JPS61219776A - Manufacture of porous ceramic - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a method for manufacturing porous ceramics.

A huge amount of inorganic sludge, such as ceramic sludge and stone sludge, which are industrial wastes, is generated every day, and there is an urgent and strong desire for an effective method for processing and, if possible, an effective method for utilizing it.

On the other hand, various porous materials and adsorbents are used for water treatment such as wastewater, industrial water, and seawater, carriers for microbial treatment, soil improvement materials, water retention materials, deodorizing materials, fragrance materials, and fish cultivation materials. The molded product is being used.

The present invention effectively utilizes the above-mentioned inorganic sludge,
The present invention relates to a method for producing porous ceramics that can be suitably used for such porous materials and molded products thereof.

<Prior art and its problems> Conventionally, no method for producing porous ceramics that effectively utilizes inorganic sludge as described above has been proposed. A method for manufacturing a porous material mainly composed of silica stone and clay and using sawdust as a pore-forming material has been proposed (Japanese Patent Application Laid-Open No. 7549/1983), but this type of conventional method does not meet the above-mentioned problems. In particular, there are problems in that the pores of the porous material produced are large, and there is considerable variation in the size and arrangement of the pores. The manufacturing method itself is also cumbersome.

<Problems to be Solved by the Invention and Means for Solving the Problems> The present invention provides a method for manufacturing porous ceramics that solves conventional problems such as slanting.

Accordingly, the present invention aims to make an inorganic sludge mainly composed of silicon, such as industrial waste ceramic sludge, into an aqueous homogeneous dispersion in the presence of an organic thickening agent, and then add an organic foaming agent and an inorganic coagulant to the inorganic sludge in the presence of an organic thickening agent. In the present invention, O relates to a method for producing a porous ceramic, which is characterized in that a uniform slurry is obtained by adding an agent, and the slurry is appropriately dehydrated and dried as necessary, further molded, and finally fired. The target inorganic sludge has silicon as its main constituent, such as ceramic sludge and stone sludge.
They generally contain trace amounts of various metal compounds, and as mentioned above, these are generated in huge numbers every day, and there is an urgent and strong desire for an effective method for their treatment or utilization.

In the present invention, first, the inorganic sludge is made into an aqueous homogeneous dispersion in the presence of an organic thickening agent. For example, an organic thickening agent is added to a mixture of inorganic sludge and water and the mixture is uniformly stirred. The thickening agent used in this case is PVA (polyvinyl alcohol) or C
O is a water-soluble organic substance such as MC (carboxymethyl cellulose).Next, an organic foaming agent and an inorganic coagulant are added to the above-mentioned aqueous homogeneous dispersion to obtain a homogeneous slurry. For example, by adding an organic foaming agent to an aqueous homogeneous dispersion and stirring vigorously, sufficient foaming can be achieved, and by further adding an inorganic coagulant and stirring uniformly, fine bubbles can be stably contained even inside the dispersion. A uniform slurry is obtained. The organic thickening agent is effective for turning the inorganic sludge into an aqueous homogeneous dispersion liquid, but rather it is effective in turning the inorganic sludge into an aqueous homogeneous dispersion liquid, but it is rather effective in reducing the number of fine particles generated by adding an organic foaming agent to the aqueous homogeneous dispersion liquid and stirring it vigorously. Necessary to maintain stable foam. The organic foaming agent used here may be a foaming agent itself consisting of a combination of compounds, or may be one that can produce sufficient foaming by vigorous stirring, for example, and various commercially available foaming agents may be used. Preferred examples of surfactants include Snowlap H (trade name, manufactured by Nichiryo Kagaku Co., Ltd.) and 5MN-260 (trade name, manufactured by Ippo Co., Ltd.). These foaming agents are hydrophilic organic substances or are mainly composed of hydrophilic organic substances in order to function in an aqueous system and to eliminate them during subsequent baking. Preferred examples of the inorganic coagulant used here include chlorides of magnesium, aluminum, and calcium, and more specifically bittern and alum.

These coagulants are water-soluble inorganic substances that function in an aqueous system to obtain a uniform slurry that does not easily separate, and to make the product skeleton solid after firing.

Finally, the uniform slurry is fired. Prior to firing, it is advantageous to separately dehydrate and dry the homogeneous slurry, and if necessary, shape it appropriately, or mix inorganic pigments in an earlier stage. is also possible.

In this way, porous ceramics are produced, but the types and amounts of the organic thickening agent, organic foaming agent, and inorganic coagulant used, as well as the firing conditions, etc., are particularly dependent on the properties of the inorganic sludge to be treated and the resulting porous sludge. The quality should be selected as appropriate depending on the performance required depending on the use of the ceramic.

<Example> Silica sand sludge discharged from a glass raw material manufacturing factory 10
kg (moisture content: 30 cm, weight; all figures below are based on weight), add 5 kg of water, mix uniformly in a mill, and add PVA (
PVA205, manufactured by Kura V Co., Ltd.) 1.25# aqueous solution!
9 was added and mixed evenly.

1 of Snow Wrap H (listed above) was added to the resulting aqueous homogeneous dispersion.
50 g of an aqueous solution of Nigari was added and stirred vigorously to achieve sufficient foaming, and immediately 150 g of a commercially available Nigari aqueous solution of 1 was added and further mixed uniformly. The homogeneous slurry obtained was dehydrated and dried to reduce its volume to about half, and then heated in an electric furnace to a
It was baked at 00°C for XIO hours.

When the porous ceramic thus produced was crushed,
Countless and uniform continuous fine pores were formed even inside the pores, which was as desired.

<Effects of the Invention> As explained above, the present invention effectively utilizes inorganic sludge, which is generated in huge quantities every day and is difficult to dispose of, and has the advantage of forming countless fine pores uniformly even inside the sludge. This has the effect of making it possible to easily manufacture a robust porous ceramic.

Claims (1)

[Claims] 1. Inorganic sludge whose main constituent is silicon, such as industrial waste ceramic sludge, is made into an aqueous homogeneous dispersion in the presence of an organic thickening agent, and then an organic foaming agent and an inorganic coagulant are added to the homogeneous dispersion. A method for producing a porous ceramic, which comprises obtaining a slurry, dehydrating and drying the slurry as necessary, further shaping the slurry, and finally firing the slurry.