Leaching Dicalcium Silicates from Iron Ore Sinter to Remove Phosphorus and Other Contaminants

概要

論文の詳細を見る
Although dicalcium silicates can constitute up to 10 vol% of many modern hematite/goethite iron ore sinters, traditional mineralogical investigations of such sinters have largely overlooked this phase and focused on the more abundant iron oxides and ferrites. However, dicalcium silicates have a range of properties that make them unique in sinter parageneses. These properties may contribute significantly to bulk sinter properties and also make dicalcium silicates potentially exploitable in novel upgrading processes. Analyses on a pot grate test sinter have shown that phosphorous (and possibly other elements including potassium and chromium) was heavily concentrated in the dicalcium silicates. A series of etch tests have demonstrated that dicalcium silicates can be selectively removed from the surface of polished sinter samples using weak acids. In addition, bulk leaching trials showed that the phase can also be removed from powdered and coarser (-5 mm) sinter in mild acids. These leaches resulted in a >90 % reduction in phosphorous with a 7 % improvement in iron grade for the powdered material and a 70 % reduction in phosphorous with a 5 % improvement in iron grade for the coarser material. Two novel processes are proposed to exploit the leachability of contaminated dicalcium silicates from sinter: one being a potential route to a high-grade iron product, the other being a return fines washing circuit.
社団法人日本鉄鋼協会の論文
2001-02-15