Enamel Frit Manufacture

Oxides, carbonates, fluorides and nitrates of the following elements are usually utilized  

Fluorine can be incorporated as fluorspar, cryolite or alkali hexatluorosilicate. 

Raw materials for enamel frit manufacture Oxides, carbonates, nitrates and fluorides of  

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Another large appHcation is as an ingredient in the production of charcoal briquettes. The amount of sodium nitrate used in charcoal briquette manufacture depends on the type and amount of wood and coal used. Typically charcoal briquettes contain up to almost 3% sodium nitrate. Sodium nitrate is also used in the manufacture of enamels and porcelain as an oxidizing and fluxing agent. In porcelain—enamel frits used for metal coating, the amount of sodium nitrate in a batch varies with the various metal bases to be coated, typically from about 3.8 to 7.8 wt %. 

Anhydrous borax is used in the manufacture of glasses, glass wool, and metallurgical fluxes. Other uses are in enamels, frits, and glazes. It also is applied in fertilizers. 

Sheet steel preparation Manufacture of enamel frit... 

The manufacture of enamel frits and the actual enameling are dealt with in greater detail in Sections 5.4.4 and 5.4.5 respectively. 

Use Fluoridation, laundry sours, opalescent glass, vitreous enamel frits, metallurgy (aluminum and beryllium), insecticides and rodenticides, chemical intermediate, glue, leather and wood preservative, moth repellent, manufacture of pure silicon. 

The preparation of the enamel slip includes ball milling the frit and raw materials to the appropriate consistency. Frit is the glassy raw material that makes up the backbone of porcelain enameling. Most frit is manufactured outside the operation but some plants do include captive operations. Other raw materials, such as clay and gums, are mixed into the frit by the ball mill that then releases this mixture to the coating operation.3 6... 

Most enamels melt at ca. 1250°C. Only a few difficult to melt frits require temperatures of ca. 1350°C. The raw materials are smelted, but not, as in glass manufacture, refined. Fig. 5.4-1. schematically. shows the construction of drum and flame-heated tank furnaces. 

Stains and oxides (ceramic colorants) with an average particle size up to ca. 10 pm and a broad particle size distribution, are in some cases manufactured at still higher temperature, up to 1400°C. The higher primary particle sizes are necessary because a more or less strong solubilization of the particles takes place during the firing of the enamel or ceramic frits. The component to be enameled or glazed is coated with a mixture of intensively mixed frits and colorants then fired at temperatures between 500 and 1200°C. 

Recent developments in porcelain include powdered frit and the use of cold rolled steel Instead of enameling iron. Porcelain steel requires a high fusion temperature, 1500 F. This has led appliance manufacturers to seek alternatives to porcelain. 

In the ceramic industry, zinc oxide is used in the manufacture of glasses, glazes, frits, porcelain enamels and magnetic ferrites. Here, the largest consuming plants are in the tile industry. 

Calcium fluoride (Fp. 1423 °C solubility in water 0,02 g/1 at 20 °C) is employed in aluminium metallurgy, brake lining, glass manufacturing, enamel [63] and glazing frits production, dental applications and in the production of welding agents. 

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