quote:

---

Charlie, A metallurgist I know just looked at your pictures of slag. He is a steel plant metallurgist and they frequently look at and analyse slag as part a way of measuring the cleanliness of the process. Many things can be told just by the color and his first comment, since there was little black or dark grey, the refining must be quite good since they are reducing the ore very thoroughly. There are relatively few iron residuals. When he saw the yellow colored slag, he thought either that was dirt or they were melting pyrite which is higher in sulfur (we had not at that point seen any indication in the posts they may have been melting pyrite). As for glass-like slags, he thought they were common in cases where the slag is thin and contains high concentrations of silica, as you may have already surmised. The porosity is typical of all slags since various gases are released through the slag during the processing. Beyond that, he felt chemical analysis would give you the additional answers you may need about composition. Seems metallurgists are just highly specialized chemists afterall. Cheers to the team down there. :)

---