Guide · Process model

Mass and energy balance for a smelting furnace: the foundation of any furnace model.

Every tonne that goes into a furnace comes out as metal, slag, gas or dust. Every kWh goes into reactions, heating or losses. Closing both balances is how you find where the energy goes.

The mass balance

A mass balance traces every input (ore, reductant, flux, electrode paste) to its outputs (metal, slag, off-gas and dust), element by element. If it does not close, a measurement is wrong or a loss is unrecorded.

InputsOutputs
Ore and concentratesMetal or alloy tapped
Reductants (coke, coal, char)Slag
FluxesOff-gas
Electrode consumptionDust and fines

The energy balance

An energy balance sets electrical input against where the energy goes: the heat needed for the reduction reactions, heating and melting metal and slag to tapping temperature, and losses through off-gas, cooling and the shell.

How to build one for your furnace

  1. Collect per-heat data: charge weights, assays of each input, tap weights, metal and slag analyses, power.
  2. Close the mass balance for the main elements and check the error.
  3. Compute the theoretical energy for reactions and heating from the closed mass balance.
  4. Compare with metered electrical energy; the difference is losses plus measurement error.
  5. Repeat over many heats and calibrate the model so its estimates match the furnace you actually run.

Pitfalls

How Furnace Twin does it

Furnace Twin is a physics model of your furnace (mass and energy balance, slag chemistry, reduction kinetics, an electrical model and furnace zones) calibrated on your heat history and re-calibrated as new heats arrive. It estimates energy, grade and recovery every heat and flags drift with its likely cause, such as basicity, reductant or electrodes. A scenario engine compares reductant, basicity, temperature and feed changes side by side so only the best goes to a short trial on the real furnace. Anyone on shift can ask questions in plain language and get answers that cite records, model runs and literature, and shift handover can be captured by voice in Hindi or English. Every model version is evaluated and logged. Delivery runs baseline, calibrate, then operate, starting with one furnace.

Questions

What is a mass balance for a furnace?

An accounting of every input (ore, reductant, flux, electrode) against every output (metal, slag, gas, dust), element by element, that should close within measurement error.

What is an energy balance for a furnace?

Electrical input set against the energy needed for reactions, heating metal and slag, and losses through gas, cooling and the shell.

Why calibrate a furnace model on plant data?

So its estimates match the specific furnace, ore and practice, instead of a textbook furnace.

See it on your own data. Furnace Twin — Ask the furnace, see the proof. Book a 30-minute working session with an engineer.

General guidance, current as of the date above. Figures and examples are illustrative unless a source is linked.