Three equivalent dosage units
| Unit | Conversion | Example |
|---|---|---|
| g/t | grams of product per tonne of treated material | 300 g/t |
| kg/t | g/t ÷ 1,000 | 0.300 kg/t |
| % by mass | g/t ÷ 10,000 | 0.0300% |
Consumption formula
Product kg/h = cement output t/h × dosage g/t ÷ 1,000. For a liquid volumetric pump setting, divide kg/h by the current product density in kg/L. Density must come from the selected grade’s current specification.
Why a generic range is not a prescription
Public industry information often discusses low hundreds of grams per tonne, but the optimum for a particular commercial product must come from its current guidance and controlled trials. Product concentration, cement composition, mill system and objective can all change the working point.
Trial controls
- Calibrate the pump or feeder before collecting results.
- Confirm whether dosage is based on total cement, clinker plus additions or another material stream.
- Maintain equivalent cement quality when comparing throughput.
- Evaluate several documented dosage steps rather than jumping to a claimed optimum.
- Watch for setting, strength, flow or process changes that may indicate an unsuitable dose.
Standards & method references
- ASTM C465 — Processing additions for hydraulic cement manufacture
- ISO 679:2009 — Cement strength test method
- ISO cement, gypsum, lime and mortar standards catalogue
The applicable standard, edition and local regulatory requirement must be confirmed for each project. A reference does not claim product compliance.
Worked example: mass, volume and stock
Illustrative inputs only: 100 t/h of cement, a user-selected 300 g/t dose, 20 h/day and 25 days/month. These are not recommended operating values or a product specification.
| Quantity | Calculation | Result |
|---|---|---|
| Product mass per hour | 100 × 300 ÷ 1,000 | 30 kg/h |
| Daily consumption | 30 × 20 | 600 kg/day |
| Monthly consumption | 600 × 25 | 15,000 kg/month |
| Volume with an assumed density of 1.20 kg/L | 30 ÷ 1.20 | 25 L/h |
The density is invented for this example, not an IN-5 value. Replace it with the current grade-specific value at the relevant conditions. Mass-based consumption alone is not a pump calibration or evidence of effective performance.
Common basis mistakes to resolve before comparing quotes
- Product mass versus active-solids mass: name the basis and the current solids fraction; do not substitute one for the other.
- Cement output versus clinker feed: use the material basis specified for the selected grade.
- kg/h versus L/h: volumetric conversion needs density; grams per tonne is not grams per hour.
- Planned capacity versus observed throughput: label estimates and actual records separately.
Use the mass-consumption calculator, then retain the assumptions in the trial review record. For a named-grade discussion, use IN-5 consumption planning.