Use of colemanite for improving the quality of unfritted glazes

Abstract

A thorough investigation of the boron-containing component -colemanite -is performed. Glaze coatings using colemanite are synthesized. The optimal content of colemanite in the batch composition is 3 -6%, which makes it possible to expand the interval of glaze formation by lowering the temperature at which the glassy phase appears from 1150 to 1000°C. While retaining the required physical and chemical properties, the synthesized coatings differ by high values of the aesthetic indicators: brightness -87%, whiteness -89%.Improving the quality of coatings for ceramic sanitary ware while at the same time expanding the raw materials base and lowering the cost of raw materials remains a real problem in modern ceramic production. One indicator which needs to be improved is the quality and aesthetic characteristics of opacified glaze coatings, so that specialists are continually searching for effective compositions and components that can improve these characteristics.The present investigation is devoted to obtaining bright opacified coatings for ceramic sanitary ware fired at high temperature with a natural mineral -colemanite Ca 2 B 6 O 11 × 5H 2 O -added as a boron-containing component; the colemanite is provided by the state company Eti Mine Works G.M. (Turkey). This company was created in 1935 and is the largest Turkish company whose business is to obtain and reprocess minerals. The company produces and supplies a number of enriched boron minerals and purified boron products, such as concentrated colemanite, ulexite, tincal, purified sodium tetraborate pentahydrate Étibor-48, sodium tetraborate decahydrate, water-free sodium tetraborate, and boric acid.Created in 1982 in Finland, the daughter company Ab Etiproducts Oy now has exclusive rights to sell Eti Mine Works G.M. products in Russia and the Commonwealth of Independent States, the Baltic countries, and Scandinavia.Colemanite is an interesting but still little-studied boron-containing mineral which is virtually unused in the ceramic industry. For this reason, a thorough investigation of colemanite and determination of its effect on the physicalchemical properties of glass-crystalline coatings and their phase composition and aesthetic characteristics are of scientific and practical interest. Colemanite can be represented by different morphological formations: crystals ranging from short to long columnar modifications and geodes ranging from granular to continuous aggregates with white, gray, or yellowish colors. Colemanite is characterized by a glassy luster, hardness 4.0 -4.5, density 2420 -4200 kg/m 3 , and perfect cleavage. When heated colemanite dissolves in hydrochloric acid, and it is insoluble in water. Accompanying minerals are gypsum CaSO 4 , kernite Na 2 B 4 O 6 (OH) 2 × 3H 2 O, sodium tetraborate 4[Na 2 B 4 O 5 (OH) 4 × 8(H 2 O)], and ulexite NaCa(H 2 O) 6 [B 3 B 2 O 7 (OH) 4 ]. Colemanite is known as a product of change of pandermite Ca 2 (H 2 O)[B 4 BO 7 (OH) 5 ]. The structure of colemanite (Fig. 1) is represented by infinite chains of [BO 3 ] triang...

An Investigation on Acrylic Organic Coatings Including Colemanite and Zeolite for Glass Materials

“…It is also used in the manufacture of heat resistant glass, and has other industrial, medicinal, and cosmetic uses. It is a popular collector mineral [6][7][8][9][10]. On the other hand, zeolites are aluminosilicate minerals commonly used as microporous, commercial adsorbents and catalysts.…”

Usage of Colemanite in Transparent Wall Tile Glazes

“…They indicated that colemanite additions until to 68% did not create any problems in surface quality of oor tile glaze. Mazure and Levitsky [8] have evaluated the eect of colemanite addition to unfritted glazes in the rate of 36%. Results indicated that the temperature of formation of the liquid phase decreased from 1150 • C to 1000 • C and required physical-chemical properties that maintained for unfritted opacied glaze coating.…”