JPH0558704A - Composition for inorganic forming body - Google Patents

Abstract

PURPOSE:To offer a composition for an inorganic formed body possible to form the inorganic formed body having high mechanical strength and drastically useful for, e.g. building material and road material with available utilization of purified sludge by using a specific purification sludge obtained by calcination treating the purification sludge generated from a purification plant, possible to execute hardening reaction at a relatively low temp. for a short time with good caking ability and workability, possible to improve productivity of the inorganic formed body and possible to obtain the inorganic formed body in low cost. CONSTITUTION:The objective composition for the inorganic formed body consists of 100 pts.wt. granular calcined sludge having 5-150mum particle diameter and 50-150 pts.wt. alkali metal silicate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for an inorganic molded body, which is useful as, for example, a building material and a road material and can form an inorganic molded body in a short time.

[0002]

2. Description of the Related Art In general, an inorganic molded article is useful as a building material and a road material. Conventionally, for molding the inorganic molded article, an inorganic molded article prepared by mixing various inorganic solid components in an aqueous alkali metal silicate solution. Compositions were known.

[0003]

However, all of the conventional compositions for inorganic molded products have a problem that the manufacturing cost is high, and they are solidified at a relatively low temperature, have good moldability, and have a manufacturing workability. It has been desired to develop a composition for an inorganic molded body, which has good properties and can obtain an inorganic molded body having a high mechanical strength.

On the other hand, most of the purified water sludge generated from the water purification plant is landfilled as industrial waste.
In the past, effective use of purified water sludge has been attempted in various industrial fields.

In view of the above points, the inventor of the present invention has conducted extensive studies, and as a result, by using a specific purified water sludge that has been subjected to a calcination treatment and mixing it with an aqueous alkali metal silicate solution to cause a reaction, a high machine It was found that an inorganic molded body having a desired strength can be formed, and the present invention has been completed.

An object of the present invention is to use a specific purified water sludge that has been subjected to a calcination treatment to form an inorganic molded article having a high mechanical strength, which is extremely useful as, for example, a building material and a road material. The sludge can be effectively used, the moldability is good and the workability of the production is good, and the curing reaction can proceed at a relatively low temperature in a short time, improving the productivity of the inorganic molded body. Therefore, it is an object of the present invention to provide a composition for an inorganic molded body, which can be obtained and can be obtained at a low cost.

[0007]

In order to achieve the above object, the present invention provides 100 parts by weight of granular calcined sludge having a particle size of 5 to 150 μm and an aqueous alkali metal silicate solution 5
The gist is a composition for an inorganic molded body consisting of 0 to 150 parts by weight.

In the above, the calcined sludge is one obtained by calcining and pulverizing purified water sludge. Here, the purified water sludge, agglomeration products mainly clay, lime sludge generated by softening treatment of hard water, iron, inorganic sludge that has collected inorganic ions such as manganese,
Classified as organic sludge such as plankton algae and activated carbon adsorption waste. Among them, the majority occupy the agglomerated product mainly composed of clay.

Agglomerated products mainly composed of clay are generated as settled sludge, rapid filter basin washing wastewater, and slow filter basin washing sand drainage. These substances also contain a certain amount of components of organic sludge such as inorganic sludge in which inorganic ions such as iron and manganese are collected, plankton algae, activated carbon adsorbed waste, and the like.

Aluminum sulfate and aluminum chloride are generally used as the coagulant. The aluminum salt used as the coagulant is Al (OH) 2 after the coagulation reaction.
It becomes ₃ and precipitates, forming sludge.

The composition of the purified water sludge is Al ₂ O ₃
Is 10 to 40%, SiO ₂ is 10 to 50%, and a small amount of Fe ₂ O ₃ , MnO, CaO, etc. is contained. Al ₂ O
₃ is added as a coagulant and contained in clay particles.

Further, SiO ₂ is contained in the clay particles.

These purified water sludges are burned and crushed before use, and the burning temperature is 300 to 1000 ° C., preferably 40.
It is 0-600 degreeC.

If the calcination temperature of the purified water sludge is less than 300 ° C., the calcined sludge does not have sufficient reaction activity, the reaction with the alkali metal silicate aqueous solution is insufficient, and high mechanical strength is obtained. It is not preferable because it does not exist. Further, even when the firing temperature exceeds 1000 ° C., the fired sludge does not have sufficient reaction activity, the reaction is insufficient, and high mechanical strength cannot be obtained, which is not preferable.

The particle size of the calcined sludge is preferably 5 to 150 μm.

When the particle size of the calcined sludge is less than 5 μm, the viscosity of the mixture of the calcined sludge and the aqueous solution of alkali metal silicate is too high, and sufficient kneading cannot be achieved.
Not preferable. Further, if the particle size of the calcined sludge exceeds 150 μm, the time required for curing becomes long and the strength also decreases, which is not preferable.

As the alkali metal silicate aqueous solution, an aqueous solution of potassium silicate or sodium silicate or a mixture thereof is used.

The composition of such an aqueous solution is SiO ₂ and K
₂ O, SiO ₂ and Na ₂ O, or SiO ₂ and K ₂ O +
Na ₂ O having a molar ratio of 1.0 to 3.0
And the concentration of the aqueous solution is preferably in the range of 30 to 60%.

The composition ratio of the inorganic molding composition of the present invention is 100 in the form of granular burned sludge having a particle size of 5 to 150 μm.
50 to 150 parts by weight of alkali metal silicate aqueous solution
Parts by weight.

When the amount of the alkali metal silicate aqueous solution is less than 50 parts by weight based on 100 parts by weight of the above-mentioned calcined sludge,
Since the amount of liquid is small, sufficient kneading cannot be performed, and molding is not easy, which is not preferable. On the other hand, if the amount of the alkali metal silicate aqueous solution exceeds 150 parts by weight, the reaction is not sufficiently solidified and high strength cannot be obtained, which is not preferable.

The composition for inorganic molded articles according to the present invention comprises:
A filler can be blended depending on the required physical properties of the obtained inorganic molded article and its use.

The mixing ratio of the filler is 100% of the above-mentioned calcined sludge.
It is 5 to 200 parts by weight with respect to parts by weight.

Here, if the amount of the filler is less than 5 parts by weight, the strength is not sufficient, which is not preferable. In addition, the filler is 200
If the amount is more than parts by weight, the amount of the alkali metal silicate aqueous solution is relatively small, so that sufficient kneading cannot be performed and molding is not easy, which is not preferable.

Examples of such fillers include pulverized or finely divided inorganic substances such as rock powder, basalt, mica,
It is possible to use silica sand, glass powder, clay such as alumina, aluminum hydroxide, talc, calcium carbonate, kaolin, fiber materials, and various other inert or water-insoluble minerals. These fillers are appropriately selected according to the use of the inorganic molded body, and are used alone or as a mixture.

In the present invention, in addition to the calcined sludge, the alkali metal silicate aqueous solution, and the filler, if necessary, a curing accelerator, a pigment, and other additives can be added in appropriate amounts.

From the composition for inorganic moldings according to the present invention,
In order to manufacture an inorganic molded body, first, purified water sludge generated from a water purification plant is fired at a temperature of 300 to 1000 ° C., and then,
Grind to a particle size of 5-150 μm with a grinder. Then, a granular calcined sludge, which is a solid component in the composition thus obtained, is mixed with a filler and the like at a predetermined ratio, if necessary, and then mixed with an alkali metal which is a liquid component. Add an aqueous silicate solution and knead until the solid components are sufficiently dispersed.

The thus obtained raw material kneaded material for an inorganic molded body is given a shape when the kneaded material has an appropriate hardness, and when the kneaded material is soft, it is poured into a predetermined mold to give 50 to 1
By heating at a temperature up to 00 ° C. for 1 to 4 hours, an inorganic molded body having a predetermined shape is formed.

[0028]

According to the above-mentioned composition for an inorganic molded body, granular calcined sludge, an aqueous solution of an alkali metal silicate and, if necessary, a filler and the like are mixed, and after being shaped, they are calcined by heating appropriately. The sludge solidifies and an inorganic molded body having a predetermined shape can be formed in a short time.

[0029]

EXAMPLES Next, examples of the present invention will be described together with comparative examples.

Examples 1 to 3 First, purified water sludge generated from a water purification plant was calcinated at 500 ° C. for 2 hours and then pulverized to an average particle size of 20 μm. 23.2% by weight of K ₂ O was added to the granular burned sludge thus obtained,
An aqueous potassium silicate solution having a composition of 26.6% by weight of SiO ₂ and 50.2% by weight of H ₂ O, and a filler were prepared at the compounding ratios shown in Table 1.

The granular burned sludge is composed of Al ₂ O ₃ 25
% By weight, 45% by weight of SiO ₂ , balance CaO, Fe ₂
It is composed of O ₃ and MgO.

Then, in each of the examples, the granular calcined sludge, the potassium silicate aqueous solution, and the filler in Example 3 were thoroughly mixed by using a mixing stirrer.

Thereafter, the kneaded product was subjected to an internal measurement of 200 mm × 6.
It was placed in a metal mold of 0 mm × 200 mm and press-molded in Example 1, and poured under vibration in Examples 2 and 3 for molding. After that, it was placed in an oven at a temperature of 85 ° C. and heated for 4 hours. Then, it was taken out from the oven and cooled to room temperature to obtain a sufficiently solidified inorganic molded body.

After that, it was cut into a size of 60 mm × 60 mm × 60 mm, and the compressive strength was measured by the method according to JIS R2206, and the bending strength was measured by cutting into the size of 60 mm × 60 mm × 200 mm and the method according to JIS R2213. The results shown in Table 1 were obtained.

Examples 4 and 5 The calcined sludge, which was calcined under the same conditions as in Example 1 above, was pulverized to an average particle size of 5 μm (Example 4) and 150 μm (Example 5), respectively.

The granular calcined sludge, the same potassium silicate aqueous solution as in Example 1, and the filler in Example 5 were mixed in the proportions shown in Table 1 and thoroughly mixed using a mixing stirrer.

After that, the kneaded product had an internal dimension of 200 mm × 6.
It was molded by pouring it into a metal mold of 0 mm × 200 mm under vibration. After that, put it in an oven at a temperature of 85 ° C for 4
Heated for hours. Then, it was taken out from the oven and cooled to room temperature to obtain a sufficiently solidified inorganic molded body.

Then, the compressive strength and the bending strength were measured by the same method as in the case of Example 1 above, and the results shown in Table 1 were obtained.

Comparative Examples 1 and 2 For comparison, the same operation as in Example 1 was carried out, except that the purified water sludge was dried and crushed without firing, and the purified water sludge obtained was used. There is a point.

That is, the same purified sludge as in Example 1 was dried at 100 ° C. for 5 hours and then pulverized to an average particle size of 20 μm. In this dried and crushed purified water sludge, an aqueous potassium silicate solution having the same composition as in Example 1, and in Comparative Example 2, silica sand having an average particle size of 200 μm was further added as a filler, and they were sufficiently mixed using a mixing stirrer.

Thereafter, the kneaded product was subjected to an internal measurement of 200 mm × 6.
It was molded by pouring into a 0 mm x 200 mm metal mold under vibration. After that, it was placed in an oven at a temperature of 85 ° C. and heated for 4 hours. After that, when taken out from the oven and cooled to room temperature, it was not sufficiently solidified and was in a soft state, and it was impossible to measure the compressive strength and the bending strength.

Comparative Examples 3 and 4 For comparison, the same operation as in Example 1 was carried out, except that the addition amount of the potassium silicate aqueous solution was 30 parts by weight, which was less than the appropriate addition amount of the present invention. (Comparative Example 3), the amount of the potassium silicate aqueous solution added was 200 parts by weight, which is larger than the appropriate addition amount of the present invention (Comparative Example 4).
It is in.

Then, these compositions for inorganic molded bodies were sufficiently mixed by using a mixing stirrer as in the case of Example 1. In Comparative Example 3, since the amount of the aqueous solution of potassium silicate as a liquid component was small, it could not be uniformly mixed with the calcined sludge as a solid component. In Comparative Example 4, the kneaded product was then poured into a metal mold having internal dimensions of 200 mm × 60 mm × 200 mm under vibration to be molded. After that, it was placed in an oven at a temperature of 85 ° C. and heated for 4 hours. After that, when it was taken out of the oven and cooled to room temperature, it was solidified.

With respect to the thus obtained inorganic molded article of Comparative Example 4, the compressive strength and the bending strength were measured by the same method as in Example 1 above. The obtained results are also shown in Table 1.

Comparative Example 5 For comparison, the same operation as in Example 1 above was carried out, except that the particle size of the granular calcined sludge was set to 300 μm, which is outside the range of the appropriate particle size of the present invention. It is in.

Then, the composition for an inorganic molded body was sufficiently mixed by using a mixing stirrer as in the case of Example 1. After that, the kneaded product is 100 mm × 6 in internal dimensions.
It was molded by pouring under vibration into a metal mold of 0 mm x 100 mm. After that, put it in an oven at a temperature of 85 ° C for 4
Heated for hours. After that, when it was taken out of the oven and cooled to room temperature, it was solidified.

With respect to the inorganic molded body thus obtained, the compressive strength and the bending strength were measured by the same method as in Example 1 above. The obtained results are also shown in Table 1.

[0048]

[Table 1]

As is clear from the results shown in Table 1 above, according to the inorganic compositions for inorganic moldings of Examples 1 to 5 of the present invention, the inorganic moldings having higher compressive strength and bending strength than those of Comparative Examples were molded. can do.

[0050]

The composition for an inorganic molded body according to the present invention comprises:
As described above, 100 parts by weight of granular calcined sludge having a particle size of 5 to 150 μm, and an alkali metal silicate aqueous solution 50 to
According to the composition for an inorganic molded body of the present invention, the specific amount of the purified water sludge treated by firing is increased by mixing it with an aqueous solution of an alkali metal silicate and reacting it. An inorganic molded body having mechanical strength can be formed, and the purified water sludge can be effectively used.

Moreover, the moldability is good, the workability of the production is good, the curing reaction can proceed at a relatively low temperature, and the reaction is completed in a short time, so that the productivity of the inorganic molded article is improved. be able to.

Further, since the calcined sludge is used, the material cost is low and the manufacturing cost of the inorganic molded body is extremely low.

Since the obtained inorganic molded article has high mechanical strength, it is extremely useful as a building material and a road material, for example.

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Claims (1)

[Claims] 1. 100 parts by weight of granular calcined sludge having a particle size of 5 to 150 μm and 50 to 50 parts of an aqueous alkali metal silicate solution.
A composition for an inorganic molded body, which comprises 150 parts by weight.