JP2003049165A - Method for solidification or fixing of mud with inorganic material and product produced by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems of conventional methods achieving a certain success in the solidification of a soft ground and sludge comprising the difficulty in achieving economical solidification or fixation of the soft ground of a vast shore holding sludge deposited to a thickness of ten odd meters and the impossibility of the recycling of the sludge to produce a product having a strength comparable or superior to conventional concrete product. SOLUTION: Mud containing calcium ion is compounded with 1-20 wt.% volcanic ash having particle diameter of <=0.06 mm (in terms of solid component based on the total material) and 0.02-1 wt.% specific powdery Kira (levigation residue of silica sand, etc.), composed of silica sand sufficient for forming an aqueous colloidal solution and optionally silica sand and cement are added to the mixture to solidify the mud. The invention further provides the solidified product to solve the problems.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for solidifying or fixing a mud body using an inorganic material and its product.

[0002]

2. Description of the Related Art Needless to say, the inorganic hardening material most commonly used in civil engineering and construction is concrete whose main component is Portland cement, which allows a wide variety of structures to be widely spread. It is well known that it has been constructed.

[0003] When such a Portland cement that does not harden or cannot be dealt with is hardened, for example, a water glass-based solidifying material or a non-Portland cement or a chemical binder using magnesia, alumina or the like is used. As a result, some results have been achieved in the solidification of some soft ground and sludge.

[0004]

However, in such a conventional technique, there are still many sites where it is extremely difficult to deal with it realistically. For example, when solidifying or fixing the soft ground of a vast beach where sludge has accumulated more than a dozen meters, first of all, there is no hardening material that permanently cures sludge at low cost, let alone dredging sludge on site. It is almost impossible to harden it and refill it again, and even if the sludge is covered with ordinary earth and sand or concrete, the strength is insufficient and at the same time, organic substances and foul odors ooze out. There are drawbacks.

Further, fine aggregates used for concrete and having a particle size of 0.06 mm or less are not generally used because they inhibit hardening and do not provide strength, and this is also discarded as a troublesome material. The current situation is that I am in trouble.

The present invention solves the above problems and prevents the pollution of the environment and environmental protection by practically solidifying or fixing a mud body made of an inorganic material to a hard-to-solidify material or soft ground which has been considered to be extremely difficult. , And to broadly contribute to improving the physical properties of cured products.

[0007]

The inventor of the present invention has already succeeded in producing concrete having high physical properties which has never been considered by using volcanic ash as an aggregate. Also, if you use fine particles of SiO2 (silica, silica sand, or silicic acid anhydride) commonly called silica fume together with Portland cement, Ca (OH) 2 in the cement reacts with the partially water-soluble silicic acid H2SiO3, The so-called pozzolanic reaction of producing CaSiO3 which is an insoluble silicate is already well known knowledge, and its application such as fly ash cement and pozzolan concrete is already well known.

However, the above-mentioned difficult problems cannot be solved by only these known knowledge and techniques. That is, it is impossible to stably solidify a large amount of the above-mentioned hard-to-solidify objects at low cost, and most of the objects are such that they barely harden and easily disintegrate.

Therefore, the present inventor, without giving up,
Various pozzolanic materials such as volcanic ash fine sand and Kira (fine powdered silica sand called a waterfront that is generated as waste at a kiln factory) were mixed with various materials that should be solidified. It has been discovered that only certain special ones among them have the power to actually solidify the hard-to-solidify material, and the effect is exhibited only when volcanic ash with a particle size of 0.06 mm or less is also mixed. The inventors have found out that and arrived at the present invention.

In the special kira powder that exhibits such an action, fine particles of kira are further attached around the particles, which are fine and when dispersed in water,
It will become an aqueous colloidal liquid that will no longer precipitate due to Brownian motion. This is a radically different substance from the conventionally heat-treated pozzolanic material, which is heated and calcined, like silica fume produced in the aluminum refining process.

In a material such as sludge or zeolite, which is hard to solidify, the special kira is 0.02 to 1% by weight, preferably 0.1 in terms of the total amount of solid matter.
〜0.2wt% was mixed, and at the same time, 1 to 20 volcanic ash with a particle size of 0.06mm or less, which was previously discarded as a troublesome substance
% By weight, preferably 3-5% by weight.

The above-mentioned numerical limits are set because the solidification is not sufficient and is not practical unless the amount of the mixture is reached, and even if the amount is exceeded, the solidification is rather inhibited. It is from Shirasu.

In the present invention, cement is no longer the main character, but rather serves as a binder for solidification. However, when cement was used, the solidified product, namely concrete, was far superior to ordinary concrete in strength and heat resistance.

Next, a method for fixing the accumulated sludge layer which reaches a depth of, for example, a dozen or so meters will be described. That is, the material to be solidified as described above, for example, 1 to 20 W of volcanic ash with a particle size of 0.06 mm or less in the same sludge
%, A special killer of fine particles that can be an aqueous colloidal solution.
02 to 1 W% was added, and if necessary, silica sand, cement, etc. were added to form a wet soil, which was dropped onto the accumulated sludge layer,
It is laminated to a thickness of about 30 cm suitable for spreading and spread, and a wet mixture containing the same material, but cement, is further sprinkled on it, and is stacked to a thickness of about 30 cm. On top of that, water is sprinkled on it or it is left in natural rain to give it moisture and harden it to form a solid ground. This made it look like a lid on a huge pile of sludge, but it turned out that this could be a solid ground that is equivalent to fixing all the sludge. Although the reason will be described later, this makes it possible to form various structures by, for example, pouring concrete on the structure.

The solidified product obtained by the present invention is
It became clear that unlike ordinary concrete, it is extremely resistant to high heat, relatively lightweight, and rich in heat insulation, acid resistance, and seawater resistance. In particular, regarding the heat resistance, even if it is heated to such an extent that a solidified product is sprayed with a burner flame or the like to be ceramicized, it does not crack or significantly change, and becomes a stronger ceramic-like material. Therefore, for example, if a glaze is applied to the surface, a fine glaze-sintered product can be obtained.

From such characteristics, the solidified product of the present invention can be defined as a kind of new ceramic. Examples of applications include equipment and parts of equipment that require high heat resistance and low thermal conductivity, guide rails that utilize corrosion resistance, containers that utilize heat insulation, hulls that utilize light weight and seawater resistance, and oceans. Examples include constructs.

[0017]

According to the present invention, it has been completely beyond the conventional wisdom and expectations that the hard-to-solidify material, which has been considered to be substantially impossible to solidify or fix, could be easily solidified. , It is estimated that this is due to the following actions.

First, delicate silica sand is made into a stable colloid by Brownian motion. When we knead the mud with the volcanic ash fine sand using a special killer that has actually become an aqueous colloid solution, it can be seen that the water mixed in it is separated by various solid particles, but The colloidal particles of Kira (silica) are finer and continue the Brownian motion actively in their respective water contents. In addition to the fact that fine particles are fine particles and have a large surface area, when such movement is applied, their constituents, SiO2, quickly change to water-soluble silicic acid H2SiO3, and subsequently react with calcium ions to form insoluble silicates. It is considered that the pozzolanic reaction of producing CaSiO3 proceeds extremely rapidly.

On the other hand, volcanic ash fine sand having a particle size of 0.06 mm or less has a non-spherical and acicular shape, and its aggregate forms a tough skeletal structure by a kind of meshing effect. . Further, this skeletal structure is more completely formed by spreading the wet material.

In other words, it is considered that the Brownian motion of the special particles of the ultrafine particles present in the gaps of the fine skeleton causes the pozzolanization to proceed rapidly to form a solidified solid compound with the skeleton structure.

The cement plays a role as a connecting material for supporting or reinforcing the fine skeleton structure in which the solidification reaction proceeds, and at the same time, supplies the calcium ions necessary for the pozzolan reaction.

Even when a layer containing such ultrafine particle kira and volcanic ash fine sand is provided on a huge sludge layer or other soft ground, the solidified layer may have a toughness due to the meshing effect of the volcanic ash fine sand. It forms a tougher ground than you can imagine, so that it can withstand a large load even if it is an uncured soft material.

Further, the pozzolanic product that fills the voids has a function of strongly blocking harmful substances such as sludge and bad odors from coming out.

According to the present invention, unlike ordinary concrete, cement has a supporting role. Therefore, even if it is strongly heated in a burner, a melting furnace, etc., cracks due to the explosive action of the cement disappear and the degree of deformation Also decreases. Therefore, by acting as a binder or skeletal material for cement or volcanic ash fine sand, it is possible to increase the size of ceramics, which is unthinkable in conventional ceramic products.

[0025]

[Example 1] Shirasu produced in Kagoshima Prefecture (having a particle size of 0.06 mm or less) is used as a sludge (clayy soil, organic spoilage such as waste from rivers and fish meals, and sea sand) in Omura Bay, Nagasaki Prefecture. Kneading approximately 20 W% of fine powder) and approximately 8 W% of Portland cement, respectively, and special kira (containing about 10 W% of fine particles as a by-product of silica sand refining in glass manufacturing) equivalent to about 8 W% of the cement. And left it,
A cured product comparable to ordinary concrete was obtained in almost the same time. By the way, even if ordinary volcanic ash, kira, pozzolan cement, silica fume, etc. were used, a cured product having strength and durability like concrete could not be obtained.

[0026]

Example 2 10 parts by weight of artificial zeolite made from Shirasu, 100 parts by weight of Portland cement, 100 parts by weight of raw shirasu in the above example, 8 parts by weight of special killer in the above example, lapilli 3
0 parts by weight and an appropriate amount of water are kneaded in a predetermined mixing order in a green concrete state and molded. The next day, in the semi-hardened state, it is divided into crushed stones and left to fully harden. The crushed stone obtained is a completely cured product that could not be obtained with other inorganic hardeners, never dissolved or dispersed in water, and unlike when hardened with a resin, zeolite is It did not interfere with the ability to adsorb heavy metal ions in water.

[0027]

[Example 3] Instead of the Shirasu from Kagoshima of Example 1, volcanic ash and gravel from Fugendake, Nagasaki Prefecture are used, and a wave-eliminating block (tetrapot) is molded together with some ligulin sulfonic acid-based admixture. In addition, seawater-resistant concrete for fish reefs and seaweed beds will be used.

[0028]

[Example 4] In the concrete of the above example, hard-to-solidify radioactive waste is mixed and formed into a lump, and the outer shell is further solidified with the same volcanic ash concrete and submerged in the seabed to be the final disposal measure for radioactive waste. .

[0029]

[Example 5] The artificial zeolite of Example 2 was replaced with a black magnetite powder produced in a magnetite mine, which was kneaded with an omni mixer. As a result, a similarly hardened product was obtained although it should not harden in concrete. The powder has already been considered to be used for improving the health or the environment due to the magnetic effect and the negative ion effect, but it was possible to make it into a product easily by solidifying.

[0030]

Example 6 The same 3: 1 mixture of shirasu and special kira was kneaded in a wet state on a soft ground on which sludge was accumulated for a few dozen meters in the same manner and dropped by a bulldozer or the like. It is pressed to form a layer with a thickness of 30 cm, and a wet mixture prepared by adding 1/5 part by weight of Portland cement and an appropriate amount of water containing a ligrinsphonic acid-based admixture to the mixture is sprayed and spread thereon. Press to further form a 30 cm thick layer and let stand naturally until natural rainwater is obtained. After curing,
In addition, ordinary fresh concrete or volcanic ash concrete is poured to form a surface layer, which is used as a reinforced ground for airports.

[0031]

[Example 7] A large-sized concrete-like molded product is formed with the composition according to Examples 1 and 3, and a glaze is applied if necessary, and a burner flame is sprayed on the surface thereof to heat it to a sintering or melting temperature. . As a result, a large, non-deformable ceramic material that could not be obtained with conventional ceramic raw materials was obtained, and it was possible to impart corrosion resistance, which is lacking in iron and concrete.

[0032]

As described above, according to the present invention, by using only inorganic materials which are relatively low in cost, abundant in resources and durable, hard-to-hardenable materials and soft materials which are not hardened by conventional concrete or setting materials are used. The ground can be solidified or fixed on a large scale, and the solidified material has extremely high physical properties and durability, so it can be used not only as a new molding or construction material, but also for waste pollution prevention and environmental conservation. There is an effect that you can contribute.

Claims (7)

[Claims] 1. A volcanic ash having a particle size of 0.06 mm or less in terms of the total amount of solid matter is added to 1 to 1 of mud containing calcium ions.
A method for solidifying mud, which comprises mixing 20% by weight and 0.02 to 1% by weight of fine particles of silica particles which are sufficient to form an aqueous colloidal solution. 2. A mud of 1 to 20% by weight of volcanic ash having a particle size of 0.06 mm or less and 0.02 to 1% by weight of fine particles of silica sand sufficient to form an aqueous colloidal solution in terms of the total amount of solid matter. % And cement as a binder, a method for solidifying mud. 3. In the mud body, in terms of the total amount of solid matter,
Add 1 to 20% by weight of volcanic ash with a particle size of 0.06 mm or less, and 0.02 to 1% by weight of fine particles of silica sand, which is sufficient to form an aqueous colloidal solution, and add silica sand or cement if necessary. In the unsolidified state, the mixed mixture was laminated on the sedimented sludge layer and spread, and 1 to 20 volcanic ash with a particle size of 0.06 mm or less in terms of solid matter was added to the mud body containing calcium ions. % By weight, 0.02 to 1% by weight of special silica fine particles consisting of silica sand sufficient to form an aqueous colloidal solution, and a mud body mixed with cement as a binder and, if necessary, a mixture of silica sand, cement, etc. A sludge layer characterized in that a wet material is sprayed in an unsolidified state, laminated and cured by giving water to it, and if necessary, a concrete layer is further provided thereon. Fixing method. 4. A method for hardening mud, which comprises blending sludge, shirasu partially containing fine particles having a particle size of 0.06 mm or less, and a special killer having a particle size capable of forming an aqueous colloidal solution. 5. A volcanic ash having a particle size of 0.06 mm or less in terms of the total amount of solid matter is added to 1 to 1 of mud containing calcium ions.
20% by weight and 0.02 to 1% by weight of fine particles of silica sand, which is sufficient to form an aqueous colloidal solution, were mixed with silica sand and cement as needed, and mixed into a tetrapot, pile, curb, fish reef, etc. A molded product characterized by being formed into a molded product and, if necessary, fired. 6. The method for hardening mud according to any one of claims 1 to 4, wherein the special killer is silica having a particle size capable of forming a colloidal solution. 7. The molded product according to claim 5, wherein the special killer is silica having a particle size capable of forming a colloidal solution.