What are the Characteristics of refractory bricks required for melting glass?

Refractory bricks must have the following five characteristics to be beneficial to the glass melting process:

(1) The refractoriness of refractory bricks must be higher than the melting temperature of glass:

(2) Do not cause glass defects such as stones, bubbles, nodules, streaks, etc. in the glass melt as much as possible:

(3) It should not dissolve or corrode as much as possible, so that the melting furnace has a long service life. When dissolving, it dissolves uniformly and should not be damaged in advance in a certain part;

(4) Supplement according to quality and quantity at any time;


⑸ The price is reasonable under the premise of meeting the quality requirements.

The goal of the kiln masonry process is to seek refractory bricks and mortars that are close to the above requirements.

Whether it is a crucible furnace, a horizontal flame furnace, a horseshoe flame furnace, a unit furnace, an electric furnace, or a furnace using other heating systems and melting systems, the main component is the feeding part of the batching materials for melting. , melting part, clarifying part and various reclaiming parts. In addition, each melting furnace should also be equipped with a tank or crucible for holding the melt, the upper structure of the kiln, the kiln shaft, etc. The fuel-burning kiln also has a combustion device (small furnace) as well as a flue, an air dam heat device and a chimney. The all-electric melting furnace does not need to install a small furnace and an exhaust device? The tasks to be completed by the refractory bricks in the kiln are various, so the quality and use of the refractory bricks and mortar are also very different.

Alteration process of zirconium corundum bricks in melting pool

The alteration process of zirconium corundum bricks in the melting pool is as follows:


(1) In direct contact with the glass melt, the main way of alteration is dissolution.

(2) The fused zirconium corundum brick begins to have liquid phase exudation at 1300°C, and it is more serious above 1450°C.

(3) After the glass phase seeps out, a cavity is formed, and the glass liquid invades into the brick along the gap by capillary action, and the alkali metal ions and alkaline earth metal ions in the glass rapidly diffuse to the brick body, dissolving Al2O3 and ZrO2 inside the brick body; at this time, the brick The middle mullite phase will first be decomposed by the action of alkali metal ions, and then participate in the glass formation reaction.


(4) With the deepening of the erosion, the alkaline oxides in the molten glass in the furnace react with Al2O3 and SiO2 to form new minerals such as nepheline and feldspar with low melting point, and the CZ eutectic in the brick is eroded to a certain extent, causing some corundum and oblique The zircon disintegrated, and some beaded baddeleyite also began to split and disperse.

(5) Due to the high solubility of Al2O3 in glass, corundum is easily dissolved at the interface between the zirconium corundum brick and the glass melt, while the solubility of ZrO2 in glass is low, and the corundum tends to be completely dissolved and maintain its original appearance. The dissolution of ZrO2 increases the liquid phase viscosity of the melt around ZrO2, which protects the corrosion of ZrO2.

Zhengzhou Shennan Refractory Co.,Ltd are professional in producing glass furnace refractory bricks , any question ,please don't hesitate contact with me.