Smeltstroomindex

Smeltstroomindex (SSI) is a metric used in metallurgical smelting to quantify the stability and efficiency of the melt stream during processing. The term combines Dutch words smelt (smelt) and stroom (flow) with index, and is used in industrial contexts to describe an overall indicator of furnace performance.

Calculation in typical implementations involves combining several sub-indices derived from process data, such as temperature stability, metal throughput, slag handling, and energy use. The temperature sub-index measures the rolling-window variance of furnace temperature; the throughput sub-index compares actual metal production to a target; the slag sub-index uses indicators of slag flow and viscosity; the energy sub-index assesses energy use per tonne. The overall SSI is a weighted sum or other aggregation, often normalized to a 0–1 or 0–100 scale. Higher values indicate less stable or efficient operation, while lower values indicate stable and efficient smelting.

Applications include process control, performance benchmarking, and early anomaly detection in both ferrous and non-ferrous smelting operations. It helps operators adjust cooling, feed rates, and slag composition to maintain stable melt conditions and optimize yield.

Limitations involve the need for reliable sensor data and proper calibration to specific furnace types. Different plants may use different weights or sub-indices, which can limit cross-plant comparability. The SSI is most effective when used as a monitoring tool within a broader control strategy rather than a standalone predictor.

History and status: The concept appears in industrial literature as a proposed metric for melt management but is not yet a universally adopted standard.