JP2006248896A - Method for manufacturing cao-mgo-sio2-based solidified article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase bending strength of a SiO<SB>2</SB>-CaO-based solidified article. <P>SOLUTION: The solidified substance is an article solidified with an autoclave treatment which contains a CaO-based substance, a MgO-based substance and a SiO<SB>2</SB>-based substance. The CaO-MgO-SiO<SB>2</SB>-based solidified substance is characterized in that when the total content by weight of the three ingredients consisting of CaO, MgO and SiO<SB>2</SB>in a raw material to be solidified is 100%, the ratio by weight of CaO in the total content of 100% is C%, and the ratio by weight of MgO is M%, (C+M) is 3.7-50%, and the ratio of C/(C+M) is 0.3 or more. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a CaO—MgO—SiO ₂ solidified body, and particularly to a CaO—MgO—SiO ₂ solidified body having high strength.

A solidified body can be obtained by mixing a CaO-based material such as CaO or Ca (OH) _{2 with} an SiO ₂ -based material such as silica sand and subjecting it to autoclaving.

The object of the present invention is to increase the bending strength of the SiO ₂ —CaO-based solidified body.

The CaO—MgO—SiO ₂ solidified body of the present invention is a solidified body obtained by solidifying a mixture containing a CaO based material, an MgO based material, and a SiO ₂ based material by autoclaving. When the total weight content of the three of CaO, MgO and SiO ₂ is 100%, the weight ratio of CaO in the total 100% of these three is C%, and the weight ratio of MgO is M%. (C + M) is 3.7 to 50%, and the C / (C + M) ratio is 0.3 or more.

The present invention has been completed by finding that the strength of the solidified body, in particular the bending strength, is increased by replacing a part of the CaO content of the SiO ₂ —CaO-based solidified body with MgO.

The CaO—MgO—SiO ₂ solidified product of the present invention is obtained by substituting a part of CaO in the SiO ₂ —CaO autoclaved solidified product with MgO, and in this way, high bending strength can be obtained. Can do.

In the present invention, as the SiO ₂ -based material, amorphous SiO ₂ , crystalline SiO ₂ , silica sand, glitter fine sand, diatomaceous earth, clay, feldspar, silica fume, white carbon, tile waste, glass waste , Brick scrap, slag, cement / concrete waste, coal ash, sludge, waste sludge, sludge incineration ash, industrial waste after extraction of Ca (eg cement / concrete waste, slag, waste sludge, coal ash, sludge incineration ash 1 type or 2 types or more can be used. By reacting these SiO ₂ -based materials with CaO and / or MgO-based materials, (CaO and / or MgO) -SiO ₂ -H ₂ O-based solid materials are efficiently generated in the obtained solidified body. The strength of the solidified body can be increased.

As the CaO-based material and MgO-based material, one or more of CaO, Ca (OH) ₂ , MgO, Mg (OH) ₂ , slag, and concrete waste materials are used. Among these, CaO and Ca (OH) ₂ are preferable as the CaO-based material, and Mg (OH) ₂ is preferable as the MgO-based material. In addition, slag and concrete waste materials also act as SiO ₂ -based materials.

The total content (weight) of the three of CaO, MgO, and SiO _{2 in} the solidified raw material is 100%, and the weight ratio of CaO, MgO, and SiO ₂ in the total of 100% of these three is C%, M% , S% (C + M + S = 100).

  In the present invention, the sum of C and M (C + M) and the ratio C / (C + M) of C and (C + M) are as follows.

  (C + M) is 3.7 to 50%, preferably 3.7 to 49%, then preferably 3.7 to 40%, and then preferably 3.7 to 35%, most preferably Is 3.7 to 15%.

  C / (C + M) is 0.3 or more, preferably 0.4 or more, then preferably 0.7 or more, and most preferably 0.8 to 0.995.

Since SiO ₂ -based materials are less expensive than CaO-based materials and MgO-based materials, it is preferable to increase the amount of SiO ₂ -based materials as much as possible.

In the present invention, materials other than SiO ₂ materials, CaO materials, and MgO materials may be included.

  In order to produce the solidified body of the present invention, the raw materials are mixed, formed into a desired shape by a molding method such as press molding, cast molding, extrusion molding, or casting, and then autoclaved. The solidified raw material may be subjected to autoclave treatment as it is without being molded, and may be molded and further autoclaved.

The autoclave treatment can be performed under a relatively mild condition of 100 to 250 ° C., particularly about 150 to 200 ° C. under a saturated vapor pressure (16 kgf / cm ² or less). Time, especially about 5 to 10 hours.

  The obtained solidified body is dried under appropriate conditions as required, and then used as various construction / civil engineering materials. This solidified body is particularly suitable for use as an interlocking block.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. In the following experiments, quartz or amorphous silica is used as the SiO ₂ material, a special grade CaCO ₃ calcined at 1000 ° C. for 5 hours is used as the CaO material, and a reagent is used as the MgO material. Primary Mg (OH) ₂ was used.

  Further, the bending strength of each sample was measured under the three-point bending strength measurement conditions with a span distance of 30 mm and a crosshead speed of 0.5 mm / min.

Raw materials were dry-mixed in a mortar with the composition shown in Tables 1 and ² , and pressure-molded at 300 kgf / cm ² to obtain a molded body of 40 mm × 10 mm × about 10 mm thickness.

  Each molded body was put in an autoclave and treated at 200 ° C. for 10 hours to be solidified. In addition, 300 cc of distilled water was put into an autoclave container (2000 cc capacity) and treated at a saturated vapor pressure.

After the obtained solidified body was dried at 60 ° C., the bending strength was measured and the results are shown in Tables 1 and 2. In addition, the SiO ₂ , CaO, and MgO composition ratio of each molded body is shown in FIG.

From Tables 1 and 2 and FIG. 1, the following is clear. That is, when (C + M) exceeds 50%, unreacted Ca (OH) ₂ and Mg (OH) ₂ increase and the strength decreases. Moreover, even if (C + M) is less than 3.7%, the strength is lowered. When C / (C + M) is smaller than 0.3, the strength is lowered.

In Tables 1 and 2, Nos. 1, 6, 11, 15, 22, 29, and 36 are not added with an MgO-based material. Nos. 1 to 5, 6 to 10, 11 to 14, 15 to 21, 22 to 28, 29 to 35, and 36 to 41 are series in which the molar ratio of (CaO + MgO) / CaO is made equal. In each series, the bending strength was higher than those of No. 1, 6, 11, 15, 22, 29, 36 to which MgO was not added, and those of 4.9 MPa or more were judged as ◯. The bending strength of 4.9 MPa is a value corresponding to 50 kgf / cm ² or more determined as a standard value of “ordinary interlocking block” by the Interlocking Block Association. For No. 27, the strength was lower than that of No. 22 due to the addition of MgO, but it was determined to be Δ because it was 5 MPa or more.

It is a composition diagram of SiO ₂ , CaO, and MgO.

Claims (5)

A solidified product obtained by solidifying a mixture containing a CaO-based material, a MgO-based material, and a SiO ₂ -based material by autoclaving, and having three weight contents of CaO, MgO, and SiO _{2 in} the solidified raw material When the total is 100%, the weight percentage of CaO in the total 100% of these three is C%, and the weight percentage of MgO is M%, (C + M) is 3.7 to 50%, C A CaO—MgO—SiO ₂ solidified body having a / (C + M) ratio of 0.3 or more. According to claim 1, (C + M) is 3.7~49%, C / (C + M) ratio CaO-MgO-SiO ₂ based solid material, characterized in that at least 0.4. _{2. The} CaO—MgO—SiO ₂ solidified body according to claim 1, wherein (C + M) is 3.7 to 40% and C / (C + M) ratio is 0.7 or more. _{2. The} CaO—MgO—SiO ₂ solidified body according to claim 1, wherein (C + M) is 3.7 to 35% and C / (C + M) ratio is 0.8 to 0.995. According to claim 1, (C + M) is 3.7~15%, C / (C + M) ratio CaO-MgO-SiO ₂ based solid material, characterized in that less than 0.3.

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