Real-Time Slag Analysis: Turning Downtime into Productivity

Waiting is costly — especially in steelmaking. Yet many steel mills still spend up to 15 minutes waiting for slag analysis results before they can take action. In today’s volatile production environment, shaped by recycling and the use of secondary raw materials, that delay directly affects efficiency, quality, and margins.

Why Slag Matters

Slag is more than a by-product. Its composition influences refractory wear, steel cleanliness, and even furnace yield. Without up-to-date data, operators are forced to add safety margins, which means higher additive consumption, more downtime, and unnecessary costs. In short: slow analysis erodes efficiency.

Insert a slag sample into the QLX9 Laser OES slag analyzer

Laser OES plamsa on steelmaking slags

The Limits of Conventional Methods

X-ray fluorescence (XRF) remains a reliable laboratory method, but it requires time-consuming preparation steps such as cooling, grinding, and pressing. The result: long analysis cycles and delayed process corrections — often too late for real-time adjustments.

A Faster Path: Laser-OES (LIBS)

Laser Optical Emission Spectroscopy, also known as LIBS, takes a different approach. A short laser pulse generates a plasma on the sample surface, and the emitted light reveals the slag’s composition.

The advantages are clear:

• Speed: Results in less than a minute instead of 10–15 minutes

• No prep work: Even granular or irregular samples can be measured directly

• Process control: Real-time data enables immediate corrections

By collecting thousands of spectra per second, Laser-OES effectively averages out inhomogeneous samples — turning variability into robust, usable data.

From Data to Impact

Shorter analysis times open new possibilities for process control. Smaller, more frequent adjustments mean:

• Lower additive and flux consumption

• Less refractory wear

• Fewer inclusions and higher quality steel

• Reduced waiting times and downtime

• Faster return on investment through higher throughput

What’s Next?

For Laser-OES to achieve widespread adoption, the industry still needs standardized calibration methods and independent validation studies. Early results, however, show that the technology is competitive — especially for elements like silicon and magnesium.

Conclusion

Laser-OES won’t replace every laboratory method, but it fills an important gap. Whenever time, throughput, and light element analysis matter, it delivers real advantages. Instead of waiting for results, operators can act immediately — and in steelmaking, timing makes all the difference.