---
title: "Raw mill / cement mill / coal mill"
description: "Cement plants run three principal mills, each grinding a different material:"
canonical_url: "https://sylio.co/glossary/raw-mill-cement-mill-coal-mill"
last_updated: "2026-06-28T02:29:27.374Z"
---

Cement plants run three principal mills, each grinding a different material:

<table>
<thead>
  <tr>
    <th>
      Mill
    </th>
    
    <th>
      Input
    </th>
    
    <th>
      Output
    </th>
    
    <th>
      Destination
    </th>
  </tr>
</thead>

<tbody>
  <tr>
    <td>
      <strong>
        Raw mill
      </strong>
    </td>
    
    <td>
      Limestone + clay + sand + iron
    </td>
    
    <td>
      Raw meal (cement-fineness powder)
    </td>
    
    <td>
      <a href="/glossary/preheater-tower">
        Preheater tower
      </a>
      
       feed
    </td>
  </tr>
  
  <tr>
    <td>
      <strong>
        Cement mill
      </strong>
    </td>
    
    <td>
      <a href="/glossary/clinker">
        Clinker
      </a>
      
       + gypsum + additives
    </td>
    
    <td>
      Finished cement powder
    </td>
    
    <td>
      Bagging / despatch
    </td>
  </tr>
  
  <tr>
    <td>
      <strong>
        Coal mill
      </strong>
    </td>
    
    <td>
      Raw coal or petcoke
    </td>
    
    <td>
      Pulverised fuel
    </td>
    
    <td>
      <a href="/glossary/rotary-kiln">
        Rotary kiln
      </a>
      
       main burner
    </td>
  </tr>
</tbody>
</table>

## Mill technology

Two technologies dominate:

- **Ball mill** — rotating cylinder containing steel balls; mature, robust, energy-intensive
- **Vertical roller mill (VRM)** — modern preferred design; 30–40% lower energy use; dominant for raw and coal mills

## Mill-related fouling

- **Mill duct fouling** — fine powder coats hot-gas ducts, reducing flow
- **Coarse-fines bridging** in mill discharge silos
- **Sticky cement coating** in cement-mill ducting during high-humidity periods
- **Coal-mill blade and classifier fouling** — fire hazard

[Sonic horns](/glossary/sonic-horn) on mill exhaust ducting and discharge silos prevent the build-up that disrupts mill throughput.

## Related terms

- [Vertical roller mill (VRM)](/glossary/vertical-roller-mill)
- [Clinker](/glossary/clinker)
- [Preheater tower](/glossary/preheater-tower)
- [Sonic horn](/glossary/sonic-horn)