KR101482329B1 - Fill-up Materials using iron and steelmaking slag - Google Patents

Abstract

The present invention relates to a coarse aggregate slag, a fine aggregate slag, a fine aggregate slag, And at least one selected from the group consisting of a desulfurization slag, a disinfection slag, and a gypsum.
Since the embankment of the present invention uses a by-product of the steel making process, unlike the conventional embankment using natural aggregate, environmentally friendly and long-term steelmaking slag requiring aging is not used, Less.
Further, by using the water-resistant water-based slag of the present invention as a fine aggregate, the bonding strength between the coarse aggregate and the fine aggregate is increased, so that the compressive strength of the embankment can be improved, and the desulfurized slag, And reacts with the SiO ₂ contained in the coal slag to produce a hydrated body of CaO-SiO ₂ -H ₂ O and CaO-Al ₂ O ₃ -CaSO ₄ -H ₂ O, Lt; / RTI >

Description

{Fill-up Materials using iron and steelmaking slag}

The present invention relates to an embankment containing slag and slag generated from a steelmaking process as a coarse aggregate and a fine aggregate, and a desulfurization slag and a descaling slag and a gypsum generated in a steelmaking process.

Various kinds of materials are used for various construction works, and the most of them are consumed the most, and the materials used in various fields as basic essential materials are embossed materials. As the embankment material, soil which is a natural material in almost all fields has been used up to now. Generally speaking, the soil mentioned in the construction includes silt, clay, sand and gravel.

However, when landfill sites are developed and used as embankment materials for embankment construction, there arises a problem of the cost of forest restoration after the destruction of the environment due to the development of the deodorant and the development and use of the deodorant. Recently, some artificial embankment materials have been used as a countermeasure for this problem, but most of them are simple substitutes replacing only a small amount of existing embankment materials. Therefore, there are problems that can not be solved in terms of conservation of natural environment and economical efficiency. Therefore, it is urgent to develop a new embankment material which can replace the existing clay material, natural soil material.

Accordingly, a method of using steelmaking slag, blast furnace slag, or FINEX slag, which is generated in a steelmaking process, as embankment material may be suggested. However, since steelmaking slag has a high basicity (CaO / SiO ₂ content ratio) of at least 2.0 and is not stable against expansion, it is necessary to cure for 6 months or more, or to perform aging treatment with steam or autoclave . In addition, due to differences in composition depending on the type of steel produced, there is a large variation in quality, and since the pH is high due to a high CaO content, attention must be paid to the influence on the surrounding environment.

Meanwhile, the blast furnace slag may be divided into a bulk material slag obtained by air-cooling treatment according to a cooling method and a water-based slag obtained by water-cooling treatment. The bulk material slag is generated in a massive form, It is an eco-friendly material that has been used as ash. In addition, since the basicity is as low as 1.2 to 1.4, it has a very high stability against expansion. Thus, it is mixed with steel slag and used in the form of composite slag or as an embankment or lozenge.

In addition, FINEX slag is similar in properties to blast furnace slag. Expansion tests on FINEX slag showed 0.02% similar to blast furnace slag, which is much lower than the expansion standard value of 1.5% for embankment and mortar. In addition, since Finex slag is similar to blast furnace slag in that it has low basicity, it can be said that utilization as fine aggregate for civil engineering is very high.

However, when a soft foundation or an upper structure, which is expected to have a large settlement after embankment, is sensitive to expansion or subsidence due to embankment, a higher bond strength than that of general embankment is required. Therefore, It is difficult to use in the form of composite slag with slag. In this case, the prefact concrete method in which cement grouting is performed after coarse aggregate is installed can be used, but this requires a high cost.

Therefore, the bond strength is higher than that of general embankment, so natural settlement after embankment is very low, and economic and environmentally friendly alternative embankment is required.

One aspect of the present invention relates to a method for producing a steel slag, comprising the steps of using a carbonaceous slag and a water-based slag produced in a steelmaking process as a coarse aggregate and a fine aggregate, and adding a desulfurization slag, High strength is exhibited in a short period of time, natural settlement after embankment is very low, and economical and eco-friendly embankment is provided.

The present invention relates to a coarse aggregate slag, a fine aggregate slag, a fine aggregate slag, And at least one selected from the group consisting of a desulfurization slag, a disinfection slag, and a gypsum.

The carbonaceous slag may be a blast furnace slag, a Finike mortar slag, or a mixture thereof.

The water-borne slag may be blast furnace slag, fine-fin water slag or a mixture thereof.

The gypsum may be at least one selected from aquatic gypsum, semi-gypsum and anhydrous gypsum.

1 to 5 parts by weight of water-borne slag with respect to 100 parts by weight of the embankment; 1 to 5 parts by weight of a stimulus material, and a residual carbonaceous material slag.

Since the embankment of the present invention uses a by-product of the steel making process, unlike the conventional embankment using natural aggregate, environmentally friendly and long-term steelmaking slag requiring aging is not used, Less.

Further, by using the water-resistant water-based slag of the present invention as a fine aggregate, the bonding strength between the coarse aggregate and the fine aggregate is increased, so that the compressive strength of the embankment can be improved, and the desulfurized slag, And reacts with the SiO ₂ contained in the coal slag to produce a hydrated body of CaO-SiO ₂ -H ₂ O and CaO-Al ₂ O ₃ -CaSO ₄ -H ₂ O, Lt; / RTI >

Hereinafter, preferred embodiments of the present invention will be described. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art.

The present invention relates to an embankment comprising a carbonaceous slag and a water-based slag generated in a steelmaking process as an aggregate, and a desulfurization slag and a ginseng slag generated in the steelmaking process as gypsum. When the water-based slag, which is a fine aggregate, is mixed between the bulked slag used as the coarse aggregate, the bonding strength between the coarse aggregate and the fine aggregate increases due to the hydraulic property of the water-based slag, In addition, by adding at least one kind selected from the desulfurization slag, the de-phosphorus slag and the gypsum to the embankment with the stimulus material, the bonding strength can be improved within a short period after embankment.

The carbonaceous slag is a massive slag in which the slag is subjected to air-cooling treatment. Since the basicity (CaO / SiO ₂ ratio) is as low as 1.2 to 1.3, there is less concern about aggregate expansion. When the basicity is 2 or more, 3CaO · SiO ₂ may be generated in the crystal phase constituting the slag. The 3CaO · SiO _2, which is the case because the hydraulic steel is contained in a large amount of aggregate, the aggregate is unstable may occur aggregate destroyed by hydration expansion.

Also, 3CaO · SiO ₂ component when cooled from a molten state, may be decomposed to 2CaO · SiO ₂ with a free CaO (CaO-free), such decomposition is liable to occur if the gradual cooling of the molten slag. Therefore, when the basicity is high to at least 2, 3CaO · SiO ₂ is decomposed in the slowly cooled steelmaking slag aggregate, and a large amount of free CaO can be produced. The free CaO is converted into Ca (OH) ₂ by hydration to expand the volume to about 2.2 times, causing aggregate expansion. In the case of severe aggregation, aggregate destruction may occur, and the utilization of aggregate as aggregate is reduced.

Unlike the case where the steel slag is used as an aggregate, the agglomerated slag has a low basicity, and therefore it is advantageous in that it is not subject to time and space restriction because long aging is not required. There is no particular limitation on the kind of the above-mentioned sawdust slag, but it is possible to use a blast furnace slag, a Finish sawdust slag, or a mixture thereof.

The water-bearing slag is a water-cooled slag which is quenched, and serves to fill the gap between coarse aggregates. Since the water-borne slag has hydraulic properties, it reacts with moisture between coarse aggregates to fill the voids and increase the bond strength between the coarse aggregates. The kind of the water-based slag is not particularly limited, and blast furnace slag, FINEX water-based slag, or a mixture thereof can be used.

The water-based slag may be included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the whole filler metal. When the water-borne slag is contained in an amount of less than 1 part by weight, it is not easy to fill the void because the ratio of the fine aggregate is smaller than that of the coarse aggregate slag or the fine-kernel slag, which is a coarse aggregate. Also, due to the lack of fine aggregate, the hydraulic strength is weakened and the bond strength between the coarse aggregate and the fine aggregate is hardly increased. On the other hand, when the water-borne slag is contained in an amount exceeding 5 parts by weight, the bond strength is not further increased and the economical efficiency is lowered.

As in the case of the embankment of the present invention, when a high strength bond strength is required in a short period of time after laying an embankment, or when a soil strengthening performance capable of reducing natural settlement is required, a long time is required for the embankment strength to be manifested, When the compaction is incomplete, the natural settlement may be large. Therefore, in addition to using the above-mentioned carbonaceous material slag and water-based material slag as an aggregate, a stimulus material capable of expressing the bond strength between the aggregate materials in a short period of time should be added. The filler of the present invention may contain at least one selected from the group consisting of a desulfurization slag, a dephosphorization slag, and a gypsum as a magnetic pole material, thereby enhancing the bonding strength between the aggregates.

The CaO component contained in the desulfurization slag, the de-phosphorus slag, or the gypsum may be SiO ₂ contained in the blast furnace or FINEX slag To form a CaO-SiO ₂ -H ₂ O hydrate. Also, CaSO ₄ contained in the gypsum reacts with the Al ₂ O ₅ component and the CaO component contained in the blast furnace or FINEX slag to form a CaO-Al ₂ O ₅ -CaSO ₄ -H ₂ O hydrate. The hydrate can fill the voids and improve the bonding strength between the aggregates, thereby reducing the natural settlement of the embankment. The kind of the gypsum is not particularly limited, and may be at least one kind selected from gypsum, semi-gypsum and anhydrous gypsum.

The magnetic pole material may be included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the whole filler metal. When the magnetic pole material is less than 1 part by weight, it is difficult to express the high strength of the embedding material in a short period of time due to the lack of the Al ₂ O ₅ component and the CaO component, which are alkaline components forming the hydrated body by stimulating the slag. If the amount is more than 5 parts by weight, a hydrated body is produced in a large amount, and the expandability of the embankment becomes excessive, so that cracks may occur after the embankment is hardened.

Hereinafter, the present invention will be described more specifically by way of specific examples. The following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited thereto.

[Example]

[Example 1]

The aggregate was mixed with the composition ratio of the embalming material in Table 1 below, and the embedding material of Example 1 was prepared such that the water content was 11%. The above-mentioned embedding material was ground in a 10x20 cm cylinder mold in three stages, and then cured at 20 ° C for 3 days and 28 days, and the compressive strength was measured. In addition, the above-mentioned embedding material was melted in a CBR molder, followed by lapse of 10 days at 80 DEG C, and then the water swelling ratio was measured.

division Composition of fillets (%) 3 days
Compressive strength
(MPa) 28th
Compressive strength
(MPa) Soaking
Expansion ratio
(%) Example 1 Blast furnace (95) + blast furnace (3) +
Desulfurization slag (2) 1.2 10.5 0.02 Example 2 Blast furnace (95) + blast furnace (3) +
Stainless steel slag (2) 1.3 11.6 0.02 Example 3 Blast furnace (95) + blast furnace (3) +
Gypsum plasterings (2) 1.5 14.3 0.02 Comparative Example 1 Blast furnace (93) + blast furnace (7) 0.1 4.1 0.02 Comparative Example 2 Blast furnace (90) + Blast furnace (0) +
Anhydrous gypsum (8) + Elastin slag (2) 0.8 8.5 0.56

[Examples 2 and 3]

The embankment was manufactured in the same manner as in Example 1 except that the composition ratio of the embankment was changed as shown in Table 1, and the 3-day compressive strength, the 28-day compressive strength and the water-swell ratio were measured.

[Comparative Examples 1 and 2]

The embankment was manufactured in the same manner as in Example 1 except that the composition ratio of the embankment was changed as shown in Table 1, and the 3-day compressive strength, the 28-day compressive strength and the water-swell ratio were measured.

As can be seen from the above Table 1, the embankment materials of Examples 1 to 3 were obtained by using blast furnace slag and blast furnace slag as aggregate, and using 1 to 5 parts by weight of desulfurization slag, descaling slag or anhydrous gypsum as a magnetic pole material , It was found that the initial strength and the long term strength were improved without increasing the water swelling ratio.

On the other hand, when the blast furnace slag was not added with the magnetic pole material as in Comparative Example 1, the initial strength was lower than in Examples 1 to 3. In addition, as in Comparative Example 2, when the magnetic pole material exceeds 5 parts by weight, a large amount of CaO-Al ₂ O ₅ -CaSO ₄ -H ₂ O hydrate is produced to increase the water swellability. Therefore, It is difficult to utilize it in rooftop construction and it is difficult to achieve the object of the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be obvious to those of ordinary skill in the art.

Claims (5)

With respect to 100 parts by weight of the embedding material,
1 to 5 parts by weight of water-resistant slag as a fine aggregate; 1 to 5 parts by weight of a magnetic pole material containing at least one kind selected from desulfurization slag, demineralized slag and gypsum, and an aggregate slag as a coarse aggregate.
The fillet according to claim 1, wherein the carbonaceous slag is a blast furnace slag, a whiteness slag, or a mixture thereof.
The filler according to claim 1, wherein the water-borne slag is a blast furnace slag, a FINEX water-bearing slag, or a mixture thereof.
The embankment as set forth in claim 1, wherein the gypsum is at least one selected from aquatic gypsum, semi-gypsum and anhydrous gypsum.
delete