Products — Fines & duff
Coal fines and duff supply
Coal duff (0–5 mm) is the most cost-effective solid fuel available to plants that can burn it — fluidised bed boilers, briquetting operations, pulverised systems and blending yards.
We move duff in high volume from washing plants across the Hwange field, with per-tonne pricing well below sized product.
Typical duff specification
Around 5,200 kcal/kg gross as received, ash to 22%, sulphur to 1.1% and moisture to 12%. Screened and washed duff at higher CV is available on request.
Handling and moisture
Duff needs covered storage and a plan for moisture management. We advise on stockpile design, load covering and despatch scheduling to protect the delivered calorific value.
Briquetting feedstock
Several of our customers briquette duff with a binder for retail and institutional heating markets. We supply consistent feedstock and can contract fixed monthly tonnage to secure your production line.
Typical export specifications
| Grade | CV (kcal/kg) | Sulphur | Ash | Moisture | Sizing |
|---|---|---|---|---|---|
| Thermal RB1 | 6,000 | ≤ 1.0% | ≤ 15% | ≤ 8% | 0–50 mm |
| Thermal RB3 | 5,500 | ≤ 1.0% | ≤ 20% | ≤ 10% | 0–50 mm |
| Washed peas / nuts | 6,200 | ≤ 0.9% | ≤ 12% | ≤ 7% | 5–25 mm / 25–50 mm |
| Metallurgical (coking) | 7,200 | ≤ 0.8% | ≤ 10% | ≤ 6% | 0–50 mm |
| Foundry / blast coke | 6,800 | ≤ 0.9% | ≤ 12% | ≤ 5% | 20–80 mm |
| Coal fines / duff | 5,200 | ≤ 1.1% | ≤ 22% | ≤ 12% | 0–5 mm |
Frequently asked questions
- How much cheaper is duff than sized coal?
- Duff typically prices well below washed sized grades per tonne. Request the current price list for dated figures — coal pricing moves weekly.
- Can duff be used in a chain grate boiler?
- Generally not without blending, because fines block airflow. Duff suits fluidised bed and pulverised systems; we will advise honestly on fit.
Related — Products
Need a price for your exact requirement?
Send us grade, monthly tonnage and destination. We reply with a dated price list within one business day.
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