KR101461788B1 - Method for treating fill-up materials using steelmaking slag - Google Patents

Abstract

The present invention provides a method for treating an embankment with a steel slag for spraying a solution containing Ca (OH) ₂ , CaCO _3, or a mixture thereof in an embankment containing iron-based slag as an aggregate.
By using the method of treating the embankment with steel-making slag according to the present invention, it is possible to reduce time and space requirements for aging of steel-making slag, and by forming a hydration body on the surface of steel-making slag aggregate and the gap between aggregates, The natural settlement amount can be reduced. In addition, it is possible to reduce odor, black turbid water, and scattered dust generated during embankment work.

Description

Technical Field [0001] The present invention relates to a method for treating an embankment with steel slag,

The present invention relates to a method for treating an embankment with steel slag generated in a steel making 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, it is possible to reduce the cost by using blast furnace slag or fine-scale slag as seasonal slag, but it is necessary to carry out long-term natural curing for 3 months or more in order to prevent the occurrence of wastewater in the embankment process. In addition, there is a problem that foul odor is generated due to the component of iron sulfide contained in the blast furnace or the FINEX lump slag, and scattered dust is generated during embankment work.

[Prior Patent Literature]
Korean Registered Patent No. 10-1188190 (Oct.
Korean Patent Publication No. 10-2000-0020548 (Apr. 15, 2000)

One aspect of the present invention is to provide a method for manufacturing a steel slag, which comprises sprinkling a solution containing Ca (OH) ₂ , CaCO _3, or a mixture thereof in an embankment using steel slag, To provide a processing method of embankment which can perform embankment work without curing. The present invention also provides a treatment method for reducing black turbid water and odor generated in embankment work.

The present invention provides a method for treating an embankment with a steel slag for spraying a solution containing Ca (OH) ₂ , CaCO _3, or a mixture thereof in an embankment containing iron-based slag as an aggregate.

The seasonal slag may be a sponge slag.

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

The solution containing Ca (OH) ₂ , CaCO ₃ or a mixture thereof is prepared by adding Ca (OH) ₂ , CaCO ₃ or a mixture thereof to 100 ml of water 0.01 g to 0.5 g.

The method of treating the embankment with the granular slag may be such that a solution containing Ca (OH) ₂ , CaCO ₃ or a mixture thereof is sprayed in an amount of 5 to 10 parts by weight per 100 parts by weight of the embankment.

The steel slag may have a particle size of 50 mm or less.

By using the method of treating the embankment with steel-making slag according to the present invention, it is possible to reduce time and space requirements for aging of steel-making slag, and by forming a hydration body on the surface of steel-making slag aggregate and the gap between aggregates, The natural settlement amount can be reduced. In addition, it is possible to reduce odor, black turbid water, and scattered dust generated during embankment work.

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 a method for treating an embankment with steel-making slag, and more particularly, to a method for spraying a solution containing Ca (OH) ₂ , CaCO ₃ or a mixture thereof into an embankment containing steel slag as an aggregate. The method for treating an embankment of the present invention relates to a method for treating an embankment which can prevent ground bumps and subsidence by reinforcing the ground with only the embankment without reinforcing the embankment with a high strength pile.

The above-mentioned embankment is not particularly limited, but includes steel slag as an aggregate, and may further include other components. The steel-making slag may be a garnet slag, and the blast furnace slag is not particularly limited, but may be granulated slag having a basicity (CaO / SiO ₂ ratio) of about 1.2 to 1.3 or a whiteness slag.

When the basicity is as low as 1.2 ~ 1.3, there is no concern about the expansion of the slag aggregate. Unlike steelmaking slag, since there is no free CaO in the slag, it does not need to be cured for a long time. There is an advantage in that the space is less restricted.

However, when it is used as high - performance embankment with higher load - bearing strength and lower natural settlement, it takes a long time after embankment, and natural settlement may be large when compaction is incomplete in embankment.

In order to solve this problem, a solution containing Ca (OH) ₂ , CaCO ₃ or a mixture thereof in an embankment containing blast furnace slag or fine lump slag is sprayed at the time of embankment work. The method of spraying is not particularly limited, but it can be sprayed using a spray tank used for reducing scattered dust or controlling water content of embankment during embankment work, for example.

The CaO component contained in the solution containing Ca (OH) ₂ , CaCO _3, or a mixture thereof may be SiO ₂ contained in the blast furnace or FINEX slag To form a CaO-SiO ₂ -H ₂ O or CaO-Al ₂ O ₃ -H ₂ O hydrate on the surface of the aggregate slag aggregate and the pores between the aggregates. The hydrate can fill the voids and improve the bonding strength between the aggregates, thereby reducing the natural settlement of the embankment.

The solution containing Ca (OH) ₂ , CaCO ₃ or a mixture thereof is prepared by adding Ca (OH) ₂ , CaCO ₃ or a mixture thereof to 100 ml of water 0.01 g to 0.5 g. If less than 0.01g in a space between the Ca ⁺² concentration is low, lump ore slag aggregate surface and aggregate in the solution or CaO-SiO ₂ -H ₂ O _{CaO-Al 2 O 3 -H 2} O hydrated body is hard to be formed, the aggregate load after compaction It is difficult to expect an increase in the load strength. If it exceeds 0.5 g, Ca (OH) ₂ or CaCO ₃ When the solution is sprinkled on the surface of the embankment, scattering dust of Ca (OH) ₂ or CaCO ₃ may excessively occur on the surface of the embankment, and this is not preferable from the viewpoint of cost.

The solution containing Ca (OH) ₂ , CaCO ₃ or a mixture thereof may be sprayed with 5 to 10 parts by weight per 100 parts by weight of the embankment. When the amount is less than 5 parts by weight, the water content of the embankment tends to be lower than the optimal water content, so that the compaction is not good and it is difficult to expect an increase in the load-carrying strength because the Ca ⁺² content in the solution is low. If the amount exceeds 10 parts by weight, the water content of the fillet exceeds the optimum water content, and the solution may flow over the surface layer of the upper surface of the embankment and overflow to the surface, which is not preferable.

Sulfur (FeS, FeS2) sulfides are present in coke or iron ores during the reduction process in the blast furnace slag or fine powder of the steel by-product. The content of the sulfur component is not particularly limited, but is about 0.6 to 1.4 parts by weight based on 100 parts by weight of the slag. Owing to such iron sulfide components, odor or wastewater such as sulfur odor may be generated when the coal slag is manufactured or used as an embankment. In order to prevent or reduce such a phenomenon, conventionally, the cement slag is cured to expose it in the air and then used.

However, when a solution containing Ca (OH) ₂ , CaCO ₃ or a mixture thereof is sprinkled on the above-mentioned embankment, since the iron sulfide contained in the carbonaceous slag is decomposed as shown in the following reaction formula 1, the generation of odor and black turbidity .

[Reaction Scheme 1]

_{FeS 2 + 2Ca (OH) 2} + 3.75O 2 → Fe (OH) 3 + 2SO 4 -2 + 2Ca +2 + 0.5H 2 O

The iron-based slag may be used as an aggregate after crushing the high-carbonaceous slag or the whisker-forming slag generated in the integrated steelworks. The shredded aggregate size was measured using KS F 2535: Hydraulic Particle Size Adjustment Blast Furnace Slag (HMS-25) and Particle Size Adjustment Steel Slag (MS- 40). The steel-making slag having a particle size of 50 mm or less can be used, but if it exceeds 50 mm, the compaction property of the slag is not perfect, so that there is a risk of sinking of the ground after completion of the embankment.

division Percentage of mass passing through sieve (%) Particle size range 50
Mm 40
Mm 30
Mm 25
Mm 20
Mm 13
Mm 5
Mm 2.
Mm 0.4
Mm 0.08
Mm HMS-25 - - 100 95
~ 100 - 60
~ 80 35
~ 60 25
~ 45 10
~ 25 3
~ 10 MS-40 100 95
~ 100 - - 60
~ 90 - 30
~ 65 20
~ 50 10
~ 30 2
~ 10

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 1]

The granulated slag having a maximum size of 25 mm was crushed to have a particle size range of HMS-25 shown in Table 1 to prepare an embankment. Then, compaction was carried out with a soil compaction test method (KS F 2312) Respectively. The optimum water content was 7.2% by weight and the maximum dry density was confirmed.

The Ca (OH) ₂ solution was used for the blast furnace slag, and the compaction was carried out in accordance with KS F 2312, and specimens for the measurement of CBR were prepared. The CBR test specimens were cured at a constant temperature of 20 ° C and a relative humidity of 95% for 28 days, and then subjected to a CBR (KS F 2320) test to measure the load-bearing strength.

In addition, to measure the expandability of the embankment after compaction, the cumulative expansion value measured at 80 ° C for 10 days after immersing the specimen in accordance with the method of measuring the swelling ratio of steel slag (KS F 2535) was defined as the expansion ratio of the specimen.

[Comparative Example 1]

CBR test was carried out in the same manner as in Example 1 except that only water was used in place of the Ca (OH) ₂ solution in the blast furnace slag, and the load strength and the expansion value were measured.

[Comparative Example 2]

The CBR test was carried out in the same manner as in Comparative Example 1, except that the composite furnace slab (70% by weight of converter steel making slag and 30% by weight of granulated slag) was used as the embankment, and the load strength and the expansion value Were measured.

As a result of the above test, the average value of CBR of Example 1 in which the Ca (OH) ₂ solution was sprayed into the blast furnace slag refractory material was measured to be 104%, and water was sprayed on the blast furnace slag refractory material The average value obtained by measuring the CBR of Comparative Example 1 five times was 87%. In addition, CBR of Comparative Example 2 in which water was sprinkled on the conventional composite furnace was measured five times, and the average value was 99%. From these results, it was found that the load strength of Ca (OH) ₂ solution was increased by spraying Ca (OH) ₂ solution on the embankment containing steel slag.

In addition, as a result of the water-swelling test, the expansion values of Example 1 and Comparative Example 1 were as low as 0.01% to 0.05%, while the Comparative Example 2 showed a large expansion value of 0.98%, and the embankment composed of the blast- Which is higher than that of the embankment containing water.

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 (6)

A method for treating an embankment with a steel slag for spraying a solution containing Ca (OH) ₂ , CaCO ₃ or a mixture thereof in an amount of 5 to 10 parts by weight per 100 parts by weight of an embankment containing aggregate slag as an aggregate.
delete The method of treating an embankment with a steel slag according to claim 1, wherein the granular slag is a blast furnace slag, a whitewashed slag, or a mixture thereof.
The method of claim 1, wherein the Ca (OH) _2, CaCO ₃ or solution is water, Ca (OH) _2, CaCO ₃ or mixtures thereof per 100ml mixtures thereof 0.01 g to 0.5 g dissolved in the slag.
delete The method according to claim 1, wherein the steel slag has a grain size of 50 mm or less.