Refractory Materials Used In Copper Converters

The service life of copper converters is up to many factors such as the lining materials, smelting method and operation. 

In order to select the right refractory materials, first we must understand the mechanism of destruction of refractory lining. 

 

The lining refractory bricks of copper converters are subjected to the action of damage during use. The stress can act on the lining through chemical, thermal and mechanical factors.

 

The chemical factors include:

(1) The corrosion caused by melt infiltration mainly comes from slags and matte

(2) Corrosion caused by the diffusion caused SO2 in matte

(3) The oxidization or reduction caused by low oxygen partial pressure or oxygen pressure changes

(4) special circumstances, such as hydration when using raw ore or starting heating in rebuilt converters 

 

The physical factors include:

(1) the temperature determined by the heating and the exothermic reaction during smelting

(2) intermittent thermal shock caused loading or abnormal operation

(3) copper infiltration

(4) thermal fatigue caused by recurring periodic temperature changes

 

The mechanical factors include:

(1) the wear caused by the moving of materials (such as metal, matte, slag, charge, exhaust gases full of dust, etc.) and smelting, blowing and reducing during the smelting process

(2) loading or impact stress caused by stab outlet

(3) mechanical fatigue caused by cyclical loading changes

(4) stress caused by improper construction of refractory bricks

 

All the factors above can cause corrosion on the lining of refractory bricks. The interaction of the stress can cause damage on the bricks. The refractory bricks used in the lining, especially the tuyere and slag line, should have good slag resistance, high density, good thermal shock resistance and high strength. 

 

The lining of the copper converter is commonly built with magnesia chrome brick or chrome magnesia brick. Since magnesia bricks have poor resistance to non-ferrous metal slag and thermal shock, they are seldom used. 

 

The tuyere and slag line are the weak points of the converter lining. Since the temperature fluctuates and slag corrosion is severe in these parts, high quality direct bonded magnesia chrome brick or fused magnesia chrome brick are used here.