JP5732657B1 - Silica sol grout production apparatus and production method - Google Patents

Abstract

Silica sol capable of producing a high-concentration silica sol grout with high efficiency without causing partial gelation, and further using a raw water glass solution or mixing seawater as water An apparatus and method for manufacturing a grout are provided. A silica sol grout production apparatus for obtaining a silica sol grout by mixing a silica solution with an acidic solution. An agitation tank 1 whose upper surface is opened and stores an acidic solution, an agitator 2 disposed in the agitation tank 1, and a non-contact position with respect to the acidic solution stored in the agitation tank 1, And an injection nozzle 3 for injecting. [Selection] Figure 2

Description

  The present invention relates to improvements in a silica sol grout production apparatus and production method (hereinafter also simply referred to as “production apparatus” and “production method”).

  In recent years, non-alkaline silica solutions have been used to prevent liquefaction and the like. Since liquefaction prevention injection is ground strengthening against earthquakes that do not know when it occurs, long-term durability is required. Therefore, it has been found that it is appropriate to use silica grout in an acidic region produced by removing an alkali that causes deterioration of water glass with an acid. However, in order to economically perform large-scale liquefaction prevention injection in recent years, it is necessary to perform rapid construction using a large-capacity acidic silica production apparatus.

  However, it has been difficult to produce a large amount of injection solution using a large container because a heterogeneous gel precipitates in the conventional method. The reason for this is that, when a non-alkaline silica grout is conventionally produced, when a method of removing the alkali of water glass with an acid is used, partial gelation occurs when passing through the neutral region from the alkaline region. This is because it was difficult to obtain a uniform silica grout having the target pH and specific gravity.

  FIG. 1 is a graph showing the relationship between the pH of a silica solution, the gelation time, and the silica concentration. Case 1 in FIG. 1 is that when an acid is added to water glass to make an acidic silica solution, the gelation time passes through a neutral region where the pH is close to instantaneous setting, so a homogeneous acidic silica solution is produced. Can not. For this reason, as shown in Case 2, a method of adding water glass to the acidic liquid is used. As a method of making acidic silica liquid, water glass and acid are mixed and mixed in excess with a Y-shaped tube (Y-shaped method), or excessive acidic liquid is measured in a container and the acidic liquid is measured. A method of spraying and mixing a predetermined amount of water glass is used (batch method). Among them, in the Y-shaped manufacturing method, it is difficult to mix the liquid A (water glass liquid) and the liquid B (acidic liquid) at an accurate mixing ratio, and thus the bulk silica is likely to be precipitated. On the other hand, a batch-type production method that sequentially supplies the A liquid and the B liquid into the container is preferable because the A liquid and the B liquid can be accurately measured and mixed.

  Thus, in order to prevent the occurrence of partial gel, it is necessary to use a technique such as excessive mixing of acid so that rapid gelation does not occur, or diluting and mixing water glass. In the case of silica sol grout with excessive addition of acid, it is necessary to consider the influence on the environment and structures. In diluted water glass, the concentration of water glass is low, and sufficient high strength cannot be obtained in improved ground. was there.

  As a prior art related to the production of silica sol, for example, Patent Document 1 discloses that the total amount of dilution water necessary to achieve the final desired silicic acid content in obtaining strongly acidic silica sol by adding water glass into acid. Is added to the water glass stock solution to prepare a diluted water glass solution, and then the inside of the cylindrical portion of the mixing apparatus is composed of a cylindrical portion whose upper end is sealed and a conical portion which is connected to the lower end and is provided with a discharge port at the lower portion. In addition, while continuously moving a large amount of diluted water glass liquid introduced at right angles to the axis, a small amount of strong acidic mineral acid liquid is continuously pressurized and injected perpendicularly thereto, and both liquids are A technique for swirling and mixing in a turbulent state is disclosed. Patent Document 2 uses a Y-shaped reaction apparatus in which two raw material supply pipes with constricted parts are joined and connected to one discharge pipe at the joining part. Non-alkaline silicic acid for ground injecting chemical solution that supplies acidic solution and sodium silicate solution from the two raw material supply pipes at a predetermined flow rate, collides and mixes both components at the junction, and flows out from the discharge pipe at a predetermined flow rate A method for producing an aqueous solution is disclosed.

  Furthermore, in Patent Document 3, when manufacturing a non-alkaline ground hardening chemical by mixing an aqueous solution of water glass and an aqueous solution of a curing agent, first and second storages for storing an aqueous solution of water glass and a curing agent, respectively. A tank, a first supply system connected to the first storage tank for supplying an aqueous solution of water glass, a second supply system connected to the second storage tank for supplying an aqueous solution of a curing agent, and first and second supply systems A confluence pipe connected to the downstream side of the merging pipe, a mixer connected to the outlet side of the merging pipe, and a third storage tank installed on the outlet side of the mixer for storing the non-alkaline ground hardening chemical, The outlet side of the junction pipe is formed to have a larger diameter than the inlet side, the inlet side is disposed above the outlet side, and the downstream side of the first supply system and the second supply system connected to the inlet side is further above the inlet side Non-alkaline ground hardening medicine arranged in Manufacturing apparatus is disclosed.

  Furthermore, in Patent Document 4, mixing is performed so that a cylindrical mixing tank having a predetermined size and a center line perpendicular to the bottom surface of the mixing tank are positioned at a predetermined distance downward and upward from the bottom surface. Using a non-alkaline silicic acid aqueous solution manufacturing device composed of a nozzle arranged in the tank, an acidic agent aqueous solution is loaded into the mixing tank, and water glass liquid is injected and mixed into the aqueous solution from the tip of the nozzle at a predetermined pressure. A method for producing a non-alkaline aqueous silicic acid solution is disclosed.

Japanese Patent Publication No. 5-75692 JP 2005-194463 A Japanese Patent No. 4507339 (Japanese Patent Laid-Open No. 2001-247865) Japanese Patent Publication No. 7-8723

  In recent years, there has been a demand for rapid construction of large-scale ground improvement work, and for this reason, further speed-up is required for the production of grout at the time of pouring. In order to increase the strength of the improved ground, it is effective to use a high concentration silica sol grout. From this point of view, there is a need for a technique for producing a high-concentration silica sol grout more rapidly than in the past.

  However, in the merging type manufacturing apparatus as disclosed in Patent Documents 1 to 3, it is difficult to accurately merge the two liquids, and the amount of liquid to be merged is likely to vary. When trying to manufacture, there existed a problem that a partial gel was easy to produce. Moreover, in the technique which concerns on patent document 1, if water glass is not diluted, silica sol cannot be manufactured, but there also existed a difficulty that water glass could not be used with a stock solution. Furthermore, when seawater was used as the kneaded water, it instantly gelled and could not be used.

  On the other hand, there is a batch type manufacturing apparatus as disclosed in Patent Document 4, but in the case of the batch type, when the stirring tank is enlarged, mixing tends to be insufficient, and there is a possibility that accurate mixing cannot be performed. . On the other hand, if a small agitation tank is used, sufficient and accurate mixing can be performed, but the amount of silica sol that can be produced at one time is reduced, and the production efficiency is lowered.

  Accordingly, an object of the present invention is to produce a high-concentration silica sol grout with high efficiency without causing partial gelation, and further to use a stock solution of water glass or use seawater as kneaded water. Another object of the present invention is to provide a silica sol grout production apparatus and production method.

As a result of the study by the present inventors, it was found that when an acidic silica solution was to be produced in large quantities, it was difficult to stir homogeneously in a large container, and massive silica was likely to be generated.
The present inventors have completed the present invention by elucidating the cause as follows.
First, the conventional batch type mixing container is cylindrical or quadrangular, but when water glass is mixed in an acidic liquid in a cylindrical container, the large container only mixes around the mixing axis. It was found that the mixed solution co-rotates, the flow velocity is reduced in the vicinity of the outer peripheral wall of the container, the mixing becomes insufficient, and silica is likely to precipitate. In addition, in the case of a square columnar container, it was found that the mixed solution co-rotated near the center and stagnated at the corners, and mixing was not sufficiently performed as a whole. On the other hand, in order to prevent the generation of the partial gel, it is also important for the method of joining the two liquids.
From the above points, the present inventors have intensively studied from the viewpoints of the shape of the stirring tank used for producing the silica sol grout and the mixing conditions of the acidic solution and the silica solution, and as a result, the present invention has been completed.

That is, the silica sol grout production apparatus of the present invention is a silica sol grout production apparatus in which a silica solution is mixed with an acidic solution to obtain a silica sol grout.
A stirring tank for storing the acidic solution; and a stirrer disposed in the stirring tank, the stirring tank having a polygonal cylindrical shape from a pentagon to a dodecagon, and the polygonal cylindrical shape A substantially semi-cylindrical protrusion is provided on the inner peripheral surface of the stirring tank.

Furthermore, the silica sol grout production apparatus of the present invention is a silica sol grout production apparatus for obtaining a silica sol grout by mixing a silica solution with an acidic solution.
A cylindrical stirring tank for storing the acidic solution and a stirrer disposed in the stirring tank are provided, and a substantially semi-columnar protrusion is provided on the inner peripheral surface of the cylindrical stirring tank. It is characterized by this.

  In this invention, it is preferable that the said protrusion part is provided in three or more places on the internal peripheral surface of the said stirring tank.

The method for producing a silica sol grout according to the present invention is a method for producing a silica sol grout in which a silica solution is mixed with an acidic solution to obtain a silica sol grout.
Using the production apparatus of the present invention having the specific shape, the acidic solution is stored in the stirring tank, and the silica solution is added to the acidic solution while stirring the acidic solution in the stirring tank. It is characterized by this.

Further, the method for producing a silica sol grout of the present invention is a method for producing a silica sol grout in which a silica solution is mixed with an acidic solution to obtain a silica sol grout.
The acidic solution is stored in a stirring tank having an upper surface opened, and the silica solution is sprayed from above onto the acidic solution while stirring the acidic solution in the stirring tank. .

  In the method for producing the silica sol grout of the present invention, the silica glass solution can be used without diluting a stock solution of water glass, and seawater can be used as kneaded water. Moreover, the addition of the silica solution to the acidic solution can be performed with a time interval.

  According to the present invention, high-concentration silica sol grout can be produced with high efficiency without causing partial gelation, and further, use of a stock solution of water glass or use of seawater as mixing water It is also possible to realize a silica sol grout production apparatus and production method that are possible.

It is a graph which shows the fluctuation | variation of pH of a liquid mixture. (A), (b) is a schematic explanatory drawing which shows an example of the manufacturing apparatus of the silica sol grout of this invention. It is typical horizontal sectional drawing which shows the conventional stirring tank. (A), (b) is typical horizontal sectional drawing which shows an example of the stirring tank which concerns on this invention. (A), (b) is typical horizontal sectional drawing which shows the other example of the stirring tank which concerns on this invention. It is a typical sectional view of the horizontal direction which shows other examples of the stirring tank concerning the present invention. It is a graph which shows the change of the ratio of the mixing speed at the time of changing the number of injection nozzles.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIGS. 2A and 2B are schematic explanatory views of an example of the silica sol grout production apparatus of the present invention. The apparatus for producing a silica sol grout of the present invention is used to obtain a silica sol grout by mixing a silica solution with an acidic solution. The agitator 2 disposed in the agitation tank 1 and the acidic solution A stored in the agitation tank 1 are not in contact with each other, that is, above the liquid level of the acidic solution A and after mixing. An injection nozzle 3 for injecting the silica solution B is provided at a position above the liquid level of the mixed liquid. Moreover, the code | symbol 4 in a figure shows the storage tank which stores the silica solution B. FIG.

  In the production apparatus of the present invention, since the silica solution B can be non-contact sprayed to the acidic solution A through the spray nozzle 3, it does not pass through the alkali region where the alkali of the water glass is easily neutralized, and the large capacity of the stirring tank Even when the production rate is improved by the conversion, the acidic solution A and the silica solution B can be uniformly mixed while preventing the generation of the partial gel. Moreover, since the injection nozzle 3 is arranged at a position where it is not in contact with the acidic solution A as shown in FIG. 2, the two liquids directly merge as in the case where the injection nozzle is arranged in the acidic solution. This eliminates the problem that partial gel is likely to occur at the portion where the film is formed. Moreover, since it is a production by a batch system, since the predetermined concentration can be blended in an accurate amount so that the acidic solution A becomes excessive with respect to the silica solution B, Partial gel is unlikely to occur. As described above, according to the present invention, a high-concentration silica sol grout is achieved without increasing the production speed without causing a problem of partial gel in a batch-type production apparatus that has conventionally been difficult to mix with a large volume. It became possible to manufacture.

  In the present invention, jetting the silica solution from the tip of the jet nozzle 3 is one factor that does not cause partial gel. This is due to the following reasons. That is, in the non-contact method in which the silica solution B is jetted from the air above the water surface in the present invention, the silica solution B is dripped into the acidic solution A in a wide range by jetting, Since the amount is small and this is stirred and mixed in the acidic solution A, when one grain is seen, it immediately becomes an acidic side state without passing through the region of transition from the alkaline side to the acidic side in FIG. Since it becomes silica, no partial gel is produced. On the other hand, in the conventional method of spraying water glass in an acidic liquid, the amount of water glass is larger than the acidic liquid in the vicinity of the injection hole, and therefore, the region of transition from the alkali side to the acidic side in FIG. In this case, a partial gel is formed. In particular, since the tendency is strong when the silica concentration is high, it is difficult to produce a thick silica solution.

  According to the present invention, since silica sol grout can be produced in a large amount at a time, the number of construction days can be reduced as compared with the conventional method, and the cost can be reduced. Moreover, since the acidic solution A and the silica solution B can be mix | blended correctly as above-mentioned, a silica density | concentration can be made higher than before and a high intensity | strength ground improvement is possible. Furthermore, since the acidic solution A and the silica solution B can be accurately blended, it is not necessary to add an excessive amount of acid, and the amount of acid used can be minimized, so that the environment is excellent.

  In the present invention, by providing at least one injection nozzle 3, water glass diffuses in the liquid and falls into the acidic liquid, so that the desired effect of the present invention can be obtained. As shown in (a) in the figure, it is preferable to provide a plurality of, for example, 3 to 6, from the viewpoint of uniform mixing. Moreover, the injection pressure of the injection nozzle 3 can be 0.1 MPa or more, for example, 0.1-0.5 MPa suitably. Furthermore, in the present invention, the conditions of the stirrer 2 are not particularly limited, but those having a shear stirring ability are preferable. Although not shown, in the production apparatus of the present invention, a flow meter can be used for managing the mixing amount. Such a flow meter may be any of an electromagnetic type, an ultrasonic type, an impeller type and the like.

  The amount of silica sol grout that can be produced at one time is 100 liters to 150 liters in a conventional batch production apparatus, and 65 liters to 150 liters per minute in a combined production apparatus. On the other hand, in the production apparatus of the present invention, for example, 200 to 400 liters of silica sol grout can be produced at a time.

  In the manufacturing apparatus of the present invention, the desired effect can be obtained by using the above injection nozzle, but instead of using the injection nozzle, a stirring tank having a predetermined shape is used. The same effect can be obtained by using it. Specifically, in another embodiment of the present invention, a stirring tank having a pentagonal to dodecagonal polygonal cylindrical shape is used. That is, a cylindrical stirring vessel having a horizontal cross-sectional shape of a pentagonal to dodecagonal polygonal shape is used.

  That is, as a conventional stirring tank, a cylindrical one as shown in FIG. 3 (a) was generally used, but when the liquid stored in the cylindrical stirring tank was stirred with a stirrer, The stirrer speed becomes slower toward the outer peripheral side, so as the capacity of the agitation tank increases and the diameter of the tank increases, uniform mixing becomes difficult, and the entire liquid inside the tank rotates together with the agitator. Even if the stirrer is rotated, the liquid is not mixed, and there is a problem that the concentration is not uniform. Therefore, as a result of the experiments by the present inventors, in the present invention, the shape of the stirring tank was improved to have the specific polygonal cylindrical shape. Thus, by making the shape of the inner wall of the stirring vessel polygonal, it is possible to prevent the occurrence of co-rotation as in the case where the cross-sectional shape is a circle. On the other hand, if the shape of the inner wall of the stirring tank is a quadrangle as shown in FIG. 3 (b), the liquid tends to stay at the corners, which also prevents uniform mixing. The angle of the corner in the cross section is an obtuse angle. Further, if the cross-sectional shape exceeds the dodecagon, the angle of the corner becomes too large and substantially close to a circle, so it is necessary to make the polygon less than the dodecagon. Preferably, a stirring vessel having a pentagonal to octagonal polygonal cylindrical shape is used. FIG. 4 shows a schematic cross-sectional view in the horizontal direction of (a) a pentagonal stirring tank and (b) a hexagonal stirring tank according to the present invention.

  Therefore, in the production apparatus of the present invention, the use of the stirring tank having the specific polygonal cylindrical shape described above enables generation of partial gel even when the production rate is increased by increasing the capacity of the stirring tank. The acidic solution and the silica solution can be mixed uniformly while preventing the above. In particular, by combining the manufacturing apparatus using the injection nozzle shown in FIG. 2 with the stirring tank having the specific polygonal cylindrical shape, the generation of the partial gel is more effectively suppressed, and the high-concentration silica sol grout is once produced. Can be manufactured in large quantities.

  5A and 5B are schematic cross-sectional views in the horizontal direction of other stirring tanks according to the present invention. As shown in the figure, in the present invention, it is preferable to provide substantially semi-cylindrical protrusions 15A and 15B on the inner peripheral surfaces of the polygonal cylindrical stirring tanks 11A and 11B. FIG. 5 (a) shows a state in which a substantially semi-cylindrical protrusion 15A is provided on the inner peripheral surface of a pentagonal cylindrical stirring tank 11A, and FIG. 5 (b) shows a hexagonal cylindrical stirring tank 11B. The state which provided the substantially semi-columnar protrusion part 15B in the inner peripheral surface is shown. Thus, it is preferable to provide a protrusion on the inner peripheral surface of the stirring tank because a turbulent flow is generated during stirring and the liquid is further easily stirred and mixed. If one or more protrusions are provided, the desired effect can be obtained. However, as shown in the drawing, it is preferable that three or more protrusions are provided at equal intervals on the inner peripheral surface of the stirring tank. From the viewpoint of easy mixing. Here, as shown in the figure, the projecting portion is provided at a substantially central portion of the sides constituting the polygon, among the inner peripheral surfaces of the polygonal cylindrical stirring tanks 11A and 11B.

  FIG. 6 is a schematic cross-sectional view in the horizontal direction of still another stirring tank according to the present invention. As shown in the drawing, in the present invention, a stirring tank in which a substantially semi-columnar protrusion 25 is provided on the inner peripheral surface of a cylindrical stirring tank 21 can also be used. As described above, if the cylindrical stirring tank is used as it is, there will be a problem that the liquid will be co-rotated and the liquid will not be sufficiently mixed. However, by providing a protrusion on the inner peripheral surface, the occurrence of co-rotation is prevented. In addition, by generating the turbulent flow, the whole can be mixed sufficiently, and the desired effect of the present invention can be obtained.

  The embodiment shown in FIGS. 5 and 6 can be carried out only by attaching a plurality of parts to the inner peripheral surface of each shape of the stirring tank, and further improvement of the stirring tank itself is unnecessary, so that the embodiment is easy to implement. It also has the advantage of being.

  Moreover, since the manufacturing apparatus of the present invention has a simple structure and is relatively small, it can also be used by being mounted on a vehicle.

  In the method for producing a silica sol grout of the present invention, the silica solution is added to the acidic solution while stirring the acidic solution in the stirring tank using the production apparatus of the present invention having the stirring tank having the specific shape. Alternatively, the silica solution is jetted and mixed with the acidic solution from above while stirring the acidic solution in a stirring tank having an open top surface, and both methods may be used in combination. Thereby, while preventing generation | occurrence | production of a partial gel, an acidic solution and a silica solution can be mixed uniformly, and it becomes possible to manufacture a high concentration silica sol grout in large quantities at once.

  In the present invention, as the acid used in the acidic solution, inorganic acids such as sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, sulfamic acid, and mixed acids thereof can be used. In addition to silica such as active silica, colloidal silica, and metal silica, the silica solution can be used without diluting a stock solution of water glass, and a plurality of types selected from these may be used in combination. Here, when using a stock solution of water glass as the silica solution, it is preferable to add the silica solution to the acidic solution with a time interval.

  Active silica grows to a silica particle size of 1 to 5 nm and gels after several days. Colloidal silica stabilized by weak alkalinity by adding a small amount of caustic alkali or water glass is the above-mentioned active silica. By heating, it is concentrated and granulated, and the pH is adjusted to 9 to 10 and stabilized. The colloidal silica thus obtained has a silica concentration of 5% or more, usually about 30%, and a particle size of 5 to 20 nm.

  In addition, although the specific gravity of the dilution water glass at the time of manufacture of the conventional silica sol was up to 1.05-1.15 (1.15 or less), in the present invention, those having a specific gravity of 1.15 or more are used. Possible, preferably 1.25 to 1.43.

  In the present invention, since an acidic solution and seawater can be mixed first and then a silica solution can be mixed, even if seawater is used as mixed water, it is not directly affected by seawater. There is a merit. Thereby, cost efficiency can be improved more.

  In the present invention, when the silica sol is produced, each component can be charged into the stirrer in the order of water, acidic solution, and silica solution. The silica solution includes water glass and active silica colloid in this order. It is preferable to do. However, water and the acidic solution may be added simultaneously, or water glass and active silica colloid may be added simultaneously. Moreover, it is preferable that water glass is injected and injected vigorously using a pump or the like among silica solutions.

  Hereinafter, the present invention will be described in more detail with reference to examples. Of course, the present invention is not limited by these examples.

  Manufacture of silica sol grout using a manufacturing device in which a stirrer (manufactured by Silverson Nippon Co., Ltd., versatile batch mixer) is placed inside a stirring tank (capacity: 150 liters) having a pentagonal polygonal cylindrical shape Went.

  Fill the stirring tank with phosphoric acid (specific gravity 1.58) and place the silica solution shown in Table 1 below in a non-contact position with respect to phosphoric acid while rotating the stirrer under the condition of 1500 rpm. Sprayed into the stirring tank at a jetting pressure of 0.1 MPa using a single spray nozzle (with jetting) or supplied as it is by free fall into the stirring tank (no jetting) and mixed with phosphoric acid did.

＊１）原液５号水ガラス：比重（２０℃）１．３２、ＳｉＯ_２：２５．５質量％、Ｎａ_２Ｏ：７．０３質量％、モル比３．７５。
希釈５号水ガラス：原液５号水ガラス８０リットルを希釈水１２０リットルで希釈したもの。

* 1) Stock solution No. 5 water glass: specific gravity (20 ° C.) 1.32, SiO ₂ : 25.5% by mass, Na ₂ O: 7.03% by mass, molar ratio 3.75.
Dilution No. 5 water glass: 80 liters of stock No. 5 water glass diluted with 120 liters of dilution water.

  In addition, as can be seen from the graph of FIG. 1, in the conventional manufacturing method, as shown in Case 1, a mixed solution in the acidic region is produced from the alkaline region through the neutral region. Therefore, as in Case 2, the pH shifts from the acidic region to weakly acidic, so that a stable blending solution can be produced and blending is possible with only a small amount of reactants.

  As a result, when a silica sol was produced using a diluting water glass or a stock solution water glass as a silica solution using a stirring tank having a pentagonal polygonal cylindrical shape, the generation of a partial gel was not performed even without the use of an injection nozzle. There wasn't.

  Next, using the same production apparatus as described above, silica sol grout was produced with the formulation shown in Table 2 below. First, water and 75% sulfuric acid are sequentially added to the stirring tank, and No. 3 water glass is placed in a non-contact position with respect to the liquid in the stirring tank while rotating the stirrer at a rotation speed of 1500 rpm. The mixture was sprayed into a stirring tank at a spray pressure of 0.1 MPa using a spray nozzle and mixed with water and 75% sulfuric acid.

＊２）３号水ガラス：比重（２０℃）１．４１、ＳｉＯ_２：２９質量％、Ｎａ_２Ｏ：９．０５％、モル比３．２。

* 2) No. 3 water glass: specific gravity (20 ° C.) 1.41, SiO ₂ : 29% by mass, Na ₂ O: 9.05%, molar ratio 3.2.

  The theoretical values of the kneaded blended liquid (silica sol grout) obtained based on the blend shown in Table 2 are shown in Table 3 below.

  Table 4 below shows the test results obtained in each example. When compared with the theoretical values in the above table, the specific gravity was within 0.01. Moreover, about pH, it was in the range of the theoretical value.

  Next, silica sol grout was manufactured with the formulation shown in Table 5 below using the same manufacturing apparatus as described above.

The following silica solutions were used.
Colloidal silica: An alkali solution added to a water glass aqueous solution treated with a cation exchange resin, which is condensed and stabilized by heating. SiO ₂ : about 30% by mass, Na ₂ O : Colloidal silica exhibiting physical properties of 0.7% by mass or less, specific gravity (20 ° C.): 1.21-1.22, pH: 9-10.

The water glass was treated with an ion exchange resin to remove most of the alkali, and colloidal silica manufactured by ADEKA Co., Ltd. obtained by granulation was used.
The molar ratio of the water glass used is between 0.5 and 4.5, preferably 3-4.

  Using the above blend A, first, water and phosphoric acid are sequentially filled in a stirring tank, and No. 5 water glass is placed in a mixture of water and phosphoric acid while rotating the stirrer at a rotation speed of 1500 rpm. Sprayed into the agitation tank at an injection pressure of 0.1 MPa using an injection nozzle (in liquid) or an injection nozzle (outside of liquid) disposed at a position that is not in contact with water and phosphoric acid. And mixed with phosphoric acid. Table 6 below shows the test results obtained in each example.

  Next, using the above blend B, first, water and phosphoric acid are sequentially filled in the stirring tank, and while the stirrer is rotated at a rotational speed of 1500 rpm, No. 5 water glass and colloidal silica are sequentially added to water and phosphorus. Stir at an injection pressure of 0.1 MPa using an injection nozzle (in liquid) placed in a mixed solution of acid, or an injection nozzle (outside of liquid) placed in a non-contact position with respect to water and phosphoric acid. It was sprayed into the tank and mixed with water and phosphoric acid. Table 7 below shows the test results obtained in each example.

  Next, silica sol grout was produced in the same manner as in Experimental Example 1 except that the number of spray nozzles was changed in the same production apparatus as described above. The results are shown in Table 8 below and FIG.

  From the results in the above table, it was confirmed that increasing the number of injection nozzles increased the speed of mixing the liquid, improved the production capability, and consequently shortened the construction time.

  Next, silica sol grout was produced in the same manner as in Experimental Example 1 except that the silica solution, the position of the injection nozzle, and the shape of the stirring tank were changed as shown in Table 9 below. Table 9 below also shows the test results obtained in each example.

＊）攪拌槽の大きさが大きいと部分ゲルができてしまい、使用不可となるが、小さければ使用可能である。

*) If the size of the agitation tank is large, a partial gel is formed and cannot be used, but if it is small, it can be used.

For example, when No. 3 water glass is used as the silica solution, and a pentagonal cylindrical stirring tank is used, if the position of the injection nozzle is outside the liquid, the silica (SiO ₂ ) concentration in the compounded liquid is 30. %, And when the position of the spray nozzle is inside the liquid, it can be used up to 20%. On the other hand, when a cylindrical tank is used, when the position of the injection nozzle is outside the liquid, it can be used up to a silica concentration of 20% in the liquid mixture, and the position of the injection nozzle is inside the liquid. Can be used up to 12%. Furthermore, when a rectangular cylindrical tank is used, when the position of the injection nozzle is outside the liquid, it can be used up to a silica concentration of 20% in the blended liquid, and when the position of the injection nozzle is inside the liquid Also, up to 12% can be used.

  From the above results, it can be seen that the best results can be obtained by a combination in which the injection nozzle is arranged outside the liquid using a pentagonal cylindrical stirring tank. In addition, when colloidal silica is further added, the silica concentration in a compounding liquid can be raised. Moreover, it is a substantially equivalent result also when the water glass in the range of 2.0-5.4 molar ratio is used.

  From the above, by making the shape of the stirring tank a polygonal cylinder, it is possible to produce silica sol grout without causing partial gelation even when the stirring tank is enlarged, and the silica concentration is further increased. Even in this case, it was confirmed that the silica sol grout can be produced without generating a partial gel by using the spray nozzle without contact with the liquid surface. It was also confirmed that the production efficiency can be improved by increasing the number of injection nozzles.

1, 11A, 11B, 21 Stirrer 2 Stirrer 3 Injection nozzle 4 Reservoir 15A, 15B, 25 Projection part A of substantially semi-cylindrical shape Acidic solution B Silica solution

Claims (8)

In a silica sol grout production apparatus for obtaining a silica sol grout by mixing a silica solution with an acidic solution,
A stirring tank for storing the acidic solution, and an agitator disposed within the agitation拌槽, the agitation拌槽is, have a dodecagon polygonal tubular pentagonal and polygonal tubular An apparatus for producing a silica sol grout, characterized in that a substantially semi-cylindrical protrusion is provided on the inner peripheral surface of the stirring tank . In a silica sol grout production apparatus for obtaining a silica sol grout by mixing a silica solution with an acidic solution,
A cylindrical stirring tank for storing the acidic solution and a stirrer disposed in the stirring tank are provided, and a substantially semi-columnar protrusion is provided on the inner peripheral surface of the cylindrical stirring tank. An apparatus for producing silica sol grout. The apparatus for producing a silica sol grout according to claim 1 or 2 , wherein three or more protrusions are provided on the inner peripheral surface of the stirring tank. In the method for producing silica sol grout, a silica sol grout is obtained by mixing a silica solution with an acidic solution.
The manufacturing apparatus according to any one of claims 1 to 3 , wherein the acidic solution is stored in the stirring tank, and the acidic solution is stirred with respect to the acidic solution while the acidic solution is stirred in the stirring tank. A method for producing a silica sol grout, comprising adding a silica solution. In the method for producing silica sol grout, a silica sol grout is obtained by mixing a silica solution with an acidic solution.
The silica sol grout is characterized in that the acidic solution is stored in a stirring tank having an upper surface opened, and the silica solution is sprayed from above onto the acidic solution while stirring the acidic solution in the stirring tank. Production method. The method for producing a silica sol grout according to claim 4 or 5 , wherein a water glass stock solution is used without dilution as the silica solution. The method for producing a silica sol grout according to any one of claims 4 to 6 , wherein seawater is mixed and used as water. The method for producing a silica sol grout according to any one of claims 4 to 7 , wherein the addition of the silica solution to the acidic solution is performed with a time interval.

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