JPH02160652A - Production of hydraulic object consisting essentially of diatomaceous earth - Google Patents

Abstract

PURPOSE:To obtain a hydraulic substance body having a high strength using diatomaceous earth by adding an acid to a diatomaceous earth component, converting aluminum oxide therein into an aluminum salt, then neutralizing the resultant substance and adding cement thereto. CONSTITUTION:An acid is added to diatomaceous earth powder to convert aluminum oxide therein into an aluminum salt and an alkali is then added to neutralize the resultant substance. Cement is then added thereto. Portland cement-based, alumina cement, jet cement, mixed cement-based or high-sulfate slag cement-based cement, a mixture thereof, etc., are cited as the cement used. Slaked lime, calcium carbonate, a mixture thereof, etc., are cited as the alkali. The afore-mentioned diatomaceous earth powder-cement mixture can be molded into a required shape by extrusion molding. Hydrochloric acid, sulfuric acid or an optional acid capable of reacting in the form of an aqueous solution with alumina and producing an aluminum slat can be used as the acid. Nitric acid, etc., irritating operators are preferably avoided in selecting the acid.

Description

DETAILED DESCRIPTION OF THE INVENTION ■Object of the Invention (1) Field of Industrial Application This invention relates to a method for manufacturing hydraulic objects that effectively utilizes diatomaceous earth, which is present in large quantities throughout the country.

(2) Conventional technology Diatomaceous earth, which exists in large quantities all over the country, is a type of albite formed by the remains of diatoms deposited on the sea floor, and contains radioactive flux, lime grains, etc. in addition to diatoms. It is hydrated amorphous silica. However, although diatomaceous earth is currently used for things that lack strength, such as heat-insulating materials, no technology has been developed to use it for things that require strength, such as building materials, roofing materials, and tiles.

(3) Problems to be solved by the invention Therefore, it is possible to obtain a hydraulic material stronger than diatomaceous earth by using relatively inexpensive general-purpose cements such as Portland cement, mixed cement, and high sulfate slag cement. If possible, hydraulic objects could be provided at low cost, but,
When the above-mentioned general-purpose cement is added to diatomaceous earth and mixed with water, aluminum oxide in the diatomaceous earth becomes acicular crystals of ettringite 3CaO"At203"3CaSO4"nH2O and precipitates in large quantities in the hardened cement phase. The problem is that the cement phase collapses from within, significantly reducing the strength of the hydraulic object.

The present invention was made in view of the above conventional problems, and its purpose is to treat diatomaceous earth with acid to convert the alumina component contained therein into aluminum salt, and then to neutralize the pH of the entire composition. Therefore, by neutralizing the excess acid with alkali and mixing it with cement, we can suppress the formation of needle-shaped ettringite crystals in the phase of hydraulic molded products, and use diatomaceous earth to create strong hydraulic materials. The purpose is to provide a method of molding the material at low cost.

■ Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention involves adding an acid to diatomaceous earth powder to convert aluminum oxide in the diatomaceous earth component into an aluminum salt, and adding an alkali to this. This constitutes a method for producing a first hydraulic object by neutralizing and adding cement.

Further, the cement may be selected from Portland cement, alumina cement, jet cement, mixed cement, high sulfate slag cement, or a mixture thereof.

Alternatively, the alkali may be selected from slaked lime, calcium carbonate, or a mixture thereof.

It also includes a configuration in which the diatomaceous earth powder-cement mixture is molded into a desired shape by extrusion molding.

Next, an acid is added to the diatomaceous earth powder to convert the aluminum oxide in the diatomaceous earth component into an aluminum salt, and an alkali is added to neutralize this to produce a second hydraulic object that is mixed with cement and red mud. This constitutes a method.

Alternatively, an arrangement may be made in which acid is added to diatomaceous earth powder to convert aluminum oxide in the diatomaceous earth component into aluminum salt, which is neutralized by adding lime-containing red mud, and then cement is added.

Next, the red mud was treated with acid, diatomaceous earth powder was added, and the aluminum oxide in the diatomaceous earth powder was made into an aluminum salt by the acid contained in the red mud, and an alkali was added to neutralize it, and cement was added. This constitutes the method for manufacturing the third hydraulic object.

(2) According to chemical analysis, the composition of diatomaceous earth is silica (SiO□)6
0~70WT%, alumina (At203) 13~16W
T is dominant. Therefore, in the first method for producing a hydraulic object, acid is added to diatomaceous earth powder to convert alumina into a neutral aluminum salt.

As the acid, hydrochloric acid, sulfuric acid, or any acid that reacts with alumina in the form of an aqueous solution to form an aluminum salt can be used, but when selecting the acid, it is preferable to avoid nitric acid, etc., which can irritate the operator. Then, an alkali is added to neutralize the excess of the added acid and the pH of the entire composition is approximately neutral, and an appropriate amount of cement is added and kneaded with water to form a hydraulic object.

In addition, slaked lime, calcium carbonate, or a mixture thereof can be used as the alkali to neutralize the acid, but as with acids, it is preferable to avoid those with a pungent odor, and depending on the use of the cured product, Careful consideration should also be given to the use of carbonates which create bubbles of carbon dioxide gas within.

In addition, the cements used are alumina cement and all other general-purpose cements, such as Portland type, jet cement, mixed cement type, such as blast furnace cement, fly ash cement, and high sulfate slag cement type, such as water slag slag. Right-(slaked lime and portland cement) systems, etc. may also be used.

When molding, casting using a conventional frame or extrusion molding may be used. Next, in the second method for producing a hydraulic object, alkali and red mud are added to neutralize the entire composition, or red mud containing lime is added for neutralization.

Furthermore, in the third method for producing a hydraulic object, acid-treated red mud is added to diatomaceous earth powder to convert alumina into aluminum salt, which is then neutralized with an alkali.

(3) Examples Hereinafter, preferred embodiments of the present invention will be described.

Example (1) 40 cc of 98% sulfuric acid was added to 15 kg of diatomaceous earth dried and crushed into a powder of approximately 2000 cm2/g or more.

Add 800 cc of water and stir well, then add 1200 g of calcium hydroxide and stir. The pH after stirring was approximately 6.

In addition to this, 850g of Class 8 blast furnace cement (equal composition of water slag and Portland cement), 15g of calcium sulfate
When 0g is added and stirred, the pH becomes about 12, so fill it neatly, apply pressure to remove moisture, and leave it to harden at room temperature. For example, the bending failure load after forming into a thick slate tile and curing for 28 days was 180 kg f.

Example (2) Diatomaceous earth powder 1.5Kg, 98 thiosulfuric acid 20cc, water 800c
c was added and stirred well. The pH at this time was about 1. After adding 30g of slaked lime and adjusting the pH to about 8.5, 23g of Portland cement 1 180g of calcium sulfate
Add g and stir. The pH after stirring was approximately 9.

This is filled into a mold, pressurized to remove excess moisture, and left to harden at room temperature. The bending failure load after forming into a thick slate tile and curing for 28 days was 185 kgf.

Example (3) Diatom ±1.5 Kg, 35% hydrochloric acid 215cc, water 16
00cc, add 350g of calcium hydroxide and adjust the pH.
After stirring at 850 g'i, 850 g'i of blast furnace cement and 150 g of calcium sulfate were added to adjust the pH to 10 to 11, the mixture was filled into a mold, excess moisture was removed, and the mixture was left to harden at room temperature.

The bending failure load after forming into a thick slate tile and curing for 28 days was 180 kgf.

Example (4) The formulation of Example (1) was heated to a water content of 18% suitable for extrusion molding.
Dehydration is adjusted to wt%, a small amount of plasticizer such as methyl cellulose is added, extruded into a plate shape using an extruder, cut as appropriate, and left to harden at room temperature to produce tiles, pillars for building materials, roof tiles, etc. can manufacture interior and exterior materials. It is also possible to incorporate inorganic or organic reinforcing fibers.

Example (5) Acid-treated diatomaceous earth powder 27, water slag 40, stone bones 4, blast furnace cement 7, waste pulp 12, and asbestos 50 were dispersed in water to a slurry concentration of 5 g in a weight ratio, and appropriately processed using a paper making machine. Thick architectural interior and exterior pulp cement boards (JIS A3414
-1978 equivalent).

The bending failure load after curing for 28 days was 80. OK g(
6 mm in thickness) and 85.5 kg (12 mm in thickness).

Example (6) The composition shown in Example (3) was poured into a split mold for dolls and other molded products, left to harden at room temperature, taken out from the split mold, and heated for 28 hours.
After curing for a day, dry and paint.

A coloring agent may be mixed into the formulation and molded.

It is also possible to further pulverize the raw material of the above-mentioned formulation, add an appropriate amount of a water retention agent and a hardening retarder, and perform casting molding into the mud 1 using the right front mold.

Example 7 1.5Kg of diatomaceous earth powder, 40cc of 98% sulfuric acid, 80Oc of water
After adding c and stirring thoroughly, 52 g of calcium hydroxide was added and neutralized with stirring. The pH after neutralization is approximately 6. 8 to this
Seed blast furnace cement) 850 g, calcium sulfate 150 g
Then, 11 to 19 g of fine aluminum powder is added as a foaming agent, and after stirring, the mixture is poured into a mold for foam molding and cut into required dimensions to obtain a lightweight building material equivalent to ALC having a bulk specific gravity of 0.6 to 1.2.

Steam curing at normal pressure of 60C or autoclave high temperature and high pressure steam curing under a pressure of about 10 atm is suitable.

Example 8 150Kg of diatomaceous earth, 7.5Kg of 98% sulfuric acid, 8Kg of water
Add ゜0 liter and stir well to make slaked lime 5.7 Kg
After neutralization, 150 kg of Portland cement is added, and fl water is added to make a field hard kneading with a slump value of 5-6 cm.

This kneaded material is put into a centrifugal tube forming machine together with the assembled reinforcing bars, formed into a tube shape, and after first steam curing, it is demolded, and the second curing is carried out in water, with water spray, in air, or in an autoclave (10-15 atm, 8-16 m). Time) Curing and JIS A 5303
Obtain a considerable amount of Hume's canal.

It is also possible to obtain a rebar formed pipe equivalent to JIS A 5302 by mold forming, and a foundation pile equivalent to JIS A 5310 can also be obtained by manual force forming of the rebar and autoclave curing (10-15 atm, 8-16 hours). .

1. Detailed Description of the Invention As described above, the present invention, when mixing diatomaceous earth and cement to produce a hydraulic object, converts the aluminum oxide contained in the diatomaceous earth into aluminum salt by adding acid to the diatomaceous earth, The treatment is performed by adding an alkali to neutralize excess acid, and a suitable amount of acicular crystals of Etrin guide is generated in the hardened material. In addition, the surface of the crystalline phase contained in diatomaceous earth is activated by acid, and a fine, uniform structure is produced by a hydraulic reaction, making it possible to obtain a hydraulic object with remarkable strength. Taking thick slate tiles as an example, the minimum bending fracture strength according to JIS standards is clay tiles (JIS A 5208-19).
77), it is set as 120 kg f, and in the case of general cement tiles (JIS A 5401-1978), it is set as 1.
00Kg f, thick slate (JIS A 540
2-1976), it is determined to be 120Kgf, whereas the thick slate tiles according to the present invention show a value of almost 180-220Kg, f, and the surface alkali content is lower than that of general cement products. Because of its low carbon content, it is easy to select the paint to be used for this, and the raw materials to be used include diatomaceous earth, which has nearly infinite reserves and no effective use has been established, or diatomaceous earth, which has been disposed of in coastal landfills and is currently not effective. It uses raw materials such as red mud, for which no use has been found, and costs almost nothing other than collection costs and transportation costs, and requires almost no energy costs such as firing or other molding costs.
For example, by adjusting the moisture content, adding a small amount of plasticity, and extrusion molding, it can be made into a material equivalent to a fired viscosity tile (JIS A 5208-
1977), and provides superior quality products with far superior strength and finely smooth surfaces compared to conventional products made only of alumina cement and other cements. It can be used for roof tiles, building ceiling panels, interior and exterior construction materials, and all kinds of cement, concrete products, and non-fired ceramic products, and the specific gravity can be kept to a low value of around 1.9. Depending on the intended use, the weight can be further reduced by foaming the product or hollowing out a part of it.Also, if red mud is not used, it is light gray and can be mixed with pigments or painted to make almost any kind of product. It has excellent characteristics and effects in various aspects, such as being able to be colored freely.

Claims (1)

[Claims] 1. Diatomaceous earth as a main component, characterized in that an acid is added to diatomaceous earth powder to convert aluminum oxide in the diatomaceous earth component into an aluminum salt, which is neutralized by adding an alkali, and then cement is added. A method for manufacturing a hydraulic object. 2. The hydraulic body according to claim 1, characterized in that the cement is selected from Portland cement, alumina cement, jet cement, mixed cement, high sulfate slag cement, or mixtures thereof. Production method. 3. The method for producing a hydraulic object according to claim 1, wherein the alkali is selected from slaked lime, calcium carbonate, or a mixture thereof. 4. Claim 1, characterized in that the diatomaceous earth powder-cement mixture is formed into a desired shape by extrusion molding.
2. Method for producing a hydraulic object as described in Section 1. 5. Adding acid to diatomaceous earth powder to convert aluminum oxide in the diatomaceous earth component into aluminum salt, adding alkali to neutralize this, and mixing cement and red mud.
A method for producing a hydraulic object whose main component is diatomaceous earth. 6. Claim 5, characterized in that an acid is added to diatomaceous earth powder to convert aluminum oxide in the diatomaceous earth component into aluminum salt, which is neutralized by adding lime-containing red mud, and then cement is added. A method of manufacturing the hydraulic object described above. 7. Red mud is treated with acid, diatomaceous earth powder is added, aluminum oxide in the diatomaceous earth powder is made into an aluminum salt by the acid contained in the red mud, an alkali is added to neutralize this, and cement is added. A method for producing a hydraulic object whose main component is diatomaceous earth.