KR100516188B1 - Calcium oxide solidifier composition comprising titanium gypsum - Google Patents

Abstract

The present invention can obtain a raw material saving effect by recycling the titanium gypsum which is a waste generated in the smelting process of titanium, and relates to a solidified fire extinguishing composition excellent in ground improvement and ordering effect. As a result of the uniaxial compressive strength and permeability test, the solidified material composition of the present invention had better ground improvement and ordering effect in sand, granite soil, and clay ground than conventional solidified materials and general portland cement. Therefore, it can be applied to a variety of ground, such as the lower ground of the riverbank embankment structure, it is possible to obtain an effect that can significantly reduce the amount of portland cement. In addition, by using the waste generated in the smelting process of titanium has the advantage of recycling the industrial by-products. In addition, the cost of the solidified fire according to the present invention is about 83% cheaper than the cost of portland cement, and it is economical because the low price can obtain the same strength and order effect as the existing solidified fire.

Description

Calcium oxide solidification composition containing titanium gypsum {CALCIUM OXIDE SOLIDIFIER COMPOSITION COMPRISING TITANIUM GYPSUM}

The present invention relates to a solidifying composition, and more particularly, to recycling the titanium gypsum, which is a waste generated in the process of smelting titanium, to obtain a raw material saving effect, and relates to a solidifying composition having excellent ground improvement and ordering effect.

Due to the recent completion of the West Coast Highway, the development of the West Coast is in full swing, and large scale industrial complex projects are being actively carried out. Such development is being carried out on the soft ground near the sea or on the coast. Since the soft ground has a high water content, the ground must be reinforced with ground modifiers or solidified fires. Therefore, the necessity of the ground improving material or solidified material is increasing, and there is an urgent need to develop a ground improving material having better characteristics or to introduce a new type of ground improving technology.

Solidifier is a substance that solidifies hydrous soft soil. It is added to soft soil and reacts with target soil in the soil to form a solid physico-chemical hardening body to strengthen the ground, and solidify harmful wastes and heavy metals contained in water. It is known to play a role of harming the back and changing the form into a difficult form.

Conventionally, cement or lime was used as such a solidified material. In addition, cement-based ground modifiers (cement-based solidifiers) including cement, gypsum, slag, coal ash, and alumina cements that enhance solidification performance have been developed and used since the 1970s. Is being developed. However, although cement and lime and cement-based solidifying materials improve the strength of soft ground, cement is expensive because it is manufactured by firing at high temperature, and in the case of lime, a huge amount is mined, causing severe natural damage. There is a problem of finite resources. In addition, the cement-based solidified material also has a problem that it is expensive because the cement occupies most of the main component. Therefore, there is an urgent need to reduce costs and to develop alternative solid fires for the saving of calcite resources and environmental protection.

The present inventors while researching to overcome the problems of using the existing solidified fire, it is possible to reduce the raw material cost by recycling the titanium gypsum, which is a waste generated during the smelting process to produce a solidified fire composition, the composition is uniaxial compressive strength The present invention was completed by confirming that the ground improvement effect was high and the order effect was also excellent.

The technical problem to be achieved by the present invention is to provide a solid fire material having a raw material cost reduction effect and excellent ground improvement effect and order effect in all soils.

In order to achieve the above object, the present invention, 40-50% by weight cement, blast furnace slag 30-40% by weight, fly ash 10-15% by weight, 5-10% by weight of titanium gypsum and 3-5% by weight of the active agent It provides a solidified composition consisting of.

Hereinafter, the present invention will be described in detail.

The solidified composition according to the present invention is characterized in that it comprises 40-50% by weight cement, blast furnace slag 30-40% by weight, fly ash 10-15% by weight, 5-10% by weight of titanium gypsum and 3-5% by weight of the active agent It is done.

In general, the process of solidification of the soft ground is a process of strength development in which the granules are initially bound by ettringite and the strength of the granules is enhanced by the lime-silicate hydration reaction and the additional pozzolanic reaction of the pozzolanic substance. Is done.

Cement causes hydration reactions with the pore water in the soil, which leads to the formation of ethrinzite, which forms crystallized needles that fill the gaps in the soil, lowering the water content in the soil, densifying solids, and ion exchange Toxic heavy metals and organics are fixed by overexpansion. Therefore, it is preferred that cement be included in the composition of the present invention for the production of ethrinzite, most preferably in the range of 40-50% by weight. When the content of cement in the above is less than 40% by weight, the production of ethrinzite is not made, when the content of more than 50% by weight is included in the content of the above range because the cost of the solidified material increases due to the use of excessive cement It is preferable. The cement is preferably portland cement, but is not limited thereto, and cement commonly used in the art may be used.

On the other hand, blast furnace slag and fly ash is added to the composition of the present invention for the hydration reaction and the pozzolanic reaction during the solidification process. The blast furnace slag and fly ash contain a large amount of pozzolanic reactants, silicon dioxide (SiO ₂ ) and aluminum oxide (Al ₂ O ₃ ), and sulfur trioxide (SO ₃ ) which effectively produces ethrinite in the hydration reaction. Since it also contains a large amount, it is possible to continuously promote the hydration reaction and pozzolanic reaction to maintain a stable strength of the ground. Therefore, it is preferable to be included in the composition of the present invention, blast furnace slag 30-40% by weight, fly ash is preferably added in an amount of 10-15% by weight for effective hydration reaction and pozzolanic reaction.

The composition of the present invention is characterized in that it contains titanium gypsum in addition to the cement, blast furnace slag, fly ash. Titanium gypsum is a waste generated in the process of smelting titanium, and when added to the solidification composition of the present invention, it is possible to reduce the overall cost of the finished solidification material and has a property of neutralizing strong alkali components, which is preferably included in the present invention. Do. Titanium gypsum is preferably added in an amount of 5-10% by weight. If it is added in an amount less than 5% by weight, the production of ethrinzite is lowered, and when it is added in excess of 10% by weight, the strength of the composition is weak. It is preferable to add in such a range because it loses. In addition, it is preferable to use titanium gypsum containing 2-3 wt% of titanium dioxide (TiO ₂ ) in the solidifying composition according to the present invention. The titanium dioxide has a property of promoting an electrical reaction.

On the other hand, the composition of the present invention is characterized in that it comprises an active agent for the strength enhancing effect. Preferably, the active agent is included in an amount of 3-5% by weight. If the content of the active agent is less than 3% by weight, the effect of enhancing the strength of the composition is insufficient. Become Because. As the activator, it is preferable to use a sodium-based activator, and more preferably, sodium sulfate (Na ₂ SO ₄ ).

As a result of the uniaxial compressive strength test of the solidified composition according to the present invention by manufacturing and curing specimens for compressive and flexural strength test of soil-cement (KS F standard: 2329), 120-130kg / cm ² in clay 20-25kg / cm ^{2 in the} soil and 70-80kg / cm ² in the granite soil.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited to the following examples.

Example 1 Preparation of Solidified Material

Ordinary sodium chloride was mixed with portland cement, titanium gypsum, blast furnace slag powder, fly ash and an activator to prepare a solidified material as shown in Table 1 below. The components of each material used for preparing the solidified material are shown in Table 2 below. As shown in Table 2, the content of titanium dioxide in the titanium gypsum used to prepare the solidified material of the present invention was 2.36%.

Common Portland Cement Titanium gypsum Blast Furnace Slag Powder Fly ash Sodium sulfate Total (% by weight) 40 10 32 15 3 100

Ingredient Portland Cement Blast Furnace Slag Powder Fly ash Titanium plaster SiO ₂ 22 34.2 50.2 4.15 Al ₂ O ₃ 6 13.5 21.6 0.94 Fe ₂ O ₃ 3 0.83 7.84 19.19 TiO ₃ - 1.05 0.71 2.36 CaO 63 41.1 10.09 21.1 MgO 2.5 5.8 2.43 0.94 Na ₂ O - 0.29 1.52 0.02 K ₂ O - 0.20 1.33 0.06 SO ₃ 2 0.73 - 28.9 lg-loss 1.5 2.3 4.28 22.34 Total (% by weight) 100.0 100.0 100.0 100.0

On the other hand, the risk of each mixed material of the solidified material according to the present invention was analyzed. The risk analysis of the solidified fire was measured by the presence or absence of heavy metals based on the waste process test, and the results are shown in Table 3 below. As a result of the dissolution test, it was confirmed that each component is a substance with less environmental impact within the legal standard value.

Ingredients Detection Component Fly ash Blast furnace slag Titanium plaster Cu 0.08 Not detected Not detected Pb Not detected Not detected Not detected CD Not detected Not detected Not detected Cr ⁶⁺ 0.03 Not detected Not detected As Not detected Not detected Not detected Hg Not detected Not detected Not detected CN Not detected Not detected Not detected TCE Not detected Not detected Not detected PCE Not detected Not detected Not detected Organic phosphorus Not detected Not detected Not detected

Example 2 Preparation of Test Specimen Sample

25 wt% of the solidified material prepared in Example 1 was added to sand, granite soil and clay to prepare specimen samples for performance test. Each sample was 5 cm in diameter and 10 cm in height, and molded at a curing temperature of 25 ° C. The molding method of the sample was molded by the method of manufacturing and curing specimens for compressive and flexural strength test of soil-cement in the laboratory of KS F 2329, and the uniaxial compressive strength test (KSF 2320) and the variable pitched pitch according to the following Test Examples 1 and 2 The test (KSF 2322) was performed.

Comparative Example 1 and Comparative Example 2

A specimen sample for performance comparison test was prepared in the same manner as in Example 2, except that 25 wt% of Portland cement was added to sand, granite, and clay (Comparative Example 1). In addition, by adding 25% by weight of the existing solidified material to the sand, granite and clay, respectively, to prepare a test specimen for the performance comparison test in the same manner as in Example 2 (Comparative Example 2).

Test Example 1 Uniaxial Compressive Strength Test

The uniaxial compressive strength test (KS F 2320) was performed on the samples prepared in Example 2 and Comparative Examples 1 and 2, and the results are shown in Table 4 and FIGS. 1A, 1B, and 1C.

Uniaxial compressive strength test result (kg / cm ² ) Experimental condition Rebirth (Sun) 7 days 14 days 28 days Sand ground Example 1 66.8 102.0 122.2 Comparative Example 1 69.2 102.9 115.2 Comparative Example 2 20.7 30.5 40.8 Granite soil Example 1 55.2 72.0 78.3 Comparative Example 1 49.2 60.1 82.4 Comparative Example 2 45.5 59.6 70.7 Clay ground Example 1 13.5 16.6 20.9 Comparative Example 1 9.2 10.8 14.0 Comparative Example 2 11.3 16.6 20.7

As shown in Table 4 and FIG. 1, in the case of the aged sand ground, the solidified material of the present invention and the solidified material of Comparative Example 1 showed similar values within an error range of 10%, but the solidified material of Comparative Example 2 was considerably low. Showed strength. That is, when the intensity of Comparative Example 1 was 100, the solidified material of the present invention exhibited almost the same strength as 96.6-106.0, but the solidified material of Comparative Example 2 exhibited a strength of 30% level at 29.9-35.4 (see FIG. 1A). ).

In addition, in the case of granite soil, the solidified materials of the present invention, Comparative Example 1 and Comparative Example 2 showed an equivalent degree of strength (see Fig. 1b).

In addition, in the case of clay ground, the solidified material of the present invention and the solidified material of Comparative Example 2 showed similar values within an error range of 10%, but the comparative example 1 showed a significantly low strength. That is, when the intensity of Comparative Example 1 is 100, the solidified material of the present invention is 147-153, Comparative Example 2 is 123-153 shows a 50% increase in strength (see Fig. 1c).

That is, as a result of the experiment, Comparative Example 1 shows a significant decrease in strength in clay, and shows good strength only in sandy and granite soils. On the other hand, it can be seen that the solidified fire according to the present invention exhibits high strength in all soil conditions such as sand, granite, clay, and the like.

Test Example 2 Permeability Test

A variable permeability test (KS F 2322) was performed on the samples prepared in Example 2 and Comparative Examples 1 and 2, and the results are shown in Table 5 and FIGS. 2A, 2B, and 2C.

Permeability Test Results (cm / sec) Experimental condition Rebirth (Sun) 7 14 28 Sand ground Example 1 1.0E-04 6.2E-05 4.7E-05 Comparative Example 1 1.5E-04 7.6E-05 6.6E-05 Comparative Example 2 3.4e-04 1.9E-04 1.4E-04 Granite Soil Example 1 1.5E-07 7.3E-08 6.1E-08 Comparative Example 1 2.2E-07 1.5E-07 9.8E-08 Comparative Example 2 1.6E-07 8.3E-08 7.5E-08 Clay ground Example 1 5.8E-08 3.6E-08 1.8E-08 Comparative Example 1 1.0E-07 8.6E-08 6.5E-08 Comparative Example 2 5.6E-08 3.9E-08 2.2E-08

As shown in Table 5 and FIG. 2, in the case of sand ground, the solidified material of Comparative Example 2 showed a low order effect, while the solidified material of Comparative Example 1 and the present invention showed a relatively high degree effect (FIG. 2a).

In addition, in the case of granite soil, the solidified materials of the present invention, Comparative Example 1 and Comparative Example 2 showed an equivalent degree of order effect (see Fig. 2b).

In addition, in the case of clay ground, the solidified material of Comparative Example 1 showed a low degree of effect, while the solidified material of the present invention and Comparative Example 2 showed a high degree of effect (see FIG. 2C).

That is, as a result of the experiment, Comparative Example 1 showed good order effect only in the sandy ground and granite soil, Comparative Example 2 only in clay ground and granite ground, whereas the solidified fire according to the present invention is all sand, granite, clay, etc. It can be confirmed that the high order effect is shown in the ground condition.

Test Example 3 Economic Analysis of Fire

When the solidified material of the present invention prepared in Example 1 and the solidified material price of Comparative Examples 1 and 2 were compared, the solidified material prepared in the present invention was about 83% cheaper than the solidified material of the Comparative Example.

In addition, as shown in Figure 3, the solidified material of the present invention is 78% (Figure 3a) price of the existing solidified material in the case of sand, 87% (Figure 3b) price of the existing solidified material in the case of granite soil, clay ground In this case, it could be confirmed that the same strength can be obtained at a price of 56% of the existing solidified material (FIG. 3C).

As described above, the solidified composition of the present invention showed superior ground improvement and ordering effects in sand, granite, and clay in comparison with existing solidified materials and general portland cement as a result of uniaxial compressive strength and permeability test. Therefore, it can be applied to a variety of ground, such as the lower ground of the riverbank embankment structure, it is possible to obtain an effect that can significantly reduce the amount of portland cement. In addition, by using the waste generated in the smelting process of titanium has the advantage of recycling the industrial by-products. In addition, the cost of the solidified fire according to the present invention is about 83% cheaper than the cost of portland cement, and it is economical because the low price can obtain the same strength and order effect as the existing solidified fire.

Figure 1a is a graph showing the uniaxial compressive strength in the sand ground of the solidified material (Example 1) and the conventional solidified material (Comparative Example 1, Comparative Example 2) according to the present invention.

Figure 1b is a graph showing the uniaxial compressive strength in the granite soil of solidified material (Example 1) and conventional solidified material (Comparative Example 1, Comparative Example 2) according to the present invention.

Figure 1c is a graph showing the uniaxial compressive strength in the clay ground of the solidified material (Example 1) and the conventional solidified material (Comparative Example 1, Comparative Example 2) according to the present invention.

Figure 2a is a graph showing the coefficient of permeability in the sand ground of the solidified material (Example 1) and the conventional solidified material (Comparative Example 1, Comparative Example 2) according to the present invention.

Figure 2b is a graph showing the permeability coefficient in the granite soil of the solidified material (Example 1) and the conventional solidified material (Comparative Example 1, Comparative Example 2) according to the present invention.

Figure 2c is a graph showing the coefficient of permeability in the clay ground of the solidified material (Example 1) and the conventional solidified material (Comparative Example 1, Comparative Example 2) according to the present invention.

Figure 3a is a graph showing the material ratio relationship to the uniaxial compressive strength in the sandy ground of the solidified material (Example 1) and the conventional solidified material (Comparative Example 1) according to the present invention.

Figure 3b is a graph showing the material ratio relationship to the uniaxial compressive strength in the granite soil of solidified material (Example 1) and conventional solidified material (Comparative Example 1) according to the present invention.

Figure 3c is a graph showing the material ratio relationship to the uniaxial compressive strength in the clay ground of the solidified material (Example 1) and the conventional solidified material (Comparative Example 1) according to the present invention.

Claims (5)

Solidified composition comprising 40-50% by weight of cement, 30-40% by weight of blast furnace slag, 10-15% by weight of fly ash, 5-10% by weight of titanium gypsum and 3-5% by weight of sodium-based activator. The method of claim 1, The titanium gypsum is characterized in that it contains 2-3% titanium dioxide Solidified composition. delete The method of claim 1, The active agent is characterized in that sodium sulfate Solidified composition. The method of claim 1, Soil-compression and bending strength by the laboratory specimen making method, and curing of the cement (KS F Spec: 2329) in the uniaxial compressive strength of a sandy soil 120-130kg / cm ^2, the clay 20-25kg / cm ^2, the screen Granite Soil Characterized in that 70-80kg / cm ² Solidified composition.