example ■, which is conventional high-grade rock wool. It is. Furthermore, Examples 1 to 2 of the present invention are superior to Comparative Example 2 in terms of strength and heat resistance, and have performance equivalent to or better than Comparative Example 2. Furthermore, examples of the present invention Φ～■
For example, compared to Comparative Examples ① to ②, the number of units of heat source required for melting the raw material is extremely small.

〔Effect of the invention〕

As explained above, the present invention uses natural ores that improve fiber performance as a desulfurization agent for hot metal, and these natural ores are melted by the sensible heat of the hot metal and slag during the desiliconization process.
Since the slag is turned into slag, the slag produced by the Si-removal treatment directly serves as a raw material for rock wool. Therefore, there is no need to melt blast furnace slag mixed with natural ores at high temperatures as in the past, and the production cost of high-grade rock wool can be lowered.

Claims (2)

[Claims] (1) The content of MnO and/or TiO_2 in the components of slag produced in the de-Si treatment of hot metal is 10 to 3.
0% by weight and the weight ratio of CaO/SiO is 0.2 to 0.
．． 8. A method for producing rock wool raw material from a Si-free slab. (2) The total content of MnO and/or TiO_2 and MgO in the components of slag produced in the de-Si treatment of hot metal is 10 to 30% by weight and CaO/SiO
A method for producing rock wool raw material from Si-free slag, characterized by adjusting the weight ratio of _2 to 0.2 to 0.8.