The Use of Silica Brick in the Copper Reverberatory Furnace

Copper reverberatory furnace is traditional equipment for smelting operations fueled by the pulverized coal or heavy oil. 

It is a horizontal rectangle device, consisting of the base, the bottom, the wall, the roof and the metal framework. The main reasons for the damage of the furnace include:

1) Chemical factors: the penetration of melt (slags and impurities in the copper), erosion caused by the diffusion of SO2 in the copper, the oxidation-reduction reaction caused by the changes of the oxygen pressure or low oxygen pressure or some special situations;

2) Thermal factors: the temperature, intermittent thermal shock or the penetration of copper;

3) Mechanical factors: the wear and tear caused by the movement of materials (metals, copper, slags, waste gases, etc.) or some smelting operations such as blowing and reducing, the impact caused by the loading or the stress caused by the improper masonry.

 

Since the copper reverberatory furnace is a flame furnace, the temperature can be as high as 1800℃ and the temperature of the melting tank is about 1350℃. Therefore, the refractories used in it should have good corrosion resistance, good thermal shock resistance and high strength. 

 

The use of silica brick in copper reverberatory furnaces are similar to those in the open-hearth steel furnaces, except that for melts of lead-free metallic copper, silica can be used throughout the furnace except at the slag line. For this work the brick should be as low in porosity as possible to avoid absorption of copper oxide, which slags away the bricks when the furnace is at its maximum temperature. 

 

Silica brick arches in copper furnace work wear much better if they are not insulated. The maximum temperature reached in the copper refining furnaces is approximately 1350℃. Hence, for this purpose some refractoriness might be sacrificed if anything is to be gained thereby in decreased porosity and resistance to spailling.