JP4475635B2 - Recycling method to recycle unfired bricks mainly composed of alumina components and refractories after use of alumina / carbonaceous materials to unfired bricks mainly composed of alumina components - Google Patents

Description

  The present invention relates to a regeneration method for regenerating unfired bricks mainly composed of alumina components and alumina / carbonaceous used refractories into unfired bricks mainly composed of alumina components, and in particular, alumina / carbonaceous used refractories. The present invention relates to a novel improvement for processing at a high efficiency and low cost by pulverizing to a particle size of 3 mm or less.

  Conventionally, various methods for recycling used refractories have been devised and actually used.

  For example, regarding the processing method of used refractories for recycling, for example, as described in Patent Documents 1, 2, 3, etc., the removal of bullion, slag infiltrating layer, etc. is performed, and used refractory Development of treatment methods aimed at increasing the purity of products has been carried out.

In addition, as described in Patent Documents 4 and 5, as a method of utilizing the alumina / carbonaceous spent refractory (hereinafter referred to as AC scrap) according to the present invention, coarse particles and fine powder portions excluding fine powder portions are used. There are a method applied to an amorphous refractory and a method applied to a precast block without performing any pulverization treatment as described in Patent Document 6.

JP 2002-206867 A JP 2003-88845 A JP 9-328354 A JP 2002-201080 A JP-A-10-287474 JP 11-28561 A

Since the conventional method is configured as described above, the following problems exist.
In other words, if the slag infiltrated layer is completely removed from the used refractory, and the purification of these slag infiltrates is excessive, there is a cost for processing the equipment and the separated slag infiltrated layer, resulting in the used refractory. It is difficult to obtain cost merit when using.

  In addition, when used for irregular refractories, it is necessary to subdivide the grain size of the refractory after processing in order to ensure or maintain the workability, and there is a problem that it is difficult to use the fine powder part. . Further, depending on the characteristics of the pulverization equipment, the pulverized product may not be balanced with the required particle size, and only a certain particle size may be excessive. In particular, the AC waste to be recycled this time contains carbon, so it is particularly difficult to use the fine powder portion from the viewpoint of workability and oxidation resistance.

  Also, as described in Patent Document 6, when the alumina / carbonaceous used refractory is subjected only to deironing and applied to a precast block for hot water contact parts, the above-mentioned high processing costs, fine powder parts, etc. However, the amount of used refractory is limited, and as a result, it is difficult to consume all of the generated amount.

The non-fired brick refractory mainly composed of an alumina component according to the present invention is mainly composed of an alumina component having 40 to 80 wt% of a pulverized product obtained by pulverizing an alumina / carbonaceous used refractory to a particle size of 3 mm or less. in the unfired bricks refractory, to the pulverized product, purity granularity than 90 wt% or less of Ma magnesia fine material 0.074mm is added 3～10Wt%, and a virgin material, natural scaly graphite pitch comprises more becomes mosquitoes Bon pulverized material either carbon black, in the configuration of carbon fines material was added so the carbon component total content of carbon in alumina carbon debris is 9～13Wt% In addition, the alumina / carbonaceous spent refractory according to the present invention can be regenerated into non-fired bricks mainly composed of alumina components. The method is a non-fired alumina / carbon refractory used mainly of alumina component, using 40-80 wt% of a pulverized product obtained by pulverizing alumina / carbon refractory used to a particle size of 3 mm or less. in the reproducing method of reproducing the bricks, to the pulverized product, purity granularity than 90 wt% or less of Ma magnesia fine material 0.074mm is added 3～10Wt%, and a virgin material, natural scaly graphite pitch comprises more becomes mosquitoes Bon pulverized material either carbon black, carbon component total content of carbon in alumina carbon debris is a method of adding carbon fine material so that 9～13Wt% .

Since the non-fired brick mainly composed of the alumina component according to the present invention and the regeneration method for regenerating the alumina / carbonaceous spent refractory into the non-fired brick mainly composed of the alumina component are configured as described above, Such effects can be obtained.
That is, by using a brick added with 40 to 80 wt% of AC waste pulverized to a particle size of 3 mm or less by the above-described method, it is possible to recycle without discarding the used alumina / carbon refractory. Become.
By simplifying the treatment process of the used refractory, the spent refractory can be blended and added as an inexpensive recycled raw material, so that the raw material cost of the refractory can be reduced.
When adding AC scrap to unfired brick, paying attention to the amount of magnesia raw material and carbon raw material added to the virgin raw material part, adding both raw materials is equivalent to conventional non-fired brick not using AC waste. The durability is obtained, and as a result, the amount of used refractories is increased due to the increase in the basic unit, and the AC waste can be recycled without increasing the cost.

  The present invention produces non-fired bricks refractory mainly composed of alumina components using AC scraps pulverized to a particle size of 3 mm or less, so that non-fired by recycling using the same kneading, molding and drying methods as before. The purpose is to make brick.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a non-fired brick mainly composed of an alumina component according to the present invention and a regeneration method for reclaiming an alumina / carbonaceous used refractory material into an unfired brick mainly composed of an alumina component will be described below with reference to the drawings.

The present invention does not require separation / removal of the slag infiltrating layer and fragmentation of the particle size in the pulverization process in the treatment of the alumina / carbonaceous used refractories, and uses all the fine powder portions generated during pulverization. This is a technique for blending and adding AC waste to non-fired bricks (hereinafter referred to as non-fired bricks) mainly composed of alumina components for the purpose of reducing processing costs and reducing the amount of waste.

Specifically, the used alumina / carbon refractory is roughly crushed, magnetically selected, and further pulverized to a particle size of 3 mm or less by secondary pulverization, and recycled as a part of the raw material of unfired brick. The reason for pulverizing to 3 mm or less is to suppress variation in brick formability due to segregation of AC scrap particle size. In addition, when the particle size distribution when pulverized to 3 mm or less is extremely biased, the amount of addition is limited, so that pulverization is desirably performed so that 3-1 mm = 40-60 wt%, less than 1 mm = 60-40 wt%. The machine should be adjusted. In addition, it is better to adjust the pulverizer in order to suppress variation in the particle size distribution among the pulverization lots.

The compounding addition amount of AC (alumina carbon) waste is 40 to 80 wt%. About addition amount, it adjusts with the severity of the site | part in which a brick is used (slag line (SL), free board (FB) part = 40-60 wt%, metal line (ML) part = 60-80 wt%)).

The addition method is performed by replacing the virgin raw material in the unfired brick, which corresponds to the particle size of AC waste. This particle size range is usually composed of one or more of brown alumina, natural high alumina, bauxite, white fused alumina, sintered alumina, mullite, sintered magnesia, and fused magnesia.

  Conventionally, AC scrap is mainly made of a high-purity alumina raw material, and a carbon raw material is added. For this reason, when used as a recycled material, the sinterability with other virgin materials is low. For example, there is no problem if the magnesia raw material is originally blended and added, such as unfired alumina, magnesia, and carbon brick, but for example, magnesia raw material is blended and added, such as unfired alumina, carbon dioxide, and carbon brick. For materials that do not exist, it is necessary to add and add a new magnesia raw material. This is to add sinterability by spinel formation with AC scrap and alumina content in the virgin raw material by adding the magnesia raw material. Even if unfired alumina, magnesia, and carbon brick are used, if the magnesia raw material is not used in the fine powder part, it is necessary to add the fine powder part for the same reason. The magnesia raw material to be added in the fine powder part is sintered magnesia or electrofused magnesia, the purity is 90 wt% or more, and the addition range is 3 to 10 wt%. If the purity is 90% or less, there is a problem in terms of corrosion resistance, and if the addition amount is 3wt% or less, the effect is not obtained, and if it is 10wt% or more, the surface is spalling resistance due to excessive sintering and expansion. There is a problem.

AC scrap contains carbon, but in addition to this, carbon as a virgin raw material is added. This is because, when attempting to obtain the effect of suppressing slag infiltration by carbon, it is desirable that the carbon is fine powder, and it is difficult to obtain this effect only with the carbon source in the fine powder portion in the AC scrap. The amount of carbon added as a virgin raw material is in the following range. The carbon raw material to be used may be any of natural scaly graphite, pitch, and carbon black.
Carbon content in brick = 9 wt% <carbon content in AC scrap + virgin carbon raw material <13 wt%

  As an antioxidant for carbon in the AC scrap and virgin carbon material, one or more of metal aluminum, metal silicon, and B4C are used.

  Molding aids (clays, etc.) and binders (thermosetting resins such as phenolic resins) required for formability and product strength by pressing of bricks are the same as ordinary non-fired bricks, and the rest is ordinary Same as fired brick.

Next, the case of the present invention actually tested and the comparative example will be disclosed.
In addition, AC scraps pulverized to a particle size of 3 mm or less were blended and added to non-fired alumina, charcoal silica, and carbon bricks used as a side wall work material of a hot metal pretreatment pan (dephosphorization and desulfurization treatment pan). Table 1 in Table 1 lists each formulation for which actual furnace evaluation was performed.

  Next, the amount of AC scrap added was 40 to 60 wt% for bricks for slag line portions and freeboard portions, and 60 to 80 wt% for bricks for metal line portions, and actual furnace evaluation was performed.

  In this example, AC scrap was added to unfired alumina, carbonaceous silica, and carbon brick, so a magnesia raw material was newly added. As the magnesia raw material, electrofused magnesia having a purity of 95% was used in each example with a particle size of 0.074 mm or less.

  Each formulation described in Table 1 of Table 1 will be described. Comparative Example 1 is a non-fired alumina / charcoal / carbon brick that is normally used without AC waste added. In Examples 1 to 4, 40 to 80 wt% of AC waste was added, and magnesia raw materials and carbon raw materials were used within the scope of the present invention. In Comparative Examples 2, 3 and 4, AC scrap was added, and the carbon content and the magnesia addition amount were added beyond the claims of the present invention.

In the metal line part of Example 4, the AC scrap addition amount was 80 wt%. Since the magnesia raw material and the carbon raw material are added to the remainder of the addition of the molding aid necessary as a virgin raw material for forming the brick, these addition amounts are smaller than those of the other examples.
In addition, in FIG. 1, the result of the actual furnace evaluation of each compounding described in Table 1 of Table 1 is shown.

  The main cause of the damage was melting loss of the slag line part in each of Examples 1 to 4 and Comparative Examples 1 to 3, and Comparative Example 4 was close cracking of the slag line part metal line part. Further, the remaining size of the non-cracked portion in Comparative Example 4 was equivalent to that in Example 2.

  The service life of Comparative Example 1 was 400 ch, whereas the same service life of Examples 1 to 4 was obtained.

  When Example 1 and 2 are compared, since the direction of Example 2 with much magnesia addition amount is excellent in durability, the effect by magnesia addition can be confirmed.

  In Comparative Example 2, since the carbon content exceeded the range of the present invention, sufficient durability could not be obtained due to a decrease in corrosion resistance. This is because the moldability is reduced due to an excessive amount of carbon, and the physical properties are inferior to those of Comparative Example 1 and Examples 1 to 4.

  Comparative Example 3 Since the added amount of magnesia is less than the range of the invention, sufficient corrosion resistance cannot be obtained. Conversely, since Comparative Example 4 is more than the range of the present invention, there is a problem in the spalling resistance. The service life of both 3 and 4 decreased. Moreover, since the remaining size at the time of discard of Comparative Example 4 was not different from Example 2, it was found that improvement in corrosion resistance cannot be expected even when the amount of magnesia added exceeds 10 wt%.

  Therefore, according to the present invention, non-fired mainly composed of an alumina component characterized by having 40 to 80 wt% of a pulverized product obtained by pulverizing alumina / carbonaceous used refractory to a particle size of 3 mm or less. Brick refractory can be obtained, unburned brick refractory mainly composed of an alumina component characterized by adding a magnesia fine powder raw material and a carbon fine powder raw material to the pulverized product, Furthermore, the non-fired brick to which the carbon fine powder raw material is added so that 3 to 10 wt% of the magnesia fine powder raw material is added and the carbon component content is 9 to 13 wt% can be obtained.

  The present invention is not limited to brick refractories used in the iron making process, but can be applied to the use of buildings, grounds, and the like.

It is a characteristic view which shows the actual furnace durable times result of the non-fired alumina, the carbon silica, and the carbon brick which recycled AC waste by this invention.

Claims (2)

In the non-fired brick refractory mainly composed of an alumina component having 40 to 80 wt% of a pulverized product obtained by pulverizing alumina / carbonaceous used refractory to a particle size of 3 mm or less,
With respect to the pulverized product, purity granularity than 90 wt% or less of Ma magnesia fine material 0.074mm is added 3～10Wt%, and natural scaly graphite is virgin material, pitch, from one of carbon black The carbon fine powder raw material is added, and the carbon fine powder raw material is added so that the total carbon component content with the carbon in the alumina / carbon scrap is 9 to 13 wt%. Fired brick refractory. Alumina / carbonaceous used refractory that uses 40-80 wt% of pulverized product obtained by grinding alumina / carbonaceous refractory to a particle size of 3 mm or less as a raw material is recycled into non-fired bricks mainly composed of alumina components. In the playback method to
With respect to the pulverized product, purity granularity than 90 wt% or less of Ma magnesia fine material 0.074mm is added 3～10Wt%, and a virgin material, natural scaly graphite, pitch, than any of the carbon black comprising Ca Bon include pulverized raw material, the carbon to the sum of the carbon component content 9～13Wt% become so carbon fine raw material alumina carbonaceous spent refractory, characterized in that the addition of the alumina-carbon debris A recycling method for regenerating a non-fired brick mainly composed of an alumina component.

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