How to Distinguish The Quality of Enamel Frit
Many friends in enamel factories don’t know how to distinguish the quality of enamel frit. Hunan Noli Enamel Co., Ltd, as an enamel frit manufacturer, will talk to you about the quality of enamel frit. The quality of enamel frit refers the main chemical composition, content, particle size, moisture content and impurities, especially harmful impurities.
The quality requirements of the main raw materials of enamel frit are as follows:
Quartz (SiO2) is white powder, SiO2≥98%, Fe2O3≤0.1%, ignition loss <0.5%, moisture content <10%, particle size greater than or equal to 20 mesh and less than or equal to 40 mesh.
Silica sand (SiO2) is milky white or light yellow, light pink powder, SiO2 ≥ 85%, Al2O3 ≤ 9%, CaO, MgO, BaO ≤ 2%, Fe2O3 ≤ 1%, ignition loss is less than 1%, and the particle size is greater than Equal to 20 mesh and less than or equal to 40 mesh.
Feldspar (K2O•Al2O3•6SiO2) is grayish white, light yellow, light pink or white powder, SiO2≥68%, Al2O3≤16%, K2O≥12%, alkaline earth metal≤1%, Fe2O3≤0.2%, ignition loss Less than 0.5%, no mica, 100 mesh sieve residue is less than or equal to 5%.
Clay (Al2O3•6SiO2•2H2O), the content of SiO2 is less than or equal to 48%, Al2O3 is greater than or equal to 35%, Fe2O3 is less than or equal to 0.5%, and the content of S is less than or equal to 0.01%.
Boric acid, borax, sodium carbonate, sodium nitrate, potassium nitrate are all required to be free of agglomeration. The purity of magnesium sulfate is more than 98%, the purity of barium chloride is more than 98%, the purity of potassium dichromate (potassium red alum) is more than 97%, and the purity of copper oxide is more than 97%. More than 98% without cuprous oxide and metallic copper pass the 100-mesh sieve completely.
Metal antimony (Sb) where Sb content is greater than or equal to 99%, Fe is less than or equal to 0.1%, sulfate is less than or equal to 0.1%, water insoluble matter is less than or equal to 0.1%, and there is no agglomeration.
Antimony oxide (Sb2O3) has a purity of more than 99%, of which As is less than or equal to 0.25%, and it completely passes through a 100 mesh sieve.
Titanium oxide (TiO2) purity 98.5%, SiO2≤0.3%, Fe2O3≤0.05%, S≤0.05%, water insoluble matter≤0.4%, 325 mesh sieve residue≤0.5%, anatase content greater than 85%.
Cobalt oxide (CoO / Co2O3) contains more than 72% of cobalt and less than 1% of other metal oxides, and completely passes through a 100 mesh sieve.
Nickel oxide (NiO / Ni2O) should have a Ni content of more than 72%, and other metal oxides less than 1%, and it should pass a 100-mesh sieve completely.
There are other raw materials for enamel and glaze. I will not repeat them here. Controlling the quality of raw materials is extremely important for the quality of enamel and glaze. In addition to the quality of raw materials that affects the finished enamel and glaze, the moisture of the raw materials will also affect the batch. The mixing uniformity of the enamel has an impact. Next time, I will talk about the moisture measurement of the enamel glaze raw material.
Quartz (SiO2) is white powder, SiO2≥98%, Fe2O3≤0.1%, ignition loss <0.5%, moisture content <10%, particle size greater than or equal to 20 mesh and less than or equal to 40 mesh.
Silica sand (SiO2) is milky white or light yellow, light pink powder, SiO2 ≥ 85%, Al2O3 ≤ 9%, CaO, MgO, BaO ≤ 2%, Fe2O3 ≤ 1%, ignition loss is less than 1%, and the particle size is greater than Equal to 20 mesh and less than or equal to 40 mesh.
Feldspar (K2O•Al2O3•6SiO2) is grayish white, light yellow, light pink or white powder, SiO2≥68%, Al2O3≤16%, K2O≥12%, alkaline earth metal≤1%, Fe2O3≤0.2%, ignition loss Less than 0.5%, no mica, 100 mesh sieve residue is less than or equal to 5%.
Clay (Al2O3•6SiO2•2H2O), the content of SiO2 is less than or equal to 48%, Al2O3 is greater than or equal to 35%, Fe2O3 is less than or equal to 0.5%, and the content of S is less than or equal to 0.01%.
Boric acid, borax, sodium carbonate, sodium nitrate, potassium nitrate are all required to be free of agglomeration. The purity of magnesium sulfate is more than 98%, the purity of barium chloride is more than 98%, the purity of potassium dichromate (potassium red alum) is more than 97%, and the purity of copper oxide is more than 97%. More than 98% without cuprous oxide and metallic copper pass the 100-mesh sieve completely.
Metal antimony (Sb) where Sb content is greater than or equal to 99%, Fe is less than or equal to 0.1%, sulfate is less than or equal to 0.1%, water insoluble matter is less than or equal to 0.1%, and there is no agglomeration.
Antimony oxide (Sb2O3) has a purity of more than 99%, of which As is less than or equal to 0.25%, and it completely passes through a 100 mesh sieve.
Titanium oxide (TiO2) purity 98.5%, SiO2≤0.3%, Fe2O3≤0.05%, S≤0.05%, water insoluble matter≤0.4%, 325 mesh sieve residue≤0.5%, anatase content greater than 85%.
Cobalt oxide (CoO / Co2O3) contains more than 72% of cobalt and less than 1% of other metal oxides, and completely passes through a 100 mesh sieve.
Nickel oxide (NiO / Ni2O) should have a Ni content of more than 72%, and other metal oxides less than 1%, and it should pass a 100-mesh sieve completely.
There are other raw materials for enamel and glaze. I will not repeat them here. Controlling the quality of raw materials is extremely important for the quality of enamel and glaze. In addition to the quality of raw materials that affects the finished enamel and glaze, the moisture of the raw materials will also affect the batch. The mixing uniformity of the enamel has an impact. Next time, I will talk about the moisture measurement of the enamel glaze raw material.