Effect of atmosphere and basicity on softening-melting behavior of primary slag formation in cohesive zone

The softening-melting characteristics of ferrous burden play a crucial role in the thickness and position of the cohesive zone. The influence of the basicity and experimental atmosphere on the softening-melting behavior of primary slag under slag-coke interaction was investigated using in situ visualization method. The mechanism was analyzed using the FactSage software, X-ray diffraction, and electron probe microanalysis. The softening and melting temperatures of the samples increased with increasing basicity under different atmospheres. The difference between softening and melting temperatures is smaller in a H-2 atmosphere than in a CO atmosphere; in H-2 atmosphere, the range of softening zone in the cohesive zone was significantly thinner. The formed low-melting-point FeO-bearing phases decrease when H-2 was used as the reducing agent. In addition, according to FactSage calculations, the high content of metallic iron reduced in the H-2 atmosphere raised the softening temperature of the primary slag. It also narrowed and moved downward the cohesive zone due to an increase in softening and melting temperatures. Meanwhile, the increase in basicity promoted the decrease in liquid ratio and improved the permeability of cohesive zone.

Automated summary

This study investigates the influence of basicity and experimental atmosphere on the softening-melting behavior of primary slag. The results show that increasing basicity leads to higher softening and melting temperatures. In a H-2 atmosphere, the difference between softening and melting temperatures is smaller, and the range of softening zone in the cohesive zone is narrower.