Due to the poor wettability of molten slag and graphite, graphite to refractory oxides can greatly reduce the infiltration depth of slag refractory material, thereby reducing the thermal spalling and flaking refractories. Therefore, in the iron and steel industry especially some intermittent production equipment such as hot metal pretreatment tank (or bucket), oxygen converter, electric furnace, ladle, extensive use of carbon containing refractories, and achieved good results. Naturally want to carbon containing refractories used in copper, nickel converter, but the effect is not ideal. The former Soviet Union, Japan and China have in copper or Nickel Converter tried MgO – C, C, but the effect is not ideal.
Why the carbon containing refractories in the iron and steel industry especially the effect of oxygen converter steel making is very good, but in the smelting of copper, nickel converter is not ideal?
Metal melt the iron and steel industry is the Fe.c melt. The blast furnace gas contains large amounts of CO, carbon in liquid iron at or near saturation; natural, blast furnace, hot metal pretreatment tank available carbon and carbon containing material. The important task of oxygen converter steel making is to reduce the carbon in liquid iron, steel will precipitate a large number of CO gas, in iron making, converter, oxygen pressure is very low.
Copper or nickel converter blowing to the matte or ice nickel (nickel matte, ice is Cu – Fe – S or Ni – Fe-s sulfide melt) FeS oxidation in the melt of FeO, into the molten slag.
As long as the partial pressure of CO is less than CO equilibrium partial pressure 5.02 × 105 kPa, carbon refractories in carbon will be oxidized. While copper, nickel converter, CO partial pressure is small, far more than the CO equilibrium partial pressure 5.02 × 105 kPa much smaller; thus in refractories containing carbon, oxidation tendency is very large, it is easy to be oxidized. So the copper or Nickel Converter with carbon containing refractory lining, the use effect is not ideal.
没有评论:
发表评论