JP3017348B2 - Manufacturing method of clay for unglazed tile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing clay for unglazed tiles.

[0002]

2. Description of the Related Art Unglazed tiles used for floor tiles are made of clay, pottery stone, feldspar,
It is manufactured using colored clay produced by mixing a pigment with a raw mineral such as silica stone. Generally, this kind of colored clay is shown in FIG.
As shown in the table, pigment and water are added to the raw material minerals that have been weighed and mixed, and the pigment is mixed while the raw material mineral is crushed by a ball mill to produce a colored slurry.The colored slurry stored in the slurry tank is supplied to a spray dryer by a slurry pump. It is produced by spray drying with hot air. The unglazed tile is manufactured by press-molding and firing the colored clay thus produced.

[0003]

In the above-mentioned conventional production method, a pigment is mixed during the pulverization of the raw material mineral to produce a colored slurry. However, it is a mixture of water, the raw material mineral and a fine solid of the pigment. The colored slurry easily adheres to the inner wall of the ball mill or the ball made of silica or ceramics charged as a grinding medium and remains, and the residual amount sometimes reaches 5 to 8% of the slurry generated in one grinding process. .
In addition, the colored slurry adheres and remains not only in the ball mill but also in a slurry pump, a slurry tank, and a pipe connecting the spray dryer and the slurry tank. For this reason, when the color of the pigment is changed from black to white, for example, the slurry attached to the inside of each of these devices must be washed and removed, and this operation requires a great deal of time, during which the operation of the devices is interrupted. I have to do
The operating rate decreases and the manufacturing cost increases. The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for producing unglazed tile kneaded clay capable of facilitating a cleaning operation at the time of color change, increasing the operation rate of equipment, and reducing costs. And

[0004]

According to the present invention, there is provided a method for producing clay for unglazed tiles, comprising the steps of: wet grinding a raw mineral to produce a colorless slurry containing no pigment; and filtering the colorless slurry by a filter press. A dehydration step of forming a colorless cake by filtration and dehydration, a drying step of drying the colorless cake with hot air, a dry mixing step of dry-mixing the pigment and the dried colorless cake by high-speed fluid mixing to form a colored mixture, a colored mixture Compression molding or extrusion molding to form a colored molded product, dry crushing of the colored molded product to produce colored granules, and dry crushing process of producing colored granules; And a classification step of refining the colored clay.

[0005]

According to the present invention, the pigment is not added to the slurry which is difficult to remove, and the pigment is added only in the mixing step where the treatment method is dry, so that the slurry removal operation at the time of color change can be performed. Easy. Therefore, the operation interruption time of the equipment used for the kneaded clay production is shortened and the operation rate is improved, so that the production cost can be reduced. Further, since the colored mixture is subjected to compression molding or extrusion molding, and then crushed and classified and purified into kneaded clay, the bulk density of the kneaded clay particles increases. Therefore, since the clay does not easily adhere to the molding die during press molding, the cleaning of the die is facilitated. Furthermore, the higher the bulk density, the lower the thermal shrinkage of the tile during firing, so that the dimensional accuracy of the fired tile is improved.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 schematically shows the steps constituting a method for producing a clay for unglazed tile according to a first embodiment of the present invention. . The production method is to add water to the raw material mineral and pulverize it with a ball mill, a wet pulverization step of producing a colorless slurry containing no pigment, the colorless slurry stored in the slurry tank is pressure-fed to a filter press by a slurry pump to be filtered and dewatered, A dehydration step for producing a colorless cake, a drying step for bringing the colorless cake into a tunnel dryer and drying it with hot air, and a dry mixing step for mixing the dried colorless cake and pigment with a high-speed fluid mixer to produce a colored mixture A molding step of compressing or extruding the colored mixture with a roller compressor, a screw type extruder, a plunger type extruder or the like to produce a sheet-shaped, flake-shaped or lump-shaped colored molded product; A dry crushing step in which crushed particles are crushed by a crusher such as a crusher or a cage mill to produce colored granules, and the colored granules are screened. In classified consists classification step of purifying the colored clay required particle size, the colored kneaded material produced by such a series of steps by press molding and baking unglazed tiles are manufactured.

[0007] The high-speed fluidizing mixer used in the dry mixing step is such that a blade attached to the bottom of an upright cylindrical container is rotated at a high speed to disperse and mix the raw materials by strong shearing and impact of the blade. The dried colorless cake is crushed into granules, so that the pigment can be mixed well in a short time. In addition, the cleaning operation can be performed very easily because the structure is simple and small.

According to this embodiment, however, the pigment is not added in the step of wet grinding the raw material mineral by a ball mill.
At the time of color change, a cleaning operation for removing slurry from the inside of each device such as a ball mill, a slurry tank, a slurry pump, and a filter press becomes extremely easy. Accordingly, the operation interruption time of each device is shortened and the operation rate is improved, so that the manufacturing cost can be significantly reduced. In addition, since the colored mixture is compressed and extruded by a roller compressor, a screw extruder, or the like, and then crushed and classified to be refined into clay, the bulk density of the clay particles increases. Therefore, since the clay does not easily adhere to the molding die at the time of press molding, the cleaning operation of the die becomes easy. Furthermore, since the bulk density increases, the thermal shrinkage rate during firing of the tile decreases, so that the dimensional accuracy of the fired tile improves.

[Brief description of the drawings]

FIG. 1 is a process diagram schematically illustrating a method for producing a clay for unglazed tile according to a first embodiment of the present invention.

FIG. 2 is a process chart schematically showing a conventional method for producing a clay for unglazed tile.

Claims (1)

(57) [Claims] 1. A wet grinding process in which raw material minerals are wet-ground to produce a colorless slurry containing no pigment, a dehydration process in which a colorless slurry is filtered and dehydrated by a filter press to produce a colorless cake, and a colorless cake is dried with hot air. A drying step, a dry mixing step in which the pigment and the dried colorless cake are dry-mixed by high-speed fluid mixing to produce a colored mixture, a molding step in which the colored mixture is compression molded or extruded to produce a colored molded article, a colored molding Characterized in that it includes a dry crushing step of dry-crushing the material to produce colored granules, and a classifying step of classifying the colored granules with a screen and purifying them into a colored clay having a required particle size. A method for producing clay for tiles.