Solidification material for non-fired bricks containing desert soil or dredged soil as raw materials, and manufacturing method and manual manufacturing device for non-fired bricks containing desert soil or dredged soil as raw materials using the solidification material

Abstract

Provided is a solidification material for an unburned brick that contains, as a raw material, desert soil or dredged soil, said solidification material being characterized by being obtained by mixing cement and an inorganic solidification material, wherein the inorganic solidification material contains, as essential components, silicon oxide, calcium chloride, and aluminum oxide.

Description

[Technical Field]

[0001] The present invention relates to a solidifying material for non-fired bricks containing desert soil or dredged soil as a raw material, and a manufacturing method and manual manufacturing device for non-fired bricks containing desert soil or dredged soil as a raw material using the solidifying material. [Background technology]

[0002] Historically, bricks have been widely used as building materials. For example, fired bricks are suitable for applications requiring strength, while so-called sun-dried bricks are used for applications requiring less strength. Natural soil, such as forest soil, black soil, and clayey soil, is generally used as the raw material for these bricks. Patent Document 1 proposes a method of producing unfired bricks by mixing natural soil and sand, adding cement as a solidifying agent, kneading the mixture while gradually adding water, placing the mixture in a mold, and drying it while still in the mold.

[0003] However, since the natural soil used as the raw material for bricks is suitable for agricultural land, using it to manufacture bricks would result in a decrease in agricultural land, and so some countries and regions have banned or restricted the use of natural soil on agricultural land for brick production.Furthermore, using coal as a fuel to fire bricks causes environmental pollution due to soot, heavy metals contained in the soot and ash, and carbon dioxide generated by combustion, so some countries and regions have banned the production of fired bricks.

[0004] Meanwhile, Patent Document 2 proposes the production of unfired bricks using volcanic ash clay (loam) construction waste as raw material, adding Portland cement (hereinafter simply referred to as cement) as a solidifying agent and sodium aluminate water, kneading the mixture, extruding it, and then drying and solidifying it. Patent Document 3 also proposes the production of colored unfired bricks. According to this method, instead of using cement as a solidifying agent, 100 parts by weight of raw material volcanic ash clay construction waste adjusted to a particle size of 5 mm or less is mixed with 15 to 65 parts by weight of a calcium-based solidifying agent such as slaked lime (calcium hydroxide) or calcium carbonate, and 5 to 20% by weight of a pigment and sand that has been thoroughly mixed in advance are mixed with the mixture, followed by molding, drying, and solidifying to produce unfired bricks. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2008-266110 [Patent Document 2] Patent Publication No. 2011-006308 [Patent Document 3] Patent Publication No. 2012-162428 Summary of the Invention [Problem to be solved by the invention]

[0006] The technologies of Patent Documents 2 and 3 eliminate the use of natural soil as a raw material for bricks and solve the problem of environmental pollution associated with fired bricks. However, in countries and regions where the use of natural soil as a raw material for bricks is prohibited or restricted, it is not always possible to obtain volcanic ash clay (loam), while there are countries and regions that require large quantities of high-strength unfired bricks for use in building structures.

[0007] On the other hand, there are countries that prohibit or restrict the use of natural soil as a raw material for bricks, and that have large amounts of desert soil (hereinafter referred to as desert soil) and dredged soil from rivers and ports (hereinafter referred to as dredged soil).If high-strength non-fired bricks could be produced using desert soil or dredged soil, as in Patent Documents 2 and 3, waste materials such as dredged soil could be effectively utilized, and problems such as a decrease in farmland and environmental pollution could be solved.

[0008] However, the construction waste soil used in Patent Documents 2 and 3 has relatively large particle sizes, while the particles of desert soil and dredged soil are extremely fine. Therefore, applying the solidification materials in Patent Documents 2 and 3 to the production of no-fired bricks using desert soil or dredged soil does not necessarily result in high-strength no-fired bricks.

[0009] For example, cement generally requires a certain curing period (e.g., more than one month) to solidify and develop its strength. This curing period is necessary for the hydration (redox reaction) of the remaining cement to continue even after some of the cement has solidified, due to the excess water remaining inside, leading to the solidification of the entire cement. In other words, cement is made by adding gypsum (2–3%) to clinker (clinker lump) obtained by firing raw materials (limestone, clay, silicate raw materials, iron oxide raw materials, etc.) in a kiln and grinding it. The clinker component (3CaO·Al2O3) reacts most rapidly with water, forming a fine crystalline coating of gypsum (CaSO4·2H2O) on the surface of the clinker component. This crystalline coating slows the hydration reaction rate of the clinker component. However, the hydration reaction of the cement proceeds more slowly through the crystalline coating, and calcium and other elements formed in the gaps between the cement particles accelerate the setting and hardening process.

[0010] Furthermore, in order to improve workability when filling and compressing the raw materials for bricks into a formwork, it is common to increase the fluidity by increasing the ratio of water to cement. This results in excess water being produced in excess of the amount required for the cement hydration reaction, and as this excess water seeps out onto the surface of the brick, tiny capillaries are formed inside the brick, which is thought to be the cause of a deterioration in the strength of the brick.

[0011] A first problem to be solved by the present invention is to provide a solidifying agent for unfired bricks that can improve the strength of unfired bricks that contain desert soil or dredged soil as a raw material. A second object of the present invention is to provide a method for producing high-strength non-fired bricks containing desert soil or dredged soil as raw materials, using the solidifying agent for non-fired bricks of the present invention. The third object of the present invention is to provide a manual manufacturing device for producing high-strength unfired bricks containing desert soil or dredged soil as raw materials, even in areas where it is difficult to obtain electricity, in addition to the second object of the present invention. [Means for solving the problem]

[0012] In order to solve the first problem, the inventors of the present invention investigated solidifying materials for no-fired bricks that contain desert soil or dredged soil as raw materials, based on the hypothesis that if they could promote the progress of the cement hydration reaction using excess water and modify the solidified crystals produced by the cement hydration reaction into a dense and strong crystallized structure, it would be possible to produce no-fired bricks that have strength suitable for construction structures, even if desert soil or dredged soil is included as a raw material.

[0013] First, given that excess water from cement hydration is alkaline, we conducted experiments to determine whether reacting alkaline excess water with a specific inorganic solidifying agent to produce solidified crystals would create adhesion between the brick's raw materials and the cement, resulting in the formation of strong, unfired bricks. As a result, we found that the strength of unfired bricks could be improved by mixing cement with an inorganic solidifying agent containing silicon dioxide, granular calcium chloride, and aluminum oxide (alumina) as essential components. Furthermore, we found that adding at least one inorganic solidifying agent selected from magnesium oxide, magnesium chloride, calcium hydroxide, and potassium chloride as a secondary component to these essential components is preferable. We found that these secondary components improve the fluidity of the mixture of brick's raw materials, cement, and water, improving workability when the mixture is filled into a formwork and compressed, as well as speeding up the solidification process.

[0014] In other words, the solidification material for non-fired bricks containing the desert soil or dredged soil of the present invention as a raw material can produce high-strength non-fired bricks by using, in addition to cement, inorganic solidification materials consisting of silicon dioxide, calcium chloride (granular), and aluminum oxide (alumina) as essential components.

[0015] It has been discovered that the essential components of the inorganic solidification agent of the present invention have the following solidification effects in cement solidification, as shown in Table 1. First, silicon dioxide reacts with excess alkaline water to produce solidified crystals, which create adhesive strength between the brick raw materials and cement, thereby contributing to improving the strength of unfired bricks. However, if the silicon dioxide content is too high, there is a concern that the strength improvement will be reduced. Furthermore, aluminum oxide has the effect of modifying the solidified crystals of the reaction product into a dense and strong crystallized structure. However, it has been discovered that if the aluminum oxide content is low, it is difficult to densify the crystallized structure, while if it is too high, the solidification rate decreases. Furthermore, calcium chloride (e.g., granular) reacts with other inorganic components, silicon dioxide and aluminum oxide, to form oxychloride cement, which has the function of strengthening the structure of the solidified crystals. However, if the calcium chloride content is low, it does not exhibit the effect of accelerating the solidification and crystallization time, while if it is high, the setting time is shortened. However, it has been found that the blending ratio of calcium chloride does not pose any particular problem in the production of non-fired bricks.

[0016] [Table 1]

[0017] Based on these findings, the method for producing unfired bricks containing desert soil or dredged soil as a raw material of the present invention is characterized by using the solidifying agent for unfired bricks of the present invention and producing unfired bricks having strength suitable for building structures by the following procedure. (Preparation step) Cement and at least the essential components of the inorganic solidification material shown in Table 1 are mixed in set ratios to prepare a solidification material mixture of the present invention in advance. (Step 1) The raw material of desert soil or dredged soil is mixed with aggregate sand in a set ratio. (Step 2) The mixture from step 1 is mixed with the solidifying agent of the present invention, and water is further added and kneaded. (Step 3) The mixture from step 2 is filled into a formwork and pressed at a set pressure to form green bricks. (Step 4) The formed raw bricks are removed from the formwork and allowed to dry naturally.

[0018] According to the manufacturing method of the present invention, the essential components of the inorganic solidification material of the present invention act to improve the strength of the unfired bricks during the cement hydration reaction, with silicon dioxide contributing to the enhancement of the strength of the unfired bricks, aluminum oxide modifying the solidified crystals into a dense and strong crystalline structure, and calcium chloride reacting with other essential components to form oxychloride cement, strengthening the structure. This allows for the production of strong unfired bricks using desert soil or dredged soil. Furthermore, it is desirable that the pressurization to the set pressure in step 3 be increased within a set short period of time.

[0019] Furthermore, in the preparation step, it is desirable to mix one or more of the inorganic solidification materials shown in Table 1 as auxiliary components in addition to the essential inorganic solidification material. That is, the auxiliary inorganic solidification material may include at least one of magnesium oxide, magnesium chloride, calcium hydroxide, and potassium chloride. These components contribute to improving adhesive strength and fluidity before hardening, as well as accelerating the hardening rate. However, it is preferable that the blending ratio of these components be lower than that of the essential components. It has been found that these auxiliary components not only further contribute to improving adhesive strength, but also contribute to accelerating the cement bonding reaction. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a solidifying agent for unfired bricks that can improve the strength of unfired bricks containing desert soil or dredged soil as a raw material. It is also possible to provide a method for producing high-strength unfired bricks containing desert soil or dredged soil as a raw material using the solidifying agent for unfired bricks of the present invention. Furthermore, it is also possible to provide a manual manufacturing device for producing high-strength unfired bricks containing desert soil or dredged soil as a raw material, even in areas where electricity is difficult to obtain. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a flowchart showing the steps of a method for producing non-fired bricks using desert soil or dredged soil according to one embodiment of the present invention. [Figure 2] FIG. 2 is a front view of a manual non-fired brick manufacturing apparatus according to one embodiment of the present invention. [Figure 3] FIG. 3 is a view of the non-fired brick manufacturing apparatus of FIG. 2 taken along the line II-II. [Figure 4] FIG. 4 is a view of the non-fired brick manufacturing apparatus of FIG. 3 taken along the line III-III. [Figure 5] FIG. 5 is a diagram illustrating the operation of the non-fired brick manufacturing apparatus of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] FIG. 1 shows a flowchart of a method for manufacturing unfired bricks containing desert soil or dredged soil as a raw material according to one embodiment of the present invention. First, in a preliminary preparation step (step S0), the solidifying material according to the present invention is prepared by uniformly mixing cement and an inorganic solidifying material and packaging it in a container or bag. The blending ratios of the cement, the inorganic solidifying material, and its essential and secondary components are determined in advance. In other words, to vary the blending ratio of the solidifying material depending on the characteristics of the raw material desert soil or dredged soil, tests are conducted in advance to determine the blending ratios based on the characteristics of the desert soil or dredged soil to be used. For example, since the moisture and salt content differ depending on the desert soil or dredged soil, the moisture and inorganic solidifying material blending ratios during mixing are adjusted to suit these characteristics. It has been shown that the time required for strength to develop is shorter when the raw material has a high salt content.

[0023] In addition, when determining the blending ratios of the essential and secondary components of the cement and inorganic solidification material, preliminary tests are conducted to provisionally set blending ratios of sand, cement, the solidification material of the present invention, and water for the desert soil or dredged soil that will actually be used, and multiple samples of unfired bricks are manufactured for each blending ratio. Strength tests are then conducted on these multiple samples to determine the optimal blending ratio for each desert soil or dredged soil that will actually be used. Examples of blending ratios obtained from the tests are shown in Table 2.

[0024] In Table 2, Example A shows the blending ratio of the composition of unfired bricks made from dredged soil, while Example B shows the blending ratio of the composition of unfired bricks made from desert soil. Note that both Examples A and B show the ratio in parts by mass, based on the mass (e.g., 4.4 kg) corresponding to four standard-sized unfired bricks. However, it goes without saying that the same ratio of parts by mass can be applied regardless of the number of standard-sized unfired bricks.

[0025] [Table 2]

[0026] After the preliminary test preparations described above, the solidification material preparation step (step S0) and steps S1 to S5 shown in Figure 1 are performed to produce unfired bricks. First, in the solidification material preparation step (step S0), as shown in Examples A and B in Table 2, 2 parts by mass of cement is mixed with 0.02 parts by mass of an inorganic solidification material consisting of essential and secondary components. In other words, the cement to inorganic solidification material ratio is 100:1 by mass. Because both the cement and the inorganic solidification material are powders, the process of mixing them uniformly at 100:1 takes a long time. Therefore, in this example, a cement with a high mixing ratio is divided into multiple portions and mixed with an inorganic solidification material with a low mixing ratio. That is, 2 kg of cement is divided into small portions, and 0.002 kg of the inorganic solidification material is mixed into one of the small portions. Next, another small portion of cement is added to this mixture and mixed. By dividing and repeating the mixing operation in this way, a uniform mixture of solidifying materials can be obtained at the desired ratio.In this example, 2 kg of cement was divided into two halves, and 0.002 kg of inorganic solidifying material was mixed with 1 kg of cement in one half, and the other 1 kg of cement was added to this mixture and mixed to obtain a uniform mixture of solidifying materials with a mass ratio of 100:1.

[0027] Next, steps S1 to S5, which are the essential steps of the method for producing unfired bricks using desert soil or dredged soil, are carried out. In step S1, sand is mixed with the raw material desert soil or dredged soil. The raw materials and sand are weighed out according to the blending ratio of Example A or Example B shown in Table 2, and mixed using a mixer or similar. Here, relatively high-quality sand such as mountain sand or river sand is preferred.

[0028] In step S2, water is added to the mixture of raw materials and sand while mixing with the solidifying agent prepared in step S0. The water content is, for example, 60 to 65% by mass, but this needs to be adjusted depending on the moisture content of the raw materials (dredged soil or desert soil). The moisture content can be adjusted by measuring the moisture content during mixing. In step S3, the mixture from step S3 is filled into a brick formwork and molded. When filling of the mixture into the formwork is completed in step 3, the process proceeds to step 4.

[0029] In step S4, a set pressure is quickly applied to the filler in the formwork to pressure-mold the bricks. This pressure-mold can be easily performed, for example, by making one of the frame plates constituting the rectangular parallelepiped formwork movable and providing a pressure mechanism that applies a set pressure to the movable frame plate. For example, the set pressure is the total pressure applied to one brick (for example, 3 tons). A short pressure increase time is preferable for improving the strength of the bricks. In other words, the pressure-receiving area S (for example, 11 cm x 23 cm = 253 cm) of the rectangular parallelepiped brick in the compression direction is 2 ) unit area (1cm 2 The pressure is increased (5.5 to 6.0 kg / sec) to 11 to 12 kg per 1000 sq. m in a short time of 1 to 2 seconds. This allows the drying time after molding to be shortened (for example, to a minimum of 3 days).

[0030] Step S5 begins after the pressure increase in step S4 is complete. The formed bricks (green bricks) are removed from the formwork, and the process proceeds to step S5 where they are dried. This removal can be performed by removing the formwork or by pushing out the green bricks from within the formwork. The drying in step S5 is performed by natural drying. For example, the green bricks are lined up at intervals in a roofed building and dried by natural ventilation. This drying period varies depending on the weather, but natural drying and hardening can be carried out for about 1 to 2 weeks while spraying water, to obtain unfired bricks with the required strength.

[0031] As described above, according to the method for producing unfired bricks of this embodiment, which contains desert soil or dredged soil as a raw material, the solidifying material for unfired bricks of the present invention is produced by adding water to desert soil or dredged soil and sand and kneading them. Therefore, even if desert soil or dredged soil is used as a raw material, the action of the solidifying material makes it possible to produce unfired bricks with strength suitable for construction structures.

[0032] The solidification effect of cement and inorganic solidification materials on desert soil or dredged soil has been previously described. However, it is expected that the optimal blend ratio of cement and inorganic solidification materials (essential and secondary components) will change depending on the characteristics of the desert soil or dredged soil used. Therefore, it is necessary to adjust the blend ratio of cement and inorganic solidification materials (essential and secondary components) to match the characteristics of the raw material desert soil or dredged soil. To achieve this, it is essential to adjust the blend ratio of raw materials, sand, cement, and inorganic solidification materials through prior testing to determine the optimal blend ratio based on the characteristics of the desert soil or dredged soil used. Similarly, it is also necessary to adjust the ratio of essential and secondary components of the inorganic solidification material. For example, since the moisture and salt content vary depending on the desert soil or dredged soil, the blend ratio of moisture and inorganic solidification materials during mixing must be adjusted to match these characteristics.

[0033] 2 to 4 show one embodiment of a manual-type manufacturing device for no-fired bricks using desert soil or dredged soil according to the present invention. This embodiment aims to provide a manual-type no-fired brick manufacturing device that can be installed near the site where the raw brick material is extracted. In other words, areas where desert soil or dredged soil is available generally lack sufficient infrastructure, such as power supplies. On the other hand, areas with abundant power supplies are generally located far from the desert soil or dredged soil extraction sites. Therefore, if a no-fired brick manufacturing plant is located far from the desert soil or dredged soil extraction site, the desert soil or dredged soil must be transported from the extraction site to the remote factory. In this regard, the manual-type manufacturing device can be installed in any area adjacent to the desert soil or dredged soil extraction site.

[0034] A manual manufacturing device for unfired bricks according to this embodiment will be described with reference to Fig. 2. As shown in the figure, a workbench 1 is formed using, for example, four pillars 1a, and a formwork 2 having a rectangular cylindrical cross section is supported at the center of the top of the workbench 1. The formwork 2 is formed by joining four plate materials into a rectangular cylindrical shape, and is supported with its cylindrical upper opening 2a positioned on a work surface 1b, which is the conceptual top of the workbench 1, and its cylindrical axis perpendicular to the work surface 1b. A lid 3 is disposed in contact with the upper opening 2a of the formwork 2. The formwork lid 3 is formed of a rectangular flat plate with a rectangular opening 3a corresponding to the upper opening 2a of the formwork 2 and a lid portion 3b covering the upper opening 2a, arranged in a longitudinal direction.

[0035] The mold cover 3 has both longitudinal edges inserted into guide grooves 5 formed in a pair of slide rails 4. Each of the pair of slide rails 4 is formed with a pair of support plate members 4a extending longitudinally and perpendicular to the work surface 1b, and a pair of guide plates 4b, 4c fixed at intervals above and below the opposing surfaces of the pair of support plate members 4a. In other words, the mold cover 3 is guided by the slide rails 4 and moved longitudinally while sliding along the surface of the upper end opening 2a of the formwork 2 and the work surface 1b, so that the rectangular opening 3a and cover portion 3b of the mold cover 3 can be selectively aligned with the upper end opening 2a of the formwork 2.

[0036] A pressure plate 6 having a rectangular cross section corresponding to the cross section of the rectangular cylindrical formwork 2 is inserted into the lower end opening 2b of the formwork 2. The pressure plate 6 is formed so as to be able to move up and down freely within the rectangular cylindrical formwork along the cylindrical axis of the formwork 2. A guide tube 7 is fixed to hang down from the center of the underside of the pressure plate 6. The tip of a piston rod 8a of a hydraulic cylinder 8 supported by the workbench 1 is inserted into the cylindrical opening at the lower end of the guide tube 7 and is able to slide freely within the cylinder. When extended, the tip of the piston rod 8a abuts against the underside of the pressure plate 6, and the pressure of the hydraulic cylinder 8 is raised within the rectangular cylindrical formwork 2 as the pressure in the hydraulic cylinder 8 increases.

[0037] Although not shown, the hydraulic cylinder 8 is connected to a hand-operated (manual) hydraulic pump that supplies hydraulic oil. The hydraulic cylinder 8 is supported on the workbench 1 via a fixed beam 9. A plurality of guide pipes 10 are fixed vertically to the fixed beam 9. A plurality of fixed pipes 11a are fixed to hang down from the underside of the pressure plate 6 at positions corresponding to the guide pipes 10. A sliding pipe 11 is inserted and fixed into each fixed pipe 11a. The sliding pipes 11 are inserted into the guide pipes 10 fixed to the fixed beam 9 so that they can slide freely. As a result, the pressure plate 6 rises and falls within the rectangular cylindrical shape along the cylindrical axis of the formwork 2 in response to the extension and contraction of the piston rod 8a of the hydraulic cylinder 8.

[0038] The tip of a brick discharge lever 13 is connected via a pin 12 to the cylindrical wall of the guide tube 7, which is fixed to and hangs down from the pressure plate 6. The other end of the brick discharge lever 13 serves as the lever operating end 13a, and its middle portion is provided in contact with the outer circumferential surface of a rolling wheel 14, which is supported on the workbench 1. In other words, the brick discharge lever 13 is provided so as to be swingable in a vertical plane, with the rolling wheel 14 as a fulcrum. As a result, by swinging the brick discharge lever 13 around the rolling wheel 14 as a fulcrum, as shown by arrow 19, the guide tube 7 can be raised and lowered via the pin 12, which raises the pressure plate 6 and pushes the compressed green bricks to the top of the formwork 2.

[0039] In this embodiment, the dimensions of the rectangular cross section of the pressure plate 6 are smaller than the dimensions of the rectangular cylindrical cross section of the formwork 2 by a set amount (e.g., 1 to 2 mm). This is to ensure a certain gap between the inner wall surface of the formwork 2 and the outer surface of the pressure plate 6. The purpose of ensuring this gap is to avoid problems such as wear or friction between the inner wall surface of the formwork 2 and the outer surface of the pressure plate 6 when the pressure plate 6 is raised and lowered. However, if such a gap is provided, there is a risk that soil and sand, the raw material for the bricks, will enter and become trapped in the gap between the inner wall surface of the formwork 2 and the outer surface of the pressure plate 6 during compression molding of the bricks, hindering smooth compression of the bricks. Therefore, in this embodiment, to prevent soil and sand, the raw material for the bricks, from becoming trapped in the gap between the inner wall surface of the formwork 2 and the outer surface of the pressure plate 6, a resin plate 17 (e.g., 2 mm thick PET, PC, etc.) with rectangular dimensions corresponding to the inner dimensions of the rectangular cylindrical formwork 2 is placed on the top surface of the pressure plate 6 to mold the bricks. The rectangular resin plate 17 can be used as an auxiliary conveying plate when conveying the green bricks after molding, and therefore can prevent damage to the green bricks before drying.

[0040] On the other hand, a lower opening 15a of a raw material hopper 15 that stores raw materials for bricks is connected to the rectangular opening 3a of the form lid 3. The form lid 3 is formed so as to be slidable along the slide rails 4 between a first position (see FIG. 5(c)) where the upper opening 2a of the form 2 is opened, a second position (see FIG. 5(a)) where the rectangular opening 3a is aligned with the upper opening 2a of the form 2, and a third position (see FIG. 5(b)) where the upper opening 2a of the form 2 is closed.

[0041] Furthermore, in this embodiment, the mold lid 3 has a pair of reinforcing plates 16a, 16b fixed vertically along a pair of opening edges in a direction perpendicular to the slide rail 4 of the upper end opening 2a of the formwork 2 when the formwork 2 is in the third position where the upper end opening 2a is closed. These reinforcing plates 16a, 16b can prevent deformation of the mold lid 3 due to the pressure applied to the mold lid 3 during compression molding of the bricks. In other words, when the pressure plate 6 is raised by the hydraulic cylinder 8 to compress the raw brick material, the pressure applied to the mold lid 3 can reach, for example, approximately 3 tons or more, so the reinforcing plates 16a, 16b increase the pressure resistance of the mold lid 3 to suppress deformation of the mold lid 3.

[0042] The operation of manufacturing unfired bricks using the manual unfired brick manufacturing device of this embodiment configured as described above will be described below. First, the mold cover 3 is moved along the slide rail 4, and the cover portion 3b of the mold cover 3 is disengaged from the mold 2 to completely open the upper end opening 2a. This is the initial position (FIG. 5(c)). However, unlike FIG. 5(c), the initial state of the hydraulic cylinder 8 is assumed to be one in which the piston rod 8a is lowered and held at the lower end position (e.g., the lowest end set). In other words, the initial state is one in which the hydraulic oil in the hydraulic cylinder 8 is discharged, for example, to a tank. In this initial state, the pressure plate 6 in the mold 2 is positioned at the lowest end, and a rectangular cylindrical space 16 is formed within the mold 2.

[0043] To begin the production of unfired bricks, desert soil or dredged soil, sand, and the solidification agent of the present invention are added according to the blending ratios of Examples A and B in Table 2, following the flow chart in Figure 1. Water is then added and mixed to produce a brick material mixture, which is then poured into the raw material hopper 15. Next, the mold cover 3 is moved from the first position (Figure 5(c)) along the slide rail 4 to the second position (Figure 5(a)), where the rectangular opening 3a of the mold cover 3 is aligned with the upper opening 2a of the formwork 2. Accordingly, the raw material hopper 15 moves, and the brick material mixture falls into the space 16 of the formwork 2 from the lower opening 15a of the raw material hopper 15, which is connected to the rectangular opening 3a of the mold cover 3.

[0044] With the formwork 2 filled with the brick material mixture, the form cover 3 is moved along the slide rail 4 and advanced to the third position (FIG. 5(b)) where the cover part 3b closes the rectangular opening 2a of the formwork 2. This closes the bottom opening 15a of the raw material hopper 15, cutting off the supply of the brick material mixture, and the brick material mixture in the formwork 2 is sandwiched between the pressure plate 6 and the form cover 3.

[0045] In this state, a manual hydraulic pump is operated to supply hydraulic oil to the hydraulic cylinder 8. This causes the piston rod 8a to extend and the pressure plate 6 to rise, compressing the raw brick material that has been placed in the space 16 within the formwork 2. At this time, hydraulic oil is supplied to the hydraulic cylinder 8 so that the pressure applied to the raw brick material via the pressure plate 6 becomes a set pressure (for example, a total pressure of 3 tons). When the hydraulic pressure in the hydraulic cylinder 8 reaches the set hydraulic pressure, a hydraulic relief valve (not shown) is opened to maintain the set hydraulic pressure. In this way, when the set hydraulic pressure is applied to the raw brick material, the extension of the piston rod 8a stops, and a rectangular parallelepiped green brick 18 of the specified dimensions is pressure-molded.

[0046] After confirming that the pressing of the raw bricks has been completed, the mold cover 3 is returned to the first position (Fig. 5(c)). This opens the rectangular opening 2a of the formwork 2. Next, when the operating end 13a of the brick discharge lever 13 is pressed down, the brick discharge lever 13 swings around the rolling wheel 14 as a fulcrum, and the guide tube 7 connected to the tip of the lever via the pin 12 is pushed up. This pushes up the upper surface of the pressure plate 6 via the guide tube 7 to the position of the work surface 1b, thereby pushing up the raw bricks 18 to the position of the work surface 1b.

[0047] Next, when the mold cover 3 is moved in the direction of the second position ((a) in FIG. 5), the reinforcing plate 16a located on the opposite side of the raw material hopper 15 comes into contact with the formed green bricks 18. As a result, the green bricks 18 slide on the work surface 1b while still resting on the resin plate 17, and can be pushed out from the work table 1 to a transport means such as a transport cart (not shown).

[0048] The raw bricks pushed onto the conveying means have not yet dried or hardened, so they are moved to a drying area while still on the conveying means and dried. The drying area for raw bricks is a space with a roof but no walls. In the drying area, the raw bricks are dried and hardened while being sprayed with water for about two weeks, becoming unfired bricks.

[0049] As described above, the manual unfired brick manufacturing device of this embodiment can manufacture unfired bricks without using electricity by driving the hydraulic cylinder 8 with a manual hydraulic pump. Therefore, the manual manufacturing device of this embodiment can be installed near a site where desert soil or dredged soil is collected, and unfired bricks can be manufactured, eliminating the need to transport the collected desert soil or dredged soil to a distant unfired brick manufacturing plant or the like.

[0050] The present invention has been described above based on embodiments, but it is obvious to those skilled in the art that the present invention is not limited to these embodiments and can be implemented in modified or altered forms within the scope of the gist of the present invention, and it goes without saying that such modified or altered forms fall within the scope of the claims of this application.

Claims

1. A method for producing unfired bricks containing desert soil or dredged soil as a raw material, comprising: A preparation step of dividing cement into a first portion and a second portion, mixing the first portion of cement with an inorganic solidifying material containing silicon oxide, calcium chloride, and aluminum oxide as essential components, and adding the second portion of cement to the resulting mixture and mixing them to obtain a solidifying material; a raw material mixing step of mixing the desert soil or the dredged soil with sand to obtain a raw material mixture; a kneading step of mixing the raw material mixture and the solidifying agent, adding water, and kneading the mixture to obtain a kneaded product; a molding step of filling the kneaded material into a formwork and pressurizing it at a set pressure to form green bricks; a drying step in which the formed green brick is removed from the formwork and allowed to dry naturally; A manufacturing method comprising:

2. The pressurizing method in the molding step is a method in which the total pressure per raw brick is 3 tons, and the pressure is increased to 11 to 12 kg / cm2 per unit area of ​​the pressure-receiving area in 1 to 2 seconds. The method of claim 1.

3. In the mixing step, when the desert soil or the dredged soil is 12 parts by mass, the sand is mixed in the range of 0.9 to 1.1 parts by mass, the cement is mixed in the range of 1.8 to 2.2 parts by mass, the inorganic solidification material is mixed in the range of 0.0018 to 0.0022 parts by mass, and the water is mixed in the range of 2.34 to 2.86 parts by mass. The method of claim 1.

4. The inorganic solidification material contains at least one accessory component selected from magnesium oxide, magnesium chloride, calcium hydroxide, and potassium chloride. The method of claim 1.

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