KR20230003785A - Fluidizing filler composition using circulating resources - Google Patents

Abstract

The present invention relates to a fluidizing filler composition using circulating resources. The fluidizing filler composition of the present invention is a lightweight, low strength and non-contract fluidizing filler composition comprising, as a binder, 15-1,000 parts by weight of blast furnace slag micro powder and 15-1,000 parts by weight of one kind of cement, based on 100 parts by weight of steelmaking process dust containing content of 30-50 wt% of Na_2O and 30-50 wt% of SO_3 generated during desulfurizing processes in a steel mill and as a lightweight aggregate, 5-5,000 parts by weight of any one or in a mixture of waste insulation materials selected from expanded perlite or expanded vermiculite and crushed to have a particle size of 10 mm or less. The binder and aggregate are replaced and used as circulating resources and serve as self-compacting and high fluidized filler, and quick hardening is possible after filling the same into an empty space as a back filler of a structure and pipes and filler for grounds, closed stone quarry, closed mine, and closed pipes, and weight reduction, re-excavation and volume stabilization are possible.

Description

Fluidizing filler composition using circulating resources {FLUIDIZING FILLER COMPOSITION USING CIRCULATING RESOURCES}

The present invention relates to a fluidized filler composition using circulating resources, and more particularly, as a binder, steel-making process dust having a Na ₂ O content of 30 to 50% by weight and a SO ₃ content of 30 to 50% by weight generated during the desulfurization process of a steelworks. For 100 parts by weight, it contains 15 to 1,000 parts by weight of blast furnace slag fine powder and 15 to 1,000 parts by weight of type 1 cement, and as a lightweight aggregate, any waste thermal insulation material selected from expanded perlite or expanded vermiculite is crushed to a particle size of 10 mm or less. By including 5 to 5,000 parts by weight in one or a mixture form, the binder and aggregate can be used as a circulating resource as an alternative, but can be used as a non-compacting, high-flow filling material, in particular, while the light weight effect is greatly expressed, the empty space is stably filled without cavitation It relates to a fluidized filler composition useful for structures and pipeline backfills, ground, waste mines, abandoned mines and closed pipe fills.

Recently, in order to prevent ground sinking due to the destruction of old underground closed pipes that are difficult to demolish, a method of filling lightweight foamed concrete has been widely applied. It is a high-level processing method, and secondary settlement occurs due to bubble bursting, and durability is weak, resulting in a short lifespan.

In addition, in order to prevent subsidence and collapse by backfilling the rear part of the retaining wall with embankment material during the construction of the retaining wall, it is a lightweight embankment material that can prevent lateral flow by reducing the earth pressure and reducing the load on the soft ground to prevent subsidence. A method of pouring by mixing polystyrene (aka styrofoam) granules with cement and field soil has been mainly used.

However, it has a problem that can cause environmental pollution by future expandable polystyrene grains.

Therefore, it is necessary to develop a cost-saving lightweight-low-strength-non-shrinkage fluidized filling material with excellent filling performance and durability and environmental stability.

In general, excavation work is carried out to bury transmission pipelines, gas pipelines, water supply pipelines, etc. in cities. The site soil generated in the construction is treated with soil, and high-quality sand is purchased to backfill the back surface of the pipe laying. there is. However, this has problems in that the construction cost increases, such as the cost of transporting and discarding the site-generated soil to the sandy site and the cost of purchasing high-quality sand. There are many problems, such as the inevitability of settlement after construction, because it does not sufficiently penetrate into the narrow space on the rear surface of the laid pipe.

In addition, although a method such as a water compaction method is used to improve such inappropriate compaction, there are many difficulties in construction such as water flowing into a specific section due to a gradient of excavation work.

In order to solve these problems, a plan to utilize CLSM (Controlled Low Strength Materials) composed of field soil, cement, fly ash, water, admixture, etc. It has the disadvantage of long curing period, so it is not used in actual construction.

Recently, by improving the problems of the existing backfilling method, fast-setting solidification materials in which general cement is mixed with fast-setting cement and slag fine powder have been proposed.

For example, in Patent Document 1 and Patent Document 2, 15 to 30 parts by weight of calcium ferro aluminate (CFA) or calcium sulfo aluminate (CSA)-based minerals are added to general cement and slag fine powder, respectively. and a technique of mixing 25 to 45 parts by weight has been proposed.

However, Calcium Ferro Aluminate (CFA) or Calcium Sulpho Aluminate (CSA) is a special cement that is not produced in Korea but mainly imported from China and Japan. It is an extremely expensive product that exceeds 10,000 won and is about 10 times the price of general cement, so it is an irrational method that requires a lot of cost.

The above prior art is intended to increase the strength and durability of the soil by hydrating the inorganic solidifying material and soil mixed with cement, blast furnace slag powder, CSA, CFA, lime, etc. and forming ettringite, but the natural This reaction is inhibited by organic acids formed by the decomposition of organic matter in soil.

Therefore, in order to have a predetermined strength and durability, more than a certain amount of cement is required, but cement is a strong alkali substance and has a bad effect of accelerating basicity of the soil by increasing the alkalinity of the solidified soil.

Accordingly, the inventors of the present invention have made efforts to improve the conventional problems, and as a result, the binder, aggregate, and water are generated at the steelmaking process dust, blast furnace slag powder, and the replacement of the thermal insulation insulation material in the petrochemical complex piping, which are generated in steel mills as the binder and aggregate. Provides a fluidized filler composition capable of compaction-free filling using waste heat-insulating insulation materials, and hardened after filling the composition into large voids such as structures and pipeline backfills, ground, waste mines, abandoned mines and closed pipe fills The present invention was completed by confirming the physical properties of lightweight-low-strength-non-shrinkage performance.

Republic of Korea Patent No. 10-0772637 (2007.11.02 announcement) Republic of Korea Patent No. 10-0772638 (2007.11.02 announcement)

The present invention is to provide a fluidized filler composition using circulating resources.

In order to solve the above technical problem, the present invention, as a binder, the Na ₂ O content generated during the steelworks desulfurization process is 30 to 50 wt% and the SO ₃ content is 30 to 50 wt% Regarding 100 parts by weight of dust in the steelmaking process, It contains 15 to 1,000 parts by weight of blast furnace slag fine powder and 15 to 1,000 parts by weight of type 1 cement, and 5 to 5,000 parts by weight of any one or a mixture of two or more pulverized waste thermal insulation materials selected from expanded perlite or expanded vermiculite as a lightweight aggregate to a particle size of 10 mm or less. It provides a fluidized filler composition, including a part.

In the above, the binder may further include 5 to 500 parts by weight of expandable fly ash having a CaO component of 15% by weight or more with respect to 100 parts by weight of the steelmaking process dust, and the fly ash is composed of coal, solid fuel, organic sludge and waste vinyl It is emitted by using any one or a mixture of two or more selected from the group as fuel.

In addition, in order to improve the light weight of the binder, 0.1 to 100 parts by weight of any one selected from animal foaming agents, vegetable foaming agents, hydrogen peroxide, and aluminum powder, or a foaming agent of a mixture of two or more, based on 100 parts by weight of the steelmaking process dust. More may be included.

In the fluidized filler composition of the present invention, the lightweight aggregate is discharged without a separate fiber separation process when the waste thermal insulation material is pulverized, and the absolute dry density is in the range of 0.15 to 1.0 g/cm ³ is used.

According to the fluidized filler composition of the present invention, it is possible to fill without compaction, and to enable load reduction, re ^- excavation, and volume stability. Light weight and performance of less than 5% bleeding rate are expressed.

Therefore, since the fluidized filler composition of the present invention can be rapidly cured after being filled in empty spaces, it is useful for backfilling of structures and pipelines, ground, abandoned mines, abandoned mines, and closed pipes.

Binders and aggregates included in the fluidized filler composition of the present invention use steelmaking process dust, blast furnace slag fine powder, and waste thermal insulation materials generated at the site of replacing thermal insulation insulation materials in petrochemical complexes generated in steel mills, and by damaging natural resources. It can replace cement and natural aggregates that must be obtained.

In addition, the fluidized filler composition of the present invention has the advantage that it can be used by pouring only water in the field after mixing in advance at the factory so as to facilitate quality control at the site.

Hereinafter, the present invention will be described in detail.

The fluidized filler composition of the present invention is composed of a binder, an aggregate, and water, and 100 parts by weight of steelmaking process dust having a Na ₂ O content of 30 to 50% by weight and a SO ₃ content of 30 to 50% by weight generated during the steelworks desulfurization process as a binder. 15 to 1,000 parts by weight of blast furnace slag fine powder and 15 to 1,000 parts by weight of type 1 cement, and any one or a mixture of two or more adjusted by grinding waste thermal insulation materials selected from expanded perlite or expanded vermiculite as lightweight aggregates to 10 mm or less It contains 5 to 5,000 parts by weight, and provides a fluidized filler composition that expresses light-weight-low-strength-non-shrinkage performance using circulating resources.

Hereinafter, the characteristics of each composition of the fluidized filler composition using the circulating resource of the present invention will be described.

1) binder

In the fluidized filler composition of the present invention, the binder includes iron-making process dust including 30 to 50% by weight of Na ₂ O content and 30 to 50% by weight of SO ₃ content generated during the steelworks desulfurization process.

In the steelmaking process, sintered ore is produced before iron ore is put into the blast furnace at the _{steelworks .} ) will be put in. Sodium bicarbonate undergoes a desulfurization reaction and finally, the main component is sodium sulfate (Na ₂ SO ₄ ), which is discharged in the form of dust.

Scheme 1

The steelmaking process dust cannot be recycled in the steelworks due to the lack of useful components such as Fe and Ca, and there is no appropriate treatment method other than landfill treatment.

However, due to the influence of the Framework Act on Resource Circulation, which has been enforced since 2018, disposal charges are incurred for landfill treatment, and consigned landfill treatment costs are also rapidly increasing. .

However, in the case of sodium sulfate (Na ₂ SO ₄ ), which is the dust in the steelmaking process, when reacting with water, it dissolves into Na ⁺ and SO ₄ ^2- , which can rapidly accelerate the hydration reaction of cement and induces a complex stimulation of alkali and sulfate, so it has latent hydraulic properties. By stimulating the blast furnace slag fine powder, which is a material, the hydration reaction can be rapidly promoted at an early stage.

In addition, since it is easily soluble in water and occurs in the form of a fine powder, it has the advantage of being immediately usable without additional processing such as crushing. Therefore, sodium bicarbonate desulfurization dust generated as a by-product during the steelmaking process has the advantage of being utilized as a hydration promoting action of cement and a reaction stimulator of blast furnace slag.

The present invention, as a binder, may further include 5 to 500 parts by weight of expandable fly ash having a CaO component of 15% by weight or more based on 100 parts by weight of the steelmaking process dust.

The fly ash is discharged using any one or a mixture of two or more selected from the group consisting of coal, solid fuel (SRF, BIO-SRF), organic sludge, and waste vinyl as fuel.

When the fly ash reacts with water, it plays a role of adsorbing an excess amount of water present in the space to be filled and increasing viscosity, along with volume expansion, thereby suppressing material separation.

At this time, with respect to 100 parts by weight of dust in the steelmaking process, if the fly ash is contained in less than 5 parts by weight, the effect is not exhibited, whereas if it exceeds 500 parts by weight, the relatively fluidity rapidly decreases and the expansion becomes excessive. can

In addition, the fluidized filler composition of the present invention may further include 0.1 to 100 parts by weight of a pore former with respect to 100 parts by weight of the iron-making process dust in order to enhance the lightweight effect.

The pore forming agent is preferably any one or a mixture of two or more selected from the group consisting of animal foaming agents, vegetable foaming agents, hydrogen peroxide, and aluminum powder. At this time, if the amount of the bubble forming agent is less than 0.1 parts by weight, the effect is ineffective, and if it is greater than 100 parts by weight, it is more advantageous to secure light weight, but the strength rapidly decreases.

In the fluidized filler composition of the present invention, the fine powder of blast furnace slag included as a binder is a by-product obtained by quenching slag in a high-temperature molten state, which is generated as a by-product in the steel-making blast furnace process, with water. When the blast furnace slag powder comes into contact with water, it forms an amorphous film and does not undergo a hydration reaction by itself, so the blast furnace slag powder is called latent hydraulic material. In order to exhibit latent hydraulic properties, the amorphous film must be destroyed.

The blast furnace slag fine powder is inspected to have a 0.045 mm (45 μm) sieve residue of less than 10%, or pulverized and classified, and water quenched blast furnace slag obtained by quenching the slag with water is pulverized and used.

Since the blast furnace slag fine powder consists of less than 10% of the 0.045 mm (45 μm) sieve residue, there is an advantage in that latent hydraulic properties can be exhibited by improving the activity of the particles.

When water is added to the normal blast furnace slag fine powder, an amorphous film is formed on the surface, and elution of Ca ²⁺ , Al ³⁺ , etc. from the inside does not occur. However, when water is introduced after mixing the steelmaking process dust, it does not absorb water rapidly and is quickly dissolved in water, divided into Na ⁺ and SO ₄ ^2- and separated into ionic states, so that the SO ₄ ^2- component of the blast furnace slag fine powder By destroying the amorphous film, elution of Ca ²⁺ and Al ³⁺ is facilitated, and elution ions accelerate hardening by generating CaO-SiO ₂ -H ₂ O-based hydrates, etc., and excess sulfur oxides are needle-shaped. By generating an ettringite hydration product (3CaO·Al ₂ O ₃ ·3CaSO ₄ ·32H ₂ O), which is an expansive mineral having a structure, the internal structure of the hydrated body is densified to improve the compressive strength and expandability of the hardened body. Can be induced.

It is preferable that 15 to 1,000 parts by weight of the blast furnace slag fine powder is mixed with respect to 100 parts by weight of the iron-making process dust. At this time, when the content of the fine blast furnace slag powder is less than 15 parts by weight, the reaction of the fine blast furnace slag powder can be achieved by almost 100%, but the amount of the stimulant is relatively excessive compared to the fine powder of blast furnace slag, so that a large amount of unreacted steelmaking process dust exists to express strength this becomes difficult On the other hand, when the blast furnace slag is mixed in an amount exceeding 1,000 parts by weight, the stimulating effect by the process dust is weak, so the initial strength is rapidly lowered, and an excess amount of slag that does not initiate a hydration reaction exists, which is disadvantageous in terms of economy.

In addition, cement included as a binder in the fluidized filler composition of the present invention can be used as long as it is generally commercially available type 1 cement, fly ash cement, blast furnace slag cement, early strong cement, semi early strong cement.

Cement is preferably 15 to 1,000 parts by weight of type 1 cement based on 100 parts by weight of iron manufacturing process dust. At this time, if cement is included in less than 15 parts by weight, it is difficult to develop initial strength, and if it exceeds 1,000 parts by weight, strength is excessively expressed, making future re-excavation difficult.

2) lightweight aggregate

The lightweight aggregate included in the fluidized filler composition of the present invention is preferably adjusted to a particle size of 10 mm or less, more preferably 0.01 to 10 mm by pulverizing waste thermal insulation materials containing 50% or more of expanded perlite or expanded vermiculite.

Expanded perlite or expanded vermiculite-based insulation materials are widely used to heat and insulate plant pipes in petrochemical industrial complexes, etc., where high temperatures must be maintained, resulting in a large amount of waste insulation materials during pipe replacement construction.

Currently, the main component of the waste thermal insulation material is expanded perlite or expanded vermiculite, sodium silicate is used as a binding material and organic short fibers are used as a reinforcing material, but it is difficult to separate them during disposal. However, since it has a very low density and occupies a large volume, it is expensive to landfill.

The waste thermal insulation lightweight aggregate forms a large number of pores, so the average dry density is about 0.15 to 1.0 g / cm 3, more preferably 0.2 to 0.4 / cm 3, which is very low, and can be very effective in reducing earth pressure by reducing load. .

In addition, the lightweight aggregate is discharged without a separate fiber separation process when pulverizing the waste thermal insulation material, and if it is simply pulverized without a separate separation process and used as the fluidized filler of the present invention, the reinforcing fibers contained in the waste thermal insulation material increase tensile force and bending strength It can play a role in increasing the amount of aggregate, and has the effect of suppressing material separation when mixed with water due to the coarsely ground aggregate surface and fibers.

With respect to 100 parts by weight of the iron-making process dust, it is preferable that the lightweight aggregate is included in 5 to 5,000 parts by weight. At this time, if it is less than 5 weight, it is not possible to secure light weight, and if it is more than 5,000 parts by weight, material separation occurs severely when mixed with water, and it is difficult to express a predetermined strength.

The above fluidized filler composition using circulating resources of the present invention is a binder and aggregate, which can be filled without compaction by using steelmaking process dust, blast furnace slag fine powder, and waste thermal insulation materials generated at the site of replacing thermal insulation insulation materials in petrochemical complexes. It is possible to reduce load, re-excavation, and secure volume stability. 28 days of age, low strength of compressive strength of 0.3 to 5 MPa, unit volume weight of 500 to 1,500 kg/m ³ , light weight and bleeding rate of 5% or less. .

Hereinafter, the present invention will be described in more detail through examples.

These examples are intended to explain the present invention in more detail, and the scope of the present invention is not limited to these examples.

<Comparative example>

Based on 100 parts by weight of Type 1 Portland cement as a binder, 1,000 parts by weight of viscous soil (unit volume weight 1.72 ton/m ³ ) generated on site as an aggregate, 20 parts by weight of Styrofoam grains ground to 10 mm or less, and 150 parts by weight of water homogeneously After mixing, a slump flow test was conducted using the prepared sample (Type 1 Portland cement + field soil + Styrofoam pellets), and after curing by pouring into a cylindrical mold with a diameter of 10 cm and a height of 20 cm, unit volume weight and material age Star uniaxial compressive strength was measured.

<Example 1>

Based on 100 parts by weight of the binder (30% by weight of dust from the steelmaking process, 40% by weight of blast furnace slag powder, 30% by weight of type 1 cement), 200% by weight of pulverized waste thermal insulation material (expanded perlite) pulverized to 10 mm or less as a lightweight aggregate After homogeneously mixing 200 parts by weight of water and 200 parts by weight of water, a slump flow test was conducted using the prepared sample. After curing by pouring into a cylindrical mold with a diameter of 10 cm and a height of 20 cm, measured.

<Example 2>

Relative to 100 parts by weight of the binder (20% by weight of dust from the steelmaking process, 40% by weight of blast furnace slag powder, 30% by weight of type 1 cement, 10% by weight of expandable fly ash), use 10 mm or less of waste thermal insulation material (expanded perlite) as a lightweight aggregate. After homogeneously mixing 200 parts by weight of pulverized material and 200 parts by weight of water, a slump flow test was conducted using the prepared sample, and after being poured into a cylindrical mold with a diameter of 10 cm and a height of 20 cm and cured, unit volume weight and uniaxial compressive strength by age were measured.

<Example 3>

With respect to 100 parts by weight of the binding material (29.5% by weight of dust in the steelmaking process, 40% by weight of blast furnace slag powder, 30% by weight of type 1 cement, 0.5% by weight of aluminum powder), the waste heat-insulating material (expanded perlite) as a lightweight aggregate is reduced to 10 mm or less. After homogeneously mixing 200 parts by weight of pulverized water and 200 parts by weight of water, a slump flow test was conducted using the prepared sample. Uniaxial compressive strength was measured.

<Experimental Example 1> Performance test of fluidized filler

As shown in Table 1 below, the slump test was conducted according to the slump test method for concrete (KS F 2402) and the compressive strength test was performed according to the test method for compressive strength of concrete (KS F 2405), and the unit volume weight based on the 28-day curing agent was measured, and the volume change was visually inspected. The results are shown in Table 2 .

(1) Slump flow test results

As a result of measuring the slump flow for the cured bodies prepared in Comparative Examples and Examples 1 to 3, in the case of Comparative Examples and Examples 1 to 3, all of them were expressed at 60 cm or more, showing satisfactory results as a non-compacting high flow filling material. .

In particular, when the expandable fly ash was incorporated in Example 2, the slump flow tended to decrease slightly, which is interpreted as the fact that the expandable fly ash instantly absorbs a large amount of moisture.

(2) Unit volume weight of hardened body

As a result of measuring the unit volume weight of the cured product on the 28th for the cured product prepared in Comparative Example and Examples 1 to 3, in the case of the comparative example, it was 1.32 ton/m ³ , and due to the incorporation of Styrofoam grains, the weight of fluidized soil using general field sand was 1.6 Compared to ∼1.8 ton/m ³ , the unit volume weight decreased, but the unit volume weight was over 1.0 ton/m ³ , so there was no significant effect on the load reduction.

However, it was confirmed that the cured bodies prepared in Examples 1 to 3 had a unit volume weight of 1.0 ton/m ³ or less, which had a very large effect on reducing the load. This result is because the pulverized waste heat insulation insulation material was used as a lightweight aggregate, and it was confirmed that the lightweight effect was more pronounced when expandable fly ash or aluminum powder was mixed.

From the above, the cured bodies prepared in Examples 1 to 3 were confirmed to have a unit volume weight of 500 to 1,500 kg/m ³ and light weight.

(3) Uniaxial compressive strength test results

As a result of testing the uniaxial compressive strength of the cured bodies prepared in Comparative Example and Examples 1 to 3, the comparative example could not measure the strength at the age of 3 days, but the test specimens prepared in Examples 1 to 3 at the age of 3 days It was confirmed that the strength expression was possible and that the overall strength was expressed about twice as compared to the comparative example. From the above, the cured bodies prepared in Examples 1 to 3 support the development of low strength of 0.3 to 5 MPa in compressive strength at age 28 days.

(4) Volumetric contraction

As a result of visually observing the volumetric shrinkage of the cured products prepared in Comparative Example and Examples 1 to 3, the comparative example confirmed a volumetric shrinkage of about 10% or more, whereas the test body prepared in Examples 1 to 3 had volumetric shrinkage. This did not occur at all, and in Examples 2 and 3 incorporating expandable fly ash or aluminum powder, the volume slightly expanded by more than 1%, and it was judged that the empty space could be stably filled without cavitation.

Although the present invention has been described in detail only with respect to the specific embodiments described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention, and it is natural that such changes and modifications fall within the scope of the appended claims.

Claims (5)

As a binder, 15 to 1,000 parts by weight of blast furnace slag powder and 1-class cement are used for 100 parts by weight of iron-making process dust having 30 to 50% by weight of Na ₂ O and 30 to 50% by weight of SO ₃ generated during the desulfurization process of steelworks. 15 to 1,000 parts by weight,
A fluidized filler composition containing 5 to 5,000 parts by weight of any one or mixture of waste thermal insulation materials selected from expanded perlite or expanded vermiculite as a lightweight aggregate pulverized to a particle diameter of 10 mm or less. The fluidized filler composition according to claim 1, wherein, as the binder, 5 to 500 parts by weight of expandable fly ash having a CaO content of 15% by weight or more is further included based on 100 parts by weight of iron-making dust. The fluidized filler composition according to claim 2, wherein the fly ash is discharged using any one or a mixture of two or more selected from the group consisting of coal, solid fuel, organic sludge and waste vinyl as fuel. The method of claim 1, wherein, as the binder, 0.1 to 100 parts by weight of any one or a mixture of two or more foaming agents selected from the group consisting of animal foaming agents, vegetable foaming agents, hydrogen peroxide and aluminum powder, based on 100 parts by weight of steelmaking process dust A fluidized filler composition, characterized in that it further contains additional. The fluidized filler composition according to claim 1, wherein the lightweight aggregate has an absolute dry density in the range of 0.15 to 1.0 g/cm ³ .