Blast Furnace Calculator

Blast Furnace Charge & Yield Calculator

Production Estimates

Estimated Pig Iron: kg

Estimated Slag Volume: kg

Coke Rate: kg/tPI

Est. CO2 Emissions: kg

Note: Estimates based on standard stoichiometry and reduction efficiency (approx. 94% Fe in Pig Iron).

function calculateBlastMetrics() { var ore = parseFloat(document.getElementById('ironOreWeight').value); var fePct = parseFloat(document.getElementById('ironPercentage').value) / 100; var flux = parseFloat(document.getElementById('fluxWeight').value); var coke = parseFloat(document.getElementById('cokeWeight').value); var cPct = parseFloat(document.getElementById('carbonPercentage').value) / 100; if (isNaN(ore) || isNaN(fePct) || isNaN(flux) || isNaN(coke) || isNaN(cPct)) { alert("Please enter valid numbers for all charge parameters."); return; } // Pig iron production: Assume iron is 94% of the final pig iron weight var totalFe = ore * fePct; var pigIron = totalFe / 0.94; // Slag estimation: Gangue (Ore – totalFe) + Flux var gangue = ore – totalFe; var slag = gangue + flux; // Coke Rate: kg of coke per ton of pig iron var cokeRate = (coke / pigIron) * 1000; // CO2: Simplification of C + O2 -> CO2. 12g C produces 44g CO2 (3.67 ratio) var co2 = (coke * cPct) * 3.667; document.getElementById('pigIronOutput').innerText = pigIron.toFixed(2); document.getElementById('slagOutput').innerText = slag.toFixed(2); document.getElementById('cokeRateOutput').innerText = cokeRate.toFixed(2); document.getElementById('co2Output').innerText = co2.toFixed(2); document.getElementById('resultsArea').style.display = 'block'; }

Understanding Blast Furnace Stoichiometry

A blast furnace is a complex chemical reactor designed to reduce iron oxides into liquid metallic iron. This calculator helps metallurgists and students estimate the performance of a furnace based on the "burden" (the raw materials fed into the top).

Key Input Components

• Iron Ore: Primarily hematite (Fe₂O₃) or magnetite (Fe₃O₄). The percentage of iron (Fe) dictates the yield.
• Coke: Serves dual roles as a fuel for heat and a reducing agent (CO gas) to strip oxygen from the ore.
• Flux (Limestone): Calcium carbonate (CaCO₃) reacts with the impurities (silica and alumina) in the ore to form liquid slag.
• Hot Blast: Pre-heated air injected at the bottom to ignite the coke and facilitate the high-temperature reduction process.

Calculation Logic: Pig Iron vs. Slag

The "Pig Iron" output represents the hot metal produced. While molten, it typically contains about 93-95% iron, 3-4.5% carbon, and small amounts of silicon and manganese. Our calculator uses a standard 94% iron purity factor.

Slag is the essential byproduct that floats on top of the molten iron. It is formed from the non-metallic components of the ore (gangue) and the added flux. Correct slag volume and chemistry are vital for removing sulfur from the iron.

The Importance of the Coke Rate

The Coke Rate (expressed as kg of coke per metric ton of pig iron) is the primary metric for efficiency. A lower coke rate indicates a more efficient operation, often achieved through higher blast temperatures, oxygen enrichment, or pulverized coal injection (PCI).

Example Calculation

If you feed a furnace with 2000 kg of Iron Ore (at 60% Fe content), 800 kg of Coke, and 300 kg of Flux:

1. Pure Iron Content: 2000 * 0.60 = 1200 kg Fe.
2. Pig Iron Yield: 1200 / 0.94 ≈ 1276.6 kg.
3. Slag: (2000 – 1200) + 300 = 1100 kg.
4. Coke Rate: (800 / 1276.6) * 1000 ≈ 626 kg/tPI.

This data allows furnace operators to balance the chemistry of the charge to ensure high-quality hot metal while minimizing fuel costs and environmental impact.