Refractory Testing to Capture Real-World Applications.
By C. E. Semler
He stated that selection and execution of appropriate tests remains at the crux of the development of successful refractory solutions, and reviewed some recent attempts to develop tests connected to real-world applications as follows:
- Tests for impact-resistant products for aluminium contact applications. Tests for aluminium contact use have focused on non-wetting characteristics, varying furnace temperature, duration, atmosphere control, and molten Al chemistry. But mechanical properties of non-wetting refractories also need to be considered, because there are high impact areas in the furnaces. Vesuvius developed an automated sledgehammer test that led to a family of products which would not fail despite hundreds of impacts.
- Taphole clay drillability. A practical, widely accepted method for measuring or calculating the drillability of anhydrous taphole clays (ATHC) remains to be developed. Quantitative data are needed to assess a rage of different ATHC compositions. Prior methods have been proposed, but none have been adopted as industry standards. Review of drillability has led to the field of geology where a study of the drilling of rocks and sediments has results in various ratings schemes and indexes. Seemingly this experience will be useful to develop a method evaluating/comparing the drillability of ATHC.
- Raw materials testing. Evaluation of incoming raw materials, and maintaining consistent quality, are very important factors for refractory producers. Cluster analysis is a statistical method of differentiating and grouping samples; using X-ray diffraction (XRD) analysis based on a set of previously determined variables and datasets, raw materials can be tested as received to determine if there are any anomalies that need prompt attention by Quality Assurance. Vesuvius has begun applying this technique to incoming bauxite, including the monitoring of different particle size ranges.