Flint quartz powder

Flint quartz powder

The natural resources of quartz are not enough to meet the demand of industry, so the quartz must be converted by high temperature (over 1500°C) in rotary furnace with the help of catalyst to synthesize quartz.

It appears as pure white powder, insoluble in water, and is produced by calcining high-quality natural quartz at approximately 1500°C, followed by pollution-free grinding, magnetic separation, and classification, resulting in a stable product. The silicon content exceeds 99.5%, with a crystal structure of the tetragonal system, hardness of about 6.5, and density of 2.45.

The high purity quartz powder obtained after high temperature calcination can be stabilized by rapid cooling. It is widely used because of its stable chemical properties, reasonable and orderly controlled particle size distribution, large specific surface area, high porosity, good weather resistance, good anti-sedimentation and good thermal shock resistance.

It serves as a refractory material in enamel glaze, enhancing the firing range of enamel paste to prevent over-firing of enamel products. When added to the base enamel, it ensures the integrity of the base enamel layer even after multiple firing cycles. Quartz also improves breathability, preventing glaze cracking and fish-scale cracking.

2. Product Particle Size Correspondence Table:

3. Conventional physical properties of cubic quartz powder:

4、main features ：

1、high hardness;

2、high purity, over 99%;

3. Small thermal expansion coefficient;

4. The whiteness reaches over 95%;

5. Unique refractive index;

6. Excellent insulation properties;

7. Chemically stable, it does not react with any other substances except with hydrofluoric acid and strong alkalis.

V. The Specific Role of Our Company's Quartz Powder in Ceramic Glaze

1. In the glaze, it can interact with the fusible materials CaO, Na2O, K2O, MgO, and melt to produce transparent quartz glass, enhancing the glossiness of the glaze surface, making it transparent and bright.

2. The low thermal expansion coefficient and good heat resistance of the square quartz powder prevent the defects such as bending deformation during the sintering of glaze.

3. The softening temperature is high, and the viscosity of the liquid phase is large at high temperature, which can improve the plasticity of the glaze.

4. It can enhance the mechanical strength, improve the hardness of the glaze surface, make the porcelain products wear-resistant, and also has good chemical stability, not affected by acid erosion.

5、This process imparts a transparent and glossy finish to the glaze surface. In ceramic tile production, quartz typically constitutes 10-20% of the body material. For single-fired glazed tiles, the quartz content is reduced to 10-15%, while in glaze frits, it ranges from 20-40%. White bodies require higher quartz purity, whereas colored bodies can utilize lower-purity quartz. In the production of single-fired wall and floor tiles, quartz is usually not added directly to the body; instead, silica (SiO2) is incorporated through clay additives.

VI. The Role of Square Quartz Powder in Porcelain Body:

1. Quartz powder is a basic raw material that significantly influences ceramic green bodies both at room temperature and during heating. Prior to firing, quartz powder in the green body regulates the plasticity of the clay, reduces shrinkage during drying, shortens drying time, and prevents deformation (including warping and collapse) of the green body.

2. During the heating process of fused feldspar powder, a phase transformation occurs with volume expansion, which can partially offset the shrinkage of the green body. Since the phase transformation of quartz induces volume changes, the cooling and heating rates must be meticulously controlled during both heating and cooling processes to prevent cracking of the product.

3. During firing, the thermal expansion of cubic quartz powder effectively counteracts the shrinkage of the ceramic body. Moreover, as the glassy phase becomes abundant, it forms the structural framework of the ceramic, preventing defects such as bending deformation during firing.

4. The chemical affinity of the powder is very strong, and it can combine with many kinds of oxides. The viscosity of the liquid phase is very high, which increases the bonding ability of the body.

5. The square quartz powder can also increase the mechanical strength and transparency of the body.

VII. Scope of Application:

1. Mainly applicable to: enamel glaze

2. Suitable for casting coatings, chemical products, polishing materials, interior and exterior wall coatings for construction, automotive primers, and adhesives.

3、Suitable for epoxy castables, potting compounds and precision casting, rubber and plastic fillers, abrasives, cables and so on.

VIII. Performance and Applications

1. Excellent optical properties. The refractive index of 1.47 is closer to that of PE, PP, and certain resins. When mixed, it does not mask the original color of the pigment; however, using other fillers may result in a lighter or distorted appearance of the pigment.

2. Matting effect: Used in high-end paints to reduce the mirror-like reflection on the paint film surface, creating a rough texture to achieve a matte finish.

3. Features high scattering efficiency, excellent light extinction, high whiteness, low density, and glossy color. Its specific structure facilitates light reflection, making it a viable alternative to glass microbeads in reflective coatings. This material not only enhances slip resistance but also improves the paint's reflectivity. With a whiteness range of 92-95%, it can partially replace titanium dioxide in coatings and paints, reducing formulation costs. It is suitable for use as a primer in automotive applications and as a filler in various coatings and paints.

4. Corrosion-resistant, scratch-resistant, scrub-resistant, and heat-resistant.

5. Free from organic pollutants, with extremely low metal content and minimal conductivity. It enhances the UV resistance of coatings and exhibits excellent insulation properties, making it suitable for packaging and filling of electronic products.

6. Excellent thermal shock resistance: When heated to approximately 220-240°C, the material undergoes thermal expansion to compensate for the shrinkage of epoxy resin, gypsum, and other materials during curing at these temperatures, ensuring minimal deformation during casting. This property makes it particularly suitable for applications such as nylon casting, epoxy casting compounds, potting compounds, and precision casting. In nylon and all resin systems, adding modified quartz powder can reduce the shrinkage ratio of the resin during cooling.

7. Applications in adhesives:

With low oil absorption and smooth texture, this material exhibits lower viscosity than silica (which is alkaline) and superior weather resistance. It demonstrates excellent adhesion (with a roughened surface resembling quartz), high peel strength, and high surface resistance. The modified material achieves better compatibility with epoxy resin systems, effectively eliminating bubbles and sedimentation. During formulation, adding diatomaceous earth in appropriate proportions can further enhance bonding performance.

Silica fume exhibits numerous cleavage planes with distinct angular features, making it difficult to bond. Kaolin, in its hexagonal flake form, turns red upon firing and also demonstrates multiple cleavages (making it difficult to bond).

8. Square quartz powder is commonly used as a anti-caking agent in transparent PP, PE, LDPE, and LLPDE film production. Given its matching refractive index, this additive has negligible impact on the optical properties of most polyolefin films. Other specialized applications include ultra-thin films and double-extruded films, which require ultra-fine-grade quartz powder. 600-mesh quartz powder is typically employed as an IR-absorbing material in greenhouse films.

9. The square quartz powder has the characteristics of high surface energy, hydrophilic and oleophobic surface, and easy agglomeration, so it is difficult to disperse uniformly in non-polar or weakly polar paint. Therefore, the surface modification of the square quartz fine powder is necessary, so that the surface of the quartz particles is covered with a layer of organic matter (such as coupling agent, surfactant, etc.), so that it becomes hydrophobic and oleophilic. This not only enhances the compatibility and bonding force between the square quartz powder and the matrix, but also improves the dispersion of the quartz.