JP2006045042A - Method of manufacturing granular glass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of easily and inexpensively manufacturing a zeolite substance to be easily used in consideration that zeolite used for the purification of soil, water treatment or an ammonium treatment of fish farm water is hard to be handled and does not come into wide use by the economical reason though the usefulness is well known. <P>SOLUTION: The porous fine granular body having the surface formed into zeolite is manufactured by allowing a silica raw material heated to a high temperature to react with an aluminum salt aqueous solution directly in the atmosphere. As the silica raw material, waste soda-lime glass, steel making slag or granulated slag is used and heated to the high temperature and an aqueous solution of deficient components as zeolite is added thereinto. The mixture is sprayed to be rapidly cooled and allowed to react with each other to make the raw material small-sized to increase the surface area and the surface is partially formed into zeolite. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention mainly relates to a method for producing a granular material obtained by zeolitizing the surface, which is effectively used for seabed covering sand, water treatment, soil improvement materials, etc., for the effective use of waste glass and steel slag.

In recent years, foamed glass processed from waste glass bottles or the like as raw materials has been used for soil purification, seabed sand cover, water treatment, or fish farm water ammonium treatment, and the foam glass has a large surface area and a certain amount of cations. Utilization of an adsorption action is performed. This foam glass is obtained by heat treatment with a foaming agent using waste glass such as a waste glass bottle as a main raw material, and since there is no problem of metal elution, it is extremely lightweight and its specific gravity can be controlled to some extent by manufacturing conditions. In addition, because it has good water retention, it is used for slope greening, soil backfilling, beach treatment, and the like. Sandy glass with a glass particle size of several millimeters or less is a pulverized product such as a waste glass bottle, which is not as large as foam glass, but has a large surface area and active glass fracture surface, and has the same ion adsorption capacity as foam glass. Therefore, it is used for seawater treatment and fish farm water treatment that require a relatively large specific gravity. Such sandy glass and foamed glass can be more selectively adsorbed while maintaining their characteristics as the use expands, or water retention is improved, for example, soil purification, better retention of fertilizer, etc. Requests are getting higher. In fish farms and the like, there is an increasing demand for more advanced treatment such as treatment of eutrophication such as ammonium ions contained in water. In order to cope with these problems, natural zeolite is added to such foamed glass or sandy glass, or a relatively inexpensive artificial zeolite is added for use in processing. However, glass alone is insufficient, and the zeolite and glass body are completely different in shape, so it is inconvenient to handle in a lump, inevitably tends to be biased, and zeolite with extremely small particles flows in water. In order to make it uniform, it took time and effort to granulate the zeolite. Further, since zeolite is generally expensive, there is a tendency that economical efficiency becomes a problem when it is used in a large amount.

Zeolite is conventionally produced by a hydrothermal method in which alkaline components such as aluminum, silicon, and sodium are made liquid. In addition, it has been shown that as a so-called artificial zeolite production method, zeolitic solid materials are produced, but they are from coal ash and incinerated ash, both from aluminosilicate, and the aluminum component and silicate component are combined in advance. It is obtained by reacting an alkali component that is easy to react with it. These are all made into a zeolite in a bulk state. Therefore, they are in the form of fine powder in the result, and as described above, the handling workability is not necessarily good, and it is not always handled as it is for treatment of seawater and fish farms or for soil burial. It was not easy.

In other words, typical examples of the past are shown in the following patent documents, all of which are obtained from synthesis of a solution of aluminum, silicon and alkali, or to obtain a bulk zeolite by reaction of aluminosilicate and alkali. It was.
Soda glass typified by bottle glass or soda lime glass originally has very few aluminum components, and it is necessary to introduce aluminum, which is a constituent element of zeolite, but it is difficult to bond aluminum compounds and silicon compounds. Because of this, the technology for producing zeolite by binding in a short time was not known at all.
Japanese Patent Application Laid-Open Nos. 2001-213619 and 2001-240409 describe so-called synthetic zeolite production methods. That is, a technique has been shown in which aluminate is used as an aluminum raw material in a liquid aqueous solution, and water glass, which can also be handled as a liquid, is added as a silicon component, and heated or pressurized in an alkaline solution to obtain zeolite. In this method, all the constituent components are mixed as a liquid and crystals are generated from the liquid.

On the other hand, Japanese Patent Laid-Open No. 10-324518 is a method for producing a so-called artificial zeolite, which uses an aluminosilicate such as incinerated ash or coal ash as a raw material, and acts on alkali, and is heated at 100 to 120 ° C. and air pressure of 1 to 2 kg / cm 2 G. A process is described in which a zeolite is produced by treatment using a continuous circulating fluidized bed under conditions. This changes aluminosilicate into zeolite.
JP-A-6-321525 and JP-A-6-321526 show a method and an apparatus for zeolitization by applying an alkali to a coal ash made of aluminosilicate to form a slurry and treating it at a hydrothermal condition of 90 to 100 ° C. Has been.
In Japanese Patent Application No. 11-225320 (Patent No. 3090657), it is said that incineration ash or aluminosilicate is used as a raw material, and a zeolite is continuously produced by applying an electromagnetic wave of 300 MHz to 30 GHz as a heat source. Has been done.
All of these show a process for producing bulk zeolites, but the zeolites produced by these are all fine powders and have excellent properties such as cation exchange capacity, but the production process is complicated. In use, there is a problem that granulation is required or extra work such as coating on the surface of another medium is required, and handling is not always easy. There was also a problem that it was inevitably expensive.
JP 2001-213619 A JP 2001-240409 A JP-A-10-324518 JP-A-6-321525 JP-A-6-321526 Japanese Patent Application No. 11-225320 (Japanese Patent No. 3090657)

The problem to be solved is that zeolite used for soil purification, water treatment, or ammonium treatment of fish farm water is not easy to handle, and it is expensive, so even if its usefulness is known economically In reality, it was not possible to spread the materials, but taking these into consideration, it was an object to establish a manufacturing method for producing a zeolite material in an easy-to-use form and at a low cost.

The present invention relates to a method for producing a porous fine particle having a zeolitic surface by contacting a silica raw material heated to a high temperature with an aqueous solution of an aluminum-containing salt directly in the atmosphere, and comprising the silica raw material As waste treatment soda lime glass, steel slag and granulated slag are cheap, sometimes using products available as a reverse charged material, heated to a high temperature state, there is insufficient as a zeolite component In order to achieve this object, the surface area of the granular material is increased by zeoliticization by refining by heat shrinkage, and by subjecting the component to be contacted by spraying in the form of an aqueous solution and quenching, to rapidly increase the surface area. became.

Waste soda-lime glass, which is a raw material, is architectural waste glass, glass waste bottles, bulb glass, and the like, and is also important in terms of glass recycle. In addition, steel slag, which is a raw material, will inevitably come out with the production of steel, mainly composed of silica components, with components similar to soda lime glass except for soda such as calcia and alumina, Its melting point is high enough not to contain soda. Currently, some of it is used as a roadbed repairing agent and cement additive, but its high added value is desired. Granulated slag is one of steel slag, which has been made microporous by rapid cooling with moisture, and is used for marine sand cover, but its use is not sufficient. These are used as raw materials to be finely granulated, and the insufficient component as zeolite is added in the form of an aqueous solution to make the surface zeolitic so that it can be used for various applications. In addition, it is said that the cation exchange capacity, which is one of the characteristics when zeoliticized, plays a major role in the Si / Al ratio contained therein. Here, the main component of the raw material is silica, so aluminum is added. At the same time, by adding alkali, the raw material surface can be melted and reacted with aluminum and alkali to achieve hydrothermal conditions at substantially high temperature and low pressure together with the water vapor component, thereby achieving surface zeolitization. it can. Note that the zeolitization here is not aimed at the bulk body, but is aimed at zeolitization on the surface of the granular body, which is a suitable purpose.

By spraying such an aqueous solution from the surface, bulk glass and slag are finely granulated while zeolitizing from the surface due to the difference in thermal expansion (shrinkage) between the surface and the inner surface. Becomes zeolitic. When glass is used as a raw material, it is heated to 573 ° C. or higher, which is the so-called α-β transition temperature of quartz, and rapidly cooled in that temperature range, thereby not only thermal expansion and contraction but also substantial transition. Since miniaturization occurs at the same time, the surface can be effectively broken to obtain a glass having a larger surface.

When granulated slag is used as a raw material, since it is substantially glass, it exhibits almost the same characteristics as glass. However, it may be left as it is because it is partially fine and originally has a large surface area, but the heating temperature is set to 1000 ° C. or higher in order to produce surface-zeolitic granulated slag aimed at further miniaturization and large surface area. It is desirable. The surface of the heated granulated slag is also refined by spraying or showering it with aluminum hydroxide such as sodium aluminate, sodium hydroxide, or an aqueous solution in which aluminum or aluminum hydroxide is dissolved in a sodium hydroxide solution. Promote zeoliticization. In this case, since the surface crystals may interfere with the entire surface, it may be difficult to zeolitize the entire surface. In such a case, silica alumina and alkali components such as a mixed solution of sodium silicate and sodium aluminate may be used. Zeolite can also be formed by spraying a combined aqueous solution onto heated granulated slag. The spraying may be done in any way, but it is necessary to react with a sufficient amount of steam with a certain degree of quenching. For this purpose, it is better to be closer to the shower than spraying a fine aqueous solution that blocks air.

The steel slag, which is the precursor of granulated slag, is taken out as a melt, and the surface is refined directly by spraying an aqueous solution containing alkali and aluminum instead of water under the same conditions as granulated slag production. At the same time, a hydrothermal condition is formed in the cooling process to form zeolite.

According to the present invention, by a relatively simple operation, a fine granular surface can be obtained from raw materials such as waste soda lime glass such as a waste bottle from which raw materials can be obtained easily, inexpensive granulated slag, or molten steel slag at the time of steelmaking. A zeolitic porous granular product can be obtained. Unlike bulk zeolite, this zeolite does not require re-granulation and other operations and can be used as it is, and the manufacturing cost is very low. In addition to some conventional applications such as water treatment, It is expected to have a very wide range of applications, such as soil improvement, seaside improvement for shore cover sand, and eutrophication prevention treatment. Furthermore, it can be widely applied to planting applications such as sand replacement and soil replacement, which have been conventionally performed, including the meaning as a fertilizer retaining material, and can exhibit the intended effect.

The production conditions differ slightly depending on the silica raw material. For soda lime glass, soda in aluminum and glass is melted by spraying or spraying an aluminum-containing salt solution at about 800 ° C., which is melted from about 600 ° C. In addition, by reacting the silicon component, it is possible to obtain a fine granular material that is fine and porous and has zeolite formed on the surface thereof. Also, when granulated slag is used, it is already microporous, so it is not always necessary to melt it. If it can be about 800 to 1000 ° C, it is heated to 1000 ° C or higher, and the alkali and aluminum components are added to it. For example, sodium aluminate aqueous solution containing excess caustic soda, which may be obtained by dissolving aluminum or aluminum hydroxide in caustic soda, is directly sprayed at a concentration of about 5 to 20% as sodium aluminate. As a result, it is considered that the alkali dissolves the surface, adds aluminum and silicon content, and is further zeoliticized and further refined in a water vapor atmosphere, so that a granulated body whose surface is zeoliticized is generated. On the other hand, for steel slag, it is not very good to melt the cooled slag itself, and in the process of producing granulated slag from molten slag, an aqueous solution containing alkali and aluminum is sprayed instead of water. By creating a water vapor atmosphere and reacting silicon, aluminum, and alkali components on the surface, and making it finer while cooling and solidifying, it is easy to form granules with the same shape as granulated slag and the surface is zeoliteized It will be obtained. All of the granular materials obtained by these have a bulk specific gravity of about 1 to 1.5 g / ml, and the cation exchange capacity is 30 to 100 meq / 100 g, depending on the component silicon / aluminum ratio.

A waste glass bottle pulverized product heated to 800 ° C. and melted was placed in a crucible, and a 5% aqueous solution of sodium aluminate was pressurized from above and sprayed as a shower. The glass was cooled and solidified in a state filled with steam and water vapor in the enclosure, and further solidified and cooled for about 15 minutes. When this product was taken out, a white granular material having an apparent particle size of about 0.5 to 2 mm was obtained. The cation exchange capacity (CEC value) of this product was measured and found to be 65 meq / 100 g. Further, when the surface crystal was identified by the X-ray diffraction method, it was not remarkably traced, but a diffraction line corresponding to A-type zeolite was observed.

A commercially available granulated granulated slag was tapped to form a granule, which was put in a crucible and heated to 1100 ° C. When the temperature is sufficiently uniform, the surroundings are covered with a shield in the same manner as in Example 1, and an aluminum or alkaline aqueous solution is prepared by dissolving an aluminum foil in a 10% aqueous caustic soda solution to ½ equivalent of caustic soda. This was used as a shower from the top and reacted. The inside of the container became water vapor, and the temperature dropped to 60 ° C. in about 30 minutes. This was washed with water and dried. Granules with a white surface were produced. It was 50-55 meq / 100g when the cation exchange capacity (CEC value) was measured about this thing. In addition, the CEC value of the granulated slag which did not perform this process was 10 meq / 100g or less.

An aqueous solution obtained by dissolving sodium aluminate and sodium silicate in a molar ratio of 1: 1 so that the soda content was 1 mol / l was used as a treatment solution. For simulation of steel slag, CaO: 45. SiO2: 40, Al2O3: Powder mixed to 15 mol%, 2% caustic potash is added as a flux, kneaded, heated to 1600 ° C, melted, and then the temperature is lowered by 100 ° C as a raw material The aqueous solution was sprayed from the molten slag surface at a high temperature while applying a pressure of 10 cm-aq. This was continued for about 30 minutes, and the entire temperature reached about 60 ° C., so the contents were taken out and further cooled with tap water. In this way, the appearance of a granular material similar to that of granulated slag was obtained, and particles having a white surface could be obtained. When this sample was subjected to X-ray diffraction measurement, it showed a pattern similar to A-type zeolite. Further, when the cation exchange capacity was measured, it was found to be 45 to 50 meq / 100 g, which was almost the same as the granulated slag whose surface was zeoliticized.

The granulated material that has been zeoliticized in this way as a soil improver has good retention of moisture and fertilizer, and works effectively to prevent soil acidification due to partially remaining alkali. At the same time, it works effectively for plant growth. Moreover, since the bulk specific gravity is larger than 1 g / ml, it can be used effectively for seabed sand. In addition, this makes it possible to remove eutrophication components from seawater, and as a result of the retention of bacteria, continuous seawater treatment can be carried out, so that water quality can be maintained more effectively. . Furthermore, when it is put in a live fish cage, it can be expected to work effectively for treating both water and soil because the mortality of live fish is reduced because the decomposition of ammonium ions is promoted.

Claims (8)

A method for producing a porous and fine granular material whose surface is zeoliticized by allowing a silica raw material heated to a high temperature and an aqueous solution containing an aluminum salt to directly contact and react in the air. 2. The method for producing a granular material according to claim 1, wherein the silica raw material heated to a high temperature is soda-lime glass and is heated to a glass softening point or higher. The silica raw material is steel slag, the aluminum-containing salt aqueous solution is an alkali component and an aluminum salt-containing aqueous solution, and the molten steel slag is sprayed with the aluminum-containing salt aqueous solution and cooled while reacting. A method for producing a particulate material. The silica raw material is granulated slag, the aluminum-containing salt aqueous solution is an alkali component and an aluminum salt-containing aqueous solution, and the aluminum-containing salt aqueous solution is sprayed on the granulated slag heated to a semi-molten state and cooled while reacting. The method for producing a granular material according to claim 1. 5. The method for producing a granular material having a zeolitic surface as claimed in claim 1, wherein the spraying is a shower and the reaction is carried out in an atmosphere filled with water vapor in the container. 7. The method for producing a granular material according to claim 1, wherein the aluminum-containing salt aqueous solution is a sodium aluminate aqueous solution. 7. The method for producing a granular material according to claim 1, wherein the aqueous salt solution containing aluminum is an aqueous solution in which aluminum and / or aluminum hydroxide is dissolved in an aqueous caustic soda solution. 6. The method for producing a granular material according to claim 1, wherein the aqueous aluminum salt solution is an aqueous solution containing aluminum, silicon and caustic soda.