Corrosion resistance of refractories made from low-cement concretes for glass making

Abstract

The corrosion resistance of samples made of low-cement concrete to a bottle glass melt was investigated in dynamic conditions at a temperature of 1350°C; they are used for production of articles used in glass-forming machines.The domestic refractory industry does not fully satisfy the needs of the glass industry with respect to the assortment and quality of most of the refractories manufactured for glass-melting furnaces [1 -3]. For this reason, glass works use furnaces in conditions of lower (sometimes by 1.5 -2 times) output of glass melt from the melting area or to increase output, purchase foreign high-quality refractories which are several times more expensive than the domestic analogs, which affects the cost of the products manufactured.The quality of the refractories in direct contact with the working media in the glass-melting furnace (roof, walls, bottom of the melting part, etc.) plays an important role in ensuring high-quality glass products. In addition to the refractories in the melting zone, the articles in the production part (feeder elements and glass-forming machines), which have a complex configuration with elevated requirements both with respect to performance characteristics and with respect to shape and size as a function of the application, have a large effect on quality. During their lifetime, refractories are exposed to the intensive effect of the glass melt and important thermal and mechanical stresses, so that they must have high glass and thermal stability, strength, and must also provide for constant assigned parameters of feed of the glass melt for processing and its temperature homogeneity [4].The production channel or feeder channel directly adjacent to the working part of the tank is designed for feeding glass melt to the feeder and then processing it by the glass-forming machine. The temperature of the glass melt in the feeder channel is 1000 -1350°C as a function of the type of glass. The concrete temperature is established to ensure a uniform decrease in it to the level determined by the viscosity of the glass melt required for forming. Defects in the form of stone, ripples, and seeds that enter with the glass melt and appear in reaction of the glass melt with the refractory lining cannot be assimilated directly in the channel by the glass mass. For this reason, the refractories for lining the feeder channel must satisfy certain requirements; the basic requirement is slow, uniform dissolution in the glass melt without formation of any defects.Many requirements are imposed on refractories used in glass-melting furnaces; the most important one is corrosion resistance to the glass melt (glass resistance) [5 -7]. The glass resistance, characterized by the rate of dissolution of a refractory in a glass melt, is a function of many factors: the chemical and mineral compositions and the structural features of the refractory, the chemical composition and viscosity of the glass melt, the surface tension on the boundary of the glass and the refractory, etc.In the domestic scientific and te...

Production of refractory concretes and practice in using them in glass-melting aggregates

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Mathematical modeling of quartz particle melting process in plasma-chemical reactor

“…This is because the super high viscosity of silica melt even at temperatures exceeding 2000°С and its higher volatility [1][2][3]. The low-temperature plasma (LTP) used for silicate melting possesses a high energy concentration and 3000-5000°С temperature that will allow achieving the required viscosity of silicate melt and providing its uniform heating [4][5].…”

A study of the corrosion resistance of refractory concretes to a melt of borosilicate glass under dynamic conditions

“…It has been noted previously [5] that a contact layer characterized by substantially higher viscosity by comparison with the viscosity of the glass melt is formed in the interaction of refractory materials with a glass melt. A dynamic method of testing for corrosion resistance is therefore used.…”

“…Tests were performed on samples measuring 20´20´250 mm in a melt of borosilicate glass from the firm of OAO Tver'steklo and ZAO Borosovsk Glass. The samples were tested at 1350°C with the use of a special high-temperature plant according to the technique described in [5].Diagrams that display the degree of corrosion of the samples and the depth to which the glass melt penetrated samples of refractory concrete of differing compositions are presented in Fig. 1, while Fig.…”

“…Tests were performed on samples measuring 20´20´250 mm in a melt of borosilicate glass from the firm of OAO Tver'steklo and ZAO Borosovsk Glass. The samples were tested at 1350°C with the use of a special high-temperature plant according to the technique described in [5].…”