KR960011330B1 - Process for the preparation of building materials of slag - Google Patents

Abstract

The process comprises adding more than one or two elements selected from the alkali group consisting of NaOH, KOH and NH4OH to said slurry; and then molding them. The alkali solution is spreaded or the molded body is submerged in it, and then dehydrated. The blended raw material comprises 40-70 wt.% slag, 3.0-33.0 wt.% gypsum, 1.0-5.0 wt.% slaked lime, below 20 wt.% perite and below 15 wt.% reinforcing fiber.

Description

Manufacturing method of slag building materials

1 is a graph showing the change in bending strength according to pH when the pH change of the slurry is adjusted with NaOH during the initial forming.

2 is a graph showing the change in bending strength according to pH when the pH change of the slurry is adjusted to KOH during the initial molding.

3 is a graph showing a change in bending strength according to pH when the pH change of the slurry is adjusted to NH ₄ OH during the initial forming.

4 is a graph showing the change in bending strength according to pH when the pH change of the slurry is controlled by mixed alkali during the initial forming.

5 is a graph showing the change in bending strength according to pH when spraying aqueous alkali solution on the super-molded product.

6 is a graph showing the change in bending strength with curing time during pH adjustment.

The present invention relates to a method for producing a slag building material used as a building material such as lightweight plates and blocks as an inorganic material mainly composed of slag, and more particularly, a slag that can accelerate curing reaction and shorten curing time. It relates to a manufacturing method of building materials.

Slag generated from blast furnaces is usually limited to cement additives, crushed aggregates, etc., depending on their characteristics, but recently, the use of slag has been expanded to various fields such as building materials and ceramic materials.

Blast furnace slag is divided into lumped slag and crushed slag, lumped slag is a slag obtained by slow cooling of molten slag in air, and hydrated slag is made by quenching molten slag with water. It is a material containing a large surface energy to achieve a stable structure, etc., and the ions flowing out of the slag glass is moved through the solution to form a new hydrate to maintain the shape bonded to each other.

On the other hand, in order to manufacture the slag building material, the non-hardened building material mainly made of slag is molded by using hydrated slag, gypsum, and alkali stimulant made by quenching with water having an amorphous rate of 90% or more, and cured curing material is manufactured through a curing reaction.

In order to maintain formation and strength after curing, the blending state and hardening method of raw materials are very important, and the time required for curing the slag building material is directly related to productivity. Done.

Conventional methods related to this are (a) a method for curing slag-based inorganic materials, characterized in that magnesium hydroxide is used as part of the alkali agent in slag curing reaction in the presence of alkali (Japanese Patent Publication No. 58-84167) (b) Blast furnace slag powder A method of manufacturing by using an anhydrous method based on a hydrated slag, characterized in that the crude body is prepared from a slurry containing gypsum and fibrous powder, and an aqueous ammonium salt solution is used in the manufacturing process (Japanese Patent Office 56-120564). , And (c) lactic treatment of blast furnace slag, the addition of hydrated lime or quicklime to the lactic acid blast furnace slag slurry to prepare a slurry pH of 12 or more and kneading lime addition slurry to form and harden the blast furnace slag building material, characterized in that The method (Japanese-special office 58-88157, and Japanese special-purpose office 61-17461) etc. are mentioned.

MEANS TO SOLVE THE PROBLEM The present inventor conducted research and experiment in connection with promotion of hardening reaction at the time of manufacturing slag dry material, and based on the result, this invention proposes the present invention. It is an object of the present invention to provide a method for producing a slag building material, which is capable of mass curing in a short time by promoting a curing reaction by appropriately adjusting the pH of a molded product.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention is a method for producing a slag building material by kneading a blended raw material blended in a conventional compounding ratio, and then molding, curing and drying, alkali group for pH adjustment consisting of NaOH, KOH and NH ₄ OH in the slurry It relates to a method for producing a slag building material, characterized in that the addition of one or two or more selected from to adjust the pH of the slurry to 12.5 ~ 13.5, and then molding.

Hereinafter, the present invention will be described in more detail.

According to the present invention, the blended raw material for producing the slag building material may include crushed slug, gypsum, and slaked lime as main raw materials, and calcium carbonate (CaCO), pearlite, and reinforcing fibers, etc. may be added as secondary raw materials.

The hydrolyzed slag has a specific ratio of 90% or more, and the particle size is 3500 to 5000 cm 3 / g (Blain surface area), the distribution is preferably close to the median, and the basicity [(Al ₂ O ₃ + CaO ) / SiO ₂ ] is preferably contained in about 1.4 ~ 1.9, Fe ₂ O ₃ is within 5wt%, and even when the content of TiO ₂ is large, it is preferable to control because it adversely affects the hydration reaction. And, the preferable content of the chain slag is about 40 ~ 70wt%.

Gypsum has (CaSO ₄ · 2H ₂ O) gypsum and hemihydrate gypsum, which can be used in the present invention, and P ₂ O ₅ in the gypsum acts as a reaction retardant to delay the chemical reaction, and therefore 3wt% or less It is preferable to maintain the phosphate gypsum, especially in the case of phosphate byproducts, since P ₂ O ₅ reacts with Ca ions in the slurry to form a precipitate (CaHPO ₂ · H ₂ O), which affects and granulates. It is necessary to adjust the particle size, the preferred particle size is to maintain 1200 ~ 2800 cm 3 / g (Blaine Surface Area).

When the amount of the gypsum added is about 3.0 to 33.0 wt%, the slaked lime is used as a stimulation accelerator in the hydration reaction with calcium hydroxide, and it is preferable to use a powder having an average of 5 μm or less at 4,000 to 7,000 cm 3 / g.

The preferable addition amount of the said slaked lime is about 1.0-5.0 wt%. The calcium carbonate (CaCO ₃ ) is a hydrated reaction of shrinkage expansion during the manufacture of the board as a weight agent, and this reaction is added to mitigate such impact because it acts as a major cause of cracking of dry materials, the particle size is 2,500 About 12-15 micrometers is preferable at -3,000 cm <3> / g. The addition amount of the calcium carbonate is preferably 20wt% or less.

The pearlite is added as a lightweight agent to reduce the density of the dry materials, the particle size of which is preferably in the foam state of the range of 80 ~ 130g in the volume of 500ml occupies 80wt% or less than the standard 60 mesh. .

The amount of the pilite added is preferably 20 wt% or less. Examples of the reinforcing fibers include pulp, asbestos, and the like, and pulp may be used for recycling pulp or pure pulp, including general newspapers and advertisement papers.

The preferred amount of the reinforcing fibers is 15 wt% or less.

The above-described blended raw materials are mixed at an appropriate blending ratio to prepare a slurry by a conventional method, and then molded. In this case, the concentration of the slurry is preferably limited to 4-5%.

In the present invention, the pH of the slurry should be adjusted to 12.5 to 13.5 by adding one or two or more selected from the alkali group for pH adjustment consisting of NaOH, KOH and NH ₄ OH to the slurry.

The reason for limiting the pH of the slurry to 12.5 to 13.5 is that when the pH of the slurry is 12.5 or less, the activation energy is low and the surface of the particle has a small amount of dissolved ions, so that the curing reaction rate is slow. This is because safety problems and corrosion of equipment are largely problematic, the rate of increase in bending strength is small, and cracks may occur on the surface of building materials.

As the molding method applicable to the present invention, any of the press molding, the mold molding and the super forming molding can be used.

In the case of the present invention, the pH may be adjusted by adding the above-described alkali for adjusting the pH before molding, but the pH may also be adjusted by immersing the molded article in the alkaline solution for pH adjustment or spraying the alkaline solution for pH adjustment on the molded body. have.

The slag building material is manufactured by undergoing curing and drying processes of the molded article molded as described above.

At this time, the curing process is a method of steam curing to maintain the temperature up to 60 ℃ for 24 hours, and then naturally cooled method, the drying process is dried for about 40 minutes in a drying furnace of about 170 ℃ after drying the water content is 8 The method to make it% or less is preferable.

The present invention will be described in more detail with reference to Examples.

Example 1

Slag: 65% by weight, Gypsum: 13% by weight, slaked lime: 2% by weight, calcium carbonate: 5% by weight, pearlite: 5% by weight and reinforcing pulp: 10% by weight of raw materials, kneaded After the slurry was made of%, NaOH was added to the slurry, and the pH of the slurry was adjusted to 12.5 to 13.5 as shown in Table 1 below, followed by curing and drying to prepare a slag building material.

At this time, the curing is to maintain a natural cooling after 24 hours after heating up to 60 ℃.

The bending strength value of the slag building material manufactured as described above was obtained, and the results are shown in FIG. 1 together with those of the conventional material without adjusting the pH.

As shown in Figure 1, it can be seen that the case of adjusting the pH of the slurry at the time of annealing to 12.5 ~ 13.5 with NaOH is superior in the bending strength compared to the case of not adjusting the pH.

In other words, if the pH is not adjusted, the bending strength is 164kgf / cm3, whereas when the pH is 12.5, 172kgf / cm3 and the pH is increased, the bending strength is continuously increased, but the increase rate is not very large at pH 13.5. Is showing.

Example 2

A slag building material was prepared in the same manner as in Example 1, except that KOH was used as the pH control, and the bending strength was measured. The results are shown in FIG. 2 together with the case where the pH was not adjusted. .

As shown in FIG. 2, it can be seen that the same trend as in Example 1 is shown.

Example 3

A slag building material was prepared in the same manner as in Example 1, except that NHOH was used as the pH control, and the bending strength was measured. The results are shown in FIG. 3 together with the case where the pH was not adjusted. It was.

As shown in FIG. 3, it can be seen that the same trend as in Example 1 is shown.

In sum of the above Examples 1 to 3, it can be seen that the hardening reaction is promoted in accordance with the pH, almost irrelevant to the type of alkali for pH adjustment.

Example 4

As the alkali for pH adjustment, the slag building material was manufactured by the same method as Example 1 except that the aqueous alkali solution which combined NaOH, KOH, and NHOH in the ratio of 1: 1: 1 was used.

The flexural strength values of the manufactured slag building materials as described above were measured, and the results are shown in FIG. 4.

As shown in FIG. 4, it can be seen that Example 4 exhibits the same tendency as Examples 1 to 3, which suggests that pH is controlled rather than alkali type.

Example 5

Slag dry material was prepared in the same manner as in Example 1, except that the pH of the slurry was sprayed onto the pH-adjusted superstructure without controlling the pH of the slurry without adjusting the pH of the slurry. Then, the bending strength value was measured, and the results are shown in FIG.

As shown in FIG. 5, the curvature of the slag building material prepared by spraying the aqueous solution of pH 12.5 was 169 kgf / cm 3, which was applied to the curvature value of the building material prepared with the pH of the slurry at 12.5 172 kgf / cm 3. It is slightly lower than that, but it can be seen that it has almost the same effect.

Therefore, in the present invention, curing the curing and drying by spraying the aqueous alkali solution to the uncontrolled superstructure or the molded body without controlling the pH of the slurry at the time of the initial annealing can be promoted.

Example 6

Slag dry material was prepared in the same manner as in Example 1 except that the slurry pH was adjusted to 12.5 and the curing time was changed to 14, 16, 18, 20 and 22 hours, and then the strength of the slag was adjusted. It measured and the result is shown in FIG.

As shown in FIG. 6, the curvature value of the dry materials cured for 18 hours or more is 168 kgf / cm 3 or more, which is superior to the curvature strength of the dry materials cured for 24 hours with the pH-adjusted superstructure. have.

Therefore, there is an advantage that the curing time can be shortened by increasing the strength of the stimulus by using an alkali for pH adjustment, thereby shortening the curing time, and low temperature curing is also possible.

As described above, the present invention uses the slag and gypsum and other inorganic materials to manufacture the unreacted slag building material through the annealing process and to produce a hard slag building material through the curing and drying process to build a ceiling material for walls, walls, other partition materials Since it is possible to use, etc., it is effective to contribute to the expansion and utilization of slag which is a by-product generated in the steelmaking process.

Claims (5)

In the method for producing a slag building material by kneading a blended raw material blended in a conventional blending ratio, and then molded, cured and dried, the slurry from NaOH, KOH and NH ₄ OH in the pH adjusting alkali group The method of producing a slag building material, characterized in that the addition of one or two or more selected to adjust the pH of the slurry to 12.5 ~ 13.5, and then molding. The aqueous alkali solution of which the pH is adjusted to 12.5 to 13.5 by adding one or two or more selected from an alkali group for pH adjustment consisting of NaOH, KOH and NHOH, or spraying the molded article on the molded article. A method for producing a slag building material, characterized in that it is immersed in an aqueous alkali solution and then cured. The method for producing a slag building material according to claim 1, wherein the concentration of the slurry is 4 to 5%. According to any one of claims 1 to 3, wherein the blending material is wt% hydroslag slag: 40-70%, gypsum: 3.0-33.0%, slaked lime: 1.0-5.0%, CaCO ₃ : 20% or less, Perlite: 20% or less, and reinforcing fibers: 15% or less of manufacturing method of the slag building material, characterized in that the composition. The method for producing a slag building material according to claim 4, wherein the molding is performed by a super molded body.