Non-Sintered Quartz Ware and Method for Producing the Same

The present invention relates to a non-sintered quartz ware and its manufacture.

Conventionally, in the manufacture of ceramic and kilned products, such as brick, tile, pottery vessel, except for the steps of comminuting, admixing and shaping, those have to be further subjected to the high temperature treatment, such as firing and sintering. Such treatment causes disadvantage that not only firing requires rather high technic, but also the procedure is relatively difficult to be controlled, which results in high proportion of defective end products. Apart from it, firing causes the product porous and coarse by burning out some amount of combustible ingredients so that the strength of the product is poor. On the other hand, the coarseness render the quality of the fired product poor and the appearance homely. In order to improve its appearance and quality, a coating enamel has to be applied thereto to make it smoother and glossy. However, glazing is unable to obviate the drawback of poor strength. Thus, a non-sintered ceramic ware without need of fire treatment, and possessing excellent strength and gloss is attempted.

It is an object of the present invention to provide a ceramic ware without need to be treated with firing.

It is another object of the present invention to provide a ceramic ware having more dense texture and glossy surface.

It is a further object of the present invention to provide a ceramic ware having excellent mechanical strength and suitable for building materials, for example, brick and tile etc.

It is still another object of the present invention to provide a ceramic ware of which manufacture is simplified.

In accordance with the present invention, a non-sintered ceramic ware is made by the process of: formulating a batch of raw materials consisting of powdered quartz and clay; adding an effective amount of an ore coagulant of which the compsition comprises 2CaO.SiO.sub.2, 3CaO.SiO.sub.2 and 3CaO.Al.sub.2 O.sub.3 ; blending the above components with an effective amount of water, and forming the blended material in a suitable mold; and pressuring and low-temperature heating to dry up the formed mass.

In accordance with one aspect of the present invention, the clay is in an amount of 30 parts to 100 parts by volume of 100 parts of the powdered quartz.

In accordance with another aspect of the present invention, the ore coagulant further comprises 4CaO.Al.sub.2 O.sub.3.Fe.sub.2 O.sub.3 and MgO.

In accordance with further aspect of the present invention, the ore coagulant is in an amount of 20 parts to 50 parts by volume of 100 parts of the clay and the powdered quartz.

The presently preferred exemplary embodiment will be described in detail with respect to the following drawings.

FIG. 1 is a block diagram illustrating the manufacturing procedure of the non-sintered quartz ceramic ware.

Referring now to the flow chart in FIG. 1, the main raw materials adopted in the present invention are powdered quartz, clay and a coagulant composition. The powdered quartz is obtained from the common quartz mineral and the clay can be obtained from kaolinite, montmorillonite or illite. The coagulant can be obtained from an ore coagulant. In addition, pigments and other additives can be added according to the desired quality and colorness.

In the first place, the quartz and clay minerals are separately comminuted and ground. After subjecting to drying to contain less than 4% of water content by volume, they are screened to have the size of more than 40 meshes. Subsequently, the powdered quartz and clay are blended with a coagulant, pigments and other additives until thoroughly mixed. Wherever needed, a proper amount of water is added to make a paste like batch. The batch is molded in different shape by pressing, such as extrusion pressing. The molded product is then dried under the ambient temperature.

The ore coagulant used here is a cementing composition including 2CaO.SiO.sub.2, 3CaO.SiO.sub.2 and 3CaO.Al.sub.2 O.sub.3, together with optionally 4CaO.Al.sub.2 O.sub.3.Fe.sub.2 O.sub.3, MgO and other retardants. In the presence of the retardant CaSO.sub.4.2H.sub.2 O, the coagulant 3CaO.Al.sub.2 O.sub.3 exhibits excellent function of coagulation which effectively bindes the powdered quartz and clay together. In the other aspect the usage of 2CaO.SiO.sub.2 and 3CaO.SiO.sub.2 will highly enhance the mechanical strength of the resulted product. When the above ore coagulant is applied for cementing, suitable amount of water has to be added to make the blended raw material become a paste-like batch for the subsequent steps of pressing and shaping. Concurrently, 3CaO.SiO.sub.2 will hydrolyze to become calcium hydroxide and amorphous 2CaO.SiO.sub.2 (x-1) H.sub.2 O, which incorporating with the clay will sediment to the contacting surface of the molded product with the mold to form a adhesive layer. Therefore, it has to be cautious that the blended materials assuredly overly filled the mold and intimately contacting inner surface of the mold. It can be noted the smoothness and gloss of the molded product will be dictated by the inner surface of the mold.

The powdered quartz is a crystalline polymorph of silica, and has an excellent hardness. When it is blended with the clay and coagulant, the blended batch is naturally formed into a product of excellent mechanical strength. If the shaped product is subjected to firing, the crystal lattice of the quartz will process a polymorphic transformation which will expand the volume so as to deform and crack the product.

It can be noted that the high plasticity of the clay makes the blend easy to be shaped. Yet it will also contribute to the smoothness and fine texture of the end product. Particularly in case kaolinite Al.sub.2 O.sub.3.2SiO.sub.2.2H.sub.2 O is used, its high content of silicon dioxide will manifest the excellent binding force and mechanical strength among clay, kaolinite and ore coagulant.

It can be realized that the proportion of powdered quartz to the clay is varied depending on the desired quality. The proportional ratio of powdered quartz to clay can be ranging from 3:1 to 1:1 by volume. When the volume content of the powdered quartz is higher, the resultant product will be harder, so that more amount of coagulant is needed. The ore coagulant may generally be in an amount of 20 parts to 50 parts by volume of 100 parts of clay and powdered quartz. The proportional ratio of the total amount of powdered quartz and clay to the ore coagulant is preferably from about 4.2-1 to 2.3-1 by volume. When the amount of powdered quartz by volume is equal to that of the clay, the ore coagulant is added in an amount ranging from 25 parts to 4 parts by volume of 100 parts of the total amount of the powdered quartz and clay. Certainly further adding amount of other additives will change the needed amount of ore coagulant.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments but on the contrary, is intended to cover various modifications and equivalent arrangements. For example, waterproof agent, heat insulating agent can be added to achieve the desired properties. Further, iron net and glass fiber can be imbedded therein to reinforce the quartz ware. These are undoubtedly included within the spirit and scope of the appended claims which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures.