JP2000325917A - Production of raw material for ceramic using waste glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a ceramic raw material which can be a substitute for feldspar by using waste glass. SOLUTION: A mixture in which 60-65 wt.% of pulverized waste glass (150 μm or below in maximum particle size, 23 μm or below in average particle size) and 40-35 wt.% of aluminum hydroxide powder are mixed uniformly is molded into a plate by a hydraulic press, and the plate is calcined at 1000-1200 deg.C. The aluminum hydroxide is reacted with the components of the waste glass to produce a feldspar-like components such as nepheline and anorthite. The calcined molding, since sintering is not enough, can be crushed easily to be a ceramic raw material rich in the feldspar-like components. Namely, it can be used as a substitute for feldspar.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an object to effectively utilize industrial waste, and more particularly, to provide a ceramic raw material which can be used as a substitute for feldspar using waste glass. .

[0002]

2. Description of the Related Art Waste glass, such as recovered cullet, which is a crushed product of bottle glass, plate glass, and other glass products, and factory cullet produced in a glass factory, can be recycled and used as glassy raw materials. However, only a part (about 30%) is actually recycled, and the rest is actually treated as industrial waste, and development of new applications is desired.

[0003]

For example, when considering the use of waste glass as a part of raw materials for producing ceramic products such as tiles, sanitary ware, tableware, and the like, particularly as an alternative to feldspar, There is a problem. First of all,
The melting temperature of waste glass is as low as about 700 to 800 ° C. Even if clay is added to it to increase the fire resistance, it rises only to about 1000 ° C, which is a general firing temperature for manufacturing ceramic products. There is a problem that the temperature is significantly different from about 1200 to 1300 ° C. For this reason, when manufacturing a ceramic product using waste glass as a raw material as it is, the conventional manufacturing line cannot cope with the problem. Even if low-temperature sintering is attempted, the product base formed from the clay containing waste glass has a low softening point, and thus easily deforms during sintering. Therefore, products that can be manufactured are limited to products having simple shapes, and products having complicated shapes such as sanitary ware and tableware or large products are difficult to manufacture.

[0004] As a second problem, the components of waste glass are:
Mainly soda-lime glass, alumina Al ₂ O ₃
It is pointed out that the composition is different from that of feldspar in that it hardly contains any components. Although there are special glasses containing an alumina component, such as aluminosilicate glass and aluminate glass, their proportion in waste glass is usually very small.

[0005]

SUMMARY OF THE INVENTION According to the present invention, waste glass is provided.
It is intended to be used as one of the raw materials of ceramic products, especially as a substitute for feldspar. A feature of the method for producing a ceramic raw material used in the present invention for this purpose is to calcine a mixture containing waste glass and an aluminum raw material as main materials to produce a feldspar-like component.

In the above-mentioned manufacturing method, it is desirable that the mixing ratio of the waste glass is 60 to 65% by weight, and the calcination temperature of the mixture is 1000 ° C. or more and 1200 ° C.
It is desirable to set C or less.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a method for producing a feldspar-like ceramic raw material according to the present invention will be described. Waste glass, one of the starting materials, is recovered cullet, which is a crushed or crushed product of bottle glass, flat glass, and other glass products, and factory cullet generated in a glass factory. These can be used as frit. As the aluminum raw material, aluminum hydroxide Al (OH) ₃ is optimal, but other naturally occurring aluminum raw materials such as diaspore, boehmite, and gibbsite can be used or used in combination. When aluminum hydroxide is used as an aluminum raw material, a desirable mixing ratio of the waste glass to the entire main material is 60 to 60%.
Desirably, it is 65% by weight. If the mixing ratio of the waste glass exceeds 65% by weight (the aluminum hydroxide content is less than 35% by weight), the amount of the feldspar-like component decreases because the alumina Al ₂ O ₃ component decreases. Conversely,
When the mixing ratio of the waste glass is less than 60% by weight (when the amount of aluminum hydroxide exceeds 40% by weight), the amount of silica SiO ₂ component, soda Na ₂ O component, and calcia CaO component is reduced. The production amount of the like component is reduced. When a natural material other than aluminum hydroxide is used as the aluminum material, the range of the optimum mixing ratio of the waste glass may slightly vary from the above.

The procedure for producing ceramic raw materials according to the method of the present invention will be described below. The waste glass is finely pulverized in advance and adjusted so that, for example, the maximum particle diameter is 150 μm or less and the average particle diameter (D ₅₀ ) is 23 μm or less.
Next, this waste glass powder 60 to 65% by weight and aluminum hydroxide powder 40 to 35% by weight (total 100% by weight)
Are uniformly mixed, and this mixture is formed into a plate shape using, for example, a hydraulic press. Subsequently, the molded body is calcined. Desirable calcination temperatures are in the range of 1000-1200C. The required length of the calcination time depends on the calcination temperature. For example, at 1000 ° C, 5 hours or more, 1100 ° C
It is more than one hour. By calcining, aluminum hydroxide Al (OH) ₃ reacts with silica SiO ₂ , soda Na ₂ O and calcia CaO components in the waste glass, and nepheline NaAl similar to soda feldspar NaAlSi ₃ O ₈
SiO ₄ and anorthite (anorthite) CaAl ₂ Si ₂
Feldspar-like components such as O ₈ are formed. Calcination temperature is 1000 °
When it is less than C, the amount of the feldspar-like component is reduced, and it becomes difficult to use it as a feldspar substitute. In order to make the proportion of the feldspar-like component 50% or more, it is necessary to calcine at 1000 ° C. or more. However, the calcining temperature is 1000 ° C
However, when the calcination time is short (less than 5 hours), the generation of feldspar-like components becomes insufficient. If calcined at a temperature exceeding 1200 ° C., the feldspar-like component once generated during the calcining may be re-melted. Therefore, the calcination temperature is 120
It is desirable that the temperature be 0 ° C. or less. The molded body calcined in this manner can be easily pulverized because sintering has not progressed much, and becomes a ceramic raw material containing a large amount of feldspar-like components. That is, the ceramic raw materials produced according to the present invention are:
It can be used as a substitute for feldspar, which is a raw material for producing ceramic products.

The embodiments of the present invention are not limited to those described above. For example, in the above example, before calcining, the main material consisting of waste glass and aluminum hydroxide powder was pressure-formed to form a molded body of a predetermined shape, but in some cases,
It may be calcined as it is without molding, as it is. Further, a potassium component may be blended into the main material to generate potassium feldspar or a component similar thereto. In addition, the present invention can be appropriately changed according to the situation of implementation.

[0010]

EXAMPLES [Test 1] 60% by weight of waste glass powder adjusted to a maximum particle diameter of 150 μm and an average particle diameter of 23 μm and 40% by weight of aluminum hydroxide powder (Heidilite H-42 manufactured by Showa Denko) were uniformly mixed. After that, 30 g thereof is weighed and put into a mortar, and ethyl alcohol is added and mixed for 10 minutes. Next, this was dried at 80 ° C., and 5 g of the obtained dry powder was crushed with a hydraulic press at 30 MPa.
Is uniaxially pressed into a disk having a diameter of 30 mm.
This pressed body is calcined at a predetermined temperature of 800 to 1100 ° C. for 1 to 10 hours in an electric furnace. The composition of the obtained fired body is examined by powder X-ray diffraction, and the formation ratio of feldspar-like components (anorthite and nepheline) in the constituent material is measured. The results are shown in FIG.

As can be seen from the graph of FIG. 1, when the calcination temperature is 900 ° C. or less, the generation ratio of the feldspar-like component does not exceed 50%. When the calcination temperature is 1000 ° C., by setting the calcination time to 5 hours or more, the generation ratio of the feldspar-like component can be set to 50% or more. Further, when the calcination temperature is 1100 ° C., 50% or more of the feldspar-like component can be generated by short-time calcination for one hour. From the above test results, it can be seen that if the calcination conditions are appropriately set, waste glass can be used to produce a feldspar-like ceramic raw material.

[Test 2] A ceramic product manufactured using a ceramic material similar to feldspar manufactured according to the present invention (hereinafter referred to as artificial feldspar) and a ceramic product manufactured using natural feldspar were subjected to a shrinkage rate A test was conducted to compare water absorption and bulk density. The test method is as follows. First, the following A and B are prepared as feldspar raw materials, and the following C is prepared as a control.

A (artificial feldspar) / Waste glass and aluminum hydroxide were mixed in the same production method as in Test 1 with a mass fraction of 60:
Artificial feldspars obtained by calcining the mixture mixed at a ratio of 40 at 1000 ° C. for 5 hours, and then pulverizing (the ratio of feldspar-like components is 50% or more) Mackerel feldspar C (control) / comprising only glass, aluminum hydroxide, and clay so as to have almost the same composition as the artificial feldspar of the above A, and unfired. Each composition of the natural feldspar B is as shown in the table of FIG. 2, and the composition of the control example C is almost the same as the artificial feldspar A. In addition, each composition ratio of the artificial feldspar A is obtained by multiplying the composition of the waste glass and aluminum hydroxide used in the production in accordance with the mixing ratio, and based on the value when Ig-loss occurs, This is calculated by correcting

To 66.7% by weight of each of the raw materials A, B and C, 33.3% of Frogme clay was blended.
After uniaxial pressure molding at a pressure of MPa, firing is performed at a predetermined firing temperature in an electric furnace to obtain a ceramic test sample. The shrinkage, water absorption, and bulk density of each specimen were measured, and the relationship with the firing temperature was examined. The test results are shown in the graphs of FIGS.

From these graphs, it can be seen that the ceramic using the artificial feldspar A manufactured according to the present invention has properties similar to those of the ceramic using the natural feldspar B. In both the specimen using artificial feldspar A and the specimen using natural feldspar B, the shrinkage and bulk density increased and the water absorption decreased as the firing temperature was increased. The sample also means that the densification of the substrate is progressing as the firing temperature increases. Moreover, as shown in FIG. 4, since the change graphs of the water absorption rates of the two are very similar, it is presumed that the densification behaviors of both are similar. Therefore, it can be said that the artificial feldspar according to the present invention can be used as a raw material for producing ceramic products as a substitute for natural feldspar. On the other hand, in the specimen manufactured using the unfired control example C, even if the firing temperature was increased, the shrinkage and the bulk density did not change much, and the change in the water absorption was irregular. It is considered that the reason is that the unfired control example C does not contain a feldspar-like component, so that even if this is mixed with clay and fired, it does not become ceramic.

[0016]

According to the present invention, a ceramic raw material that can be used as a substitute for feldspar can be produced by using waste glass and aluminum raw material, so that waste glass that has been conventionally disposed of can be effectively used. It is possible. In addition, the ceramic raw material produced by the present invention can be handled in the same manner as feldspar in producing various ceramic products, so that the existing production line can be used as it is. Despite using waste glass as one of the raw materials,
It can be used as a raw material for producing large products or products having complicated shapes, such as sanitary ware and tableware, which were conventionally considered difficult.

[Brief description of the drawings]

FIG. 1 is a bar graph showing the result of examining the generation ratio of feldspar-like components in a substance obtained by calcining a mixture of waste glass and aluminum hydroxide, concerning Test 1. . Each graph shows that the calcination temperature is 800 ° C.
The values are at 900 ° C., 1000 ° C., and 1100 ° C. In each case, the vertical axis indicates the percentage of the component (%), and the horizontal axis indicates the calcination time (hour).

FIG. 2 relates to Test 2, and is a table showing the compositions of artificial feldspar and natural feldspar used in the production of test specimens.

FIG. 3 relates to Test 2, and is a graph showing a relationship between a firing temperature and a shrinkage ratio of a specimen.

FIG. 4 relates to Test 2, and is a graph showing the relationship between the sintering temperature and the water absorption of a specimen.

FIG. 5 is a graph relating to Test 2 and showing the relationship between the firing temperature and the bulk density of a test sample.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toru Onuki 5-1-1 Koiehonmachi, Tokoname-shi, Aichi Prefecture Inax Corporation (72) Inventor Yukie Murata 5-1-1 Koiehonmachi, Tokoname-shi, Aichi Prefecture Inax Corporation (72) Inventor Takeyuki Yamamoto 5-1-1 Koiehonmachi, Tokoname-shi, Aichi Inside Inax Co., Ltd. (72) Inventor Katsuhiko Akita 12-4 Futaba-cho, Itabashi-ku, Tokyo (72) Inventor Satoshi Kato, Suginami-ku, Tokyo 2-3-6 Eifuku F-term (reference) 4D004 AA18 BA10 CA03 CA04 CA15 CA30 CB15 CC11 DA03 DA06 DA11

Claims (3)

[Claims] 1. A method for producing a ceramic raw material using waste glass, comprising calcining a mixture mainly composed of waste glass and an aluminum raw material to generate a feldspar-like component. 2. The mixing ratio of waste glass is 60 to 65% by weight.
A method for producing a ceramic raw material using the waste glass according to claim 1. 3. The method for producing a ceramic raw material using waste glass according to claim 1, wherein the calcining temperature of the mixture is 1000 ° C. or more and 1200 ° C. or less.