JPH08165467A - Soil-hardening agent - Google Patents

Abstract

PURPOSE: To obtain a soil-hardening agent for stably hardening organic soil, capable of reaction similar to that for an inorganic object and also capable of sealing in the offensive odor and various toxic substances existing in the object and preventing them from leaching out again, having high-early- strengthening ability and rapid in reaction. CONSTITUTION: This soil-hardening agent stands incorporated, as aggregation- active ingredient, with at least a composition comprising 20-0wt.% of silicon oxide, 10-30wt.% of aluminum oxide, 10-50wt.% of calcium oxide, 5-15wt.% of sodium aluminate, 0.5-5wt.% of magnesium oxide and 0.01-10wt.% of SOx .

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to a soil solidifying agent. More specifically, the present invention relates to a soil solidifying agent useful in the solidification of organic soil and the containment of harmful substances, substances giving off a bad odor, etc. in various fields such as construction, civil engineering and agriculture.

[0002]

2. Description of the Related Art In the fields of civil engineering and construction, cement and cement-based solidifying agents have been usually used for adjusting the strength of soil and constructing artificial ground. However, in the case of these conventional cements and cement-based solidifying agents, the chemical reaction is hindered by the presence of the organic matter contained in the object to be treated, and an effective solidification reaction cannot be extracted with respect to the organic sludge and the like, and as a result, Rapid treatment of organic sludge has been hindered. In addition, in the case of organic sludge such as sludge, a malodor is generated due to the components dissolved in the water of the sludge, but with conventional cement and cement solidifying agents, it is input to such malodor sources. There is also a problem in that a strange odor is further added to the original bad odor by doing so. Furthermore, conventional cement and cement-based solidifying agents are also used at sites where it is judged that their use is not desirable, so use them while being aware of the environmental conservation problem that the pH value rises abnormally. There is a background that it has been done.

The present invention has been made in view of the above-mentioned circumstances, and replaces conventional cements and cement-based solidifying agents with excellent solidifying performance, such as organic soil, harmful substances, and substances giving off a bad odor. The purpose is to provide a new soil solidifying agent that can be contained and has good environmental protection.

[0004]

In order to solve the above-mentioned problems, the present invention has at least a weight percentage of 20% to 60% of silicon oxide and 10% to 30% of aluminum oxide as an aggregating active ingredient. , Calcium oxide 10%
.About.50%, sodium aluminate 5% to 15%, magnesium oxide 0.5% to 5%, and sulfur oxide 0.0.
There is provided a soil solidifying agent comprising a composition of 1% to 10%.

[0005]

The unique composition as described above improves the solidification performance, and is characterized in that the target soil is not distinguished between organic matter and inorganic matter. More specifically, the soil solidifying agent of the present invention, as a mechanism of the solidification reaction itself, is different from the cement system which has taken in water only by the conventional chemical reaction, by the physical water absorption action along with the chemical hydration reaction, the moisture content is increased. It realizes water and immobilization of organic substances and enables rapid solidification and solidification of soil solids. Further, this physical water absorption action does not distinguish between the inorganic substance and the organic substance of the target object, so that the initial curing reaction is accelerated.

The soil solidifying agent of the present invention contains silicon oxide, aluminum oxide, calcium oxide, sodium aluminate, magnesium oxide and sulfur oxide. The highly reactive silica and alumina components gel due to the sum reaction, and the coexistence with calcium oxide (quick lime) causes the entryin gite (3CaO · Al ₂ O ₃ ·.
3CaSO ₄ · 32H ₂ O) to form needle crystals. Ettringite, as shown in its chemical formula by 32H ₂ O, consumes large amounts of water in the hydration reaction itself and is capable of addressing large amounts of organics in the hydrate produced by the reaction.

As a result, the soil solidifying agent of the present invention fixes a large amount of water as crystals inside the porous structure, and at the same time promotes adsorption and fixation of fine particles and harmful components, without causing bleeding (floating water generation phenomenon). Condensation progresses, and in addition to containing harmful heavy metals, it also exhibits a deodorizing effect. Also, sodium aluminate, magnesium oxide,
With respect to sulfur oxide, aggregation and surface-active ion components are generated by the hydration reaction, and they are adsorbed on the surface of fine minerals in cohesive soil together with aluminum and calcium ions to neutralize them electrically and agglomerate and consolidate particles. Works to In addition to the quicklime ion reaction, it also promotes a borazon reaction with a clay mineral and ion exchange. In addition, it is also characterized by neutralizing excess aluminum and calcium, and further forming another entwinite by the reaction of the clay mineral and sulfur.

It is assumed that the soil solidifying agent of the present invention has three solidification reaction processes, namely an initial reaction, a medium-term reaction, and a long-term reaction. First, in the initial reaction, entangite is produced. It is produced by the coexistence of alumina, silica, sulfur and calcium. This entangingite produced by the hydration reaction of the solidifying agent has a weight of 40%.
It is a hydrate having 50% of water of crystallization, which acts to reduce the water content of soil. The hydration reaction is warmer than quick lime, but at the time when the hydration reaction proceeds, the action of fixing water is comparable to that of quick lime.

[0009] Enthinite is a heart-shaped crystal that forms crosslinks between soil particles to reduce the water content ratio and exert an assimilation strength. Since the reaction proceeds even in the presence of organic substances such as lignin, which is a solidification inhibitor of cement, it is possible to solidify in soil with a lot of organic substances. Next, the medium-term reaction is due to the formation of calcium silicate, and it is considered that reinforcement of cross-linking of the entangite by hydrated calcium silicate and improvement of solidification strength are aimed at. Similar to Portland cement, calcium silicate contains arit and perit, and a hydrate reaction of them produces calcium hydrate. This hydrate can reinforce the cross-linking of entangite and further improve the solidifying strength.

Further, in the long-term reaction process, the clay particles can be electrically neutralized by ion exchange by the pozzolanic reaction, the water molecules can be converted into free water and made hydrophobic, and the particles can be attracted to each other to achieve aggregation. Since the hydration reaction produces slaked lime similar to quicklime, it promotes the pozzolanic reaction of the clay mineral, ion exchange action, and unlike the case of quicklime, alumina in the clay mineral reacts with the sulfur and sodium to form water molecules The poles are electrically neutralized, the charge is lost, the hydrophilic groups in the sludge are destroyed, and the particles agglomerate. In addition, the reaction of sulfur produces another entryonite. The ions produced by these hydration reactions make the clay particles electrically charge-hydrophobicize the soil into aggregate particles, bind highly reactive silica and alumina, and form calcium silicate and calcium aluminate hydrate to form soil. It is considered that the particles are solidified. These reactions are called pozzolanic reactions, which generally occur with a long age and do not have the initial solidification strength. By incorporating such a mechanism of long-term strength, it becomes possible to adapt to the surrounding soil over time, to avoid the situation of artificial solidification, and to change to the most natural ground strength.

Further, in the present invention, by absorbing water into the porous structure, the odor in the sludge caused by the component dissolved in the water of the sludge is reduced in a short time by water absorption solidification, and almost no odor is generated at the solidification completion stage. It also has the property of changing to something that does not exist. In addition, ettringite also has a function of taking in harmful substances such as precious metals existing in an ionic state by a physical water absorption action, and further, the formation of this ettringite also has a coating action of preventing re-elution of the substance taken in. .

From the above, the soil solidifying agent of the present invention can be effectively applied to a site requiring rapid solidification or a site containing a large amount of organic matter. In addition, when there is a harmful substance or a substance that emits a foul odor in the target area or the target soil, it is possible to apply to containment of those substances or treatment of the target substance. Furthermore, by adjusting the amount used, the hydraulic conductivity of the solidified ground can be maintained, and since the pH value of the material is low, greening of the application site after solidification is expected.

Of course, the same effect can be obtained even with respect to the inorganic target soil to which the conventional solidifying agent can be applied, with a smaller amount of use than the conventional solidifying agent. As for the soil solidifying agent of the present invention which is capable of the above-described excellent action, silicon oxide is 20 to 60 wt%, more preferably 20 to 5 wt%.
0 wt%, aluminum oxide 10-30 wt%, more preferably 10-20 wy%, calcium oxide 10
˜50 wt%, more preferably 20 to 50 wt%, sodium aluminate 5 to 15 wt%, more preferably 5 to 10 wt%, magnesium oxide 0.5 to 5 wt%.
% And sulfur oxide are blended in the range of 0.01 to 10 wt%, but these components may be used alone or in combination as a mixture, or fly ash containing a part of these components. Alternatively, another inorganic substance or the like may be blended and used.

To explain the present invention in more detail,
Examples will be described below. Of course, the present invention is not limited to these embodiments.

[0015]

EXAMPLES The soil solidifying agent of the present invention was actually applied to organic sludge. The composition of the solidifying agent was such that the composition shown in Table 1 was obtained.

[0016]

[Table 1]

200 g of riverbed volume sludge which is organic sludge
Was collected and solidified using the soil solidifying agent of the present invention. For comparison, the same amount of sludge was solidified with a conventional commercially available cement-based solidifying agent. The rate of solidification is
In many experiments, 3-4 compared to conventional ones
It has twice the fast-curing property, and the strength of the obtained solidified body is equal to or higher than that of the conventional one (for example, 7 kgf in uniaxial compression strength).
/ Cm ² or more).

Moreover, in the case of the present invention, the malodor was completely eliminated, but in the conventional one, it was confirmed that an unpleasant odor was generated, which was not preferable.

[0019]

Industrial Applicability As described in detail above, the soil solidifying agent of the present invention has a fast-acting property and a rapid reaction, and enables the same reaction as that of an inorganic object in solidifying and stabilizing organic soil. . Further, it is possible to prevent the re-elution by containing the bad odor and various harmful substances contained in the object.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technology display location B09C 1/02 1/08 C02F 11/14 C C09K 17/02 P 17/08 P 17/12 P // C09K 103: 00 B09B 3/00 304 K

Claims (1)

[Claims] 1. A coagulation active component having a weight percentage of at least 20% to 60% silicon oxide, 10% to 30% aluminum oxide, and 10% to 50% calcium oxide.
, Sodium aluminate 5% to 15%, magnesium oxide 0.5% to 5%, and sulfur oxide 0.01% to 1
A soil solidifying agent comprising a composition of 0%.