Making Cement Grade RDF

Preparation of blended RDF for cement Kiln

Ajay Badal

5/4/20251 min read

Un-shredded RDF
Blended RDF-Puff
Blended RDF-briquettes

Blended RDF (Refuse-Derived Fuel) Procedure, commonly followed in India to create a fuel mix suitable for use in cement kilns or waste-to-energy plants:

1. Sampling of Raw Material

Sampling is the most important key factor to keep quality control for RDF Mix.

  • Mixture Analysis

  • Moisture Analysis

2. Pre-sorting

  • Manual or mechanical sorting to remove recyclables (metal, glass, high-value plastic).

  • Inerts like stones, sand, and debris are removed.

3. Primary Shredding

  • Bulky items are shredded into manageable sizes (typically 150–300 mm).

  • Reduces volume and enables easier blending.

4. Drying / Moisture Reduction

  • Waste is air-dried or processed through drying tunnels to reduce moisture below 20%.

  • Moisture reduction improves calorific value (CV).

5. Homogenization & Blending

  • Different waste streams (e.g. plastic film, textile, biomass, industrial scrap) are blended to achieve a target calorific value (typically 2,500–4,000 kcal/kg).

  • Blending ensures stable combustion and consistent energy output.

6. Secondary Shredding (Optional)

  • For certain applications (e.g., cement kilns), further shredding is done to 20–30 mm size for uniform feeding.

7. Packaging / Dispatch

  • Blended RDF is stored in silos or baled (wrapped) for delivery.

  • Supplied to cement plants, WtE facilities, or authorized boilers under proper documentation.