Vertical roller mills (VRM) are an attractive alternative to conventional ball mills for improving efficiency and reducing energy consumption in cement plants. However, they can introduce cement quality issues due to cement pre-hydration. Pre-hydration is the reaction of cement with moisture that can reduce compressive strength, set retardation, workability and increase the initial and final set time. These problems cost cement producers roughly $300 million dollars a year*.
TAVERO® VM grinding aids mitigate these issues by requiring less water for stable VRM operation.
Optimizing production without pre-hydration
Pre-hydration forms on the surface of cement grains, acting as a barrier that reduces the reactivity of the cement. This degrades cement strength and increases set times. TAVERO® VM additives optimize cement processing by controlling mill vibration with less water. Using less water lowers pre-hydration - helping to deliver higher quality cement.
Using these cement additives at the optimal dosage allows for decrease in:
- Sprayed water
- Hot gas required to keep the mill at the ideal temperate
- Use of hot gas generator
Historic test results show cement plants are able to increase production up to 37 percent* and decrease energy consumption by up to 17 percent* using TAVERO® VM additives.
For example, a cement plant in Europe was running a VRM and spraying water at 1.5% and milling at 100° C. Using a custom-developed TAVERO® VM cement additive, they achieved 28-day strength gains at +3 MPa through chemical activation and +3 MPa by reducing pre-hydration. In addition, an Asian cement plant also employed a TAVERO® VM cement additive, and was able to reduce initial setting time by 39 minutes, improve three-day compressive strength by +3.3 MPa and enhance 28-day compressive strength by +3.7 MPa.
Using TAVERO® VM additives makes it possible to control mill bed stability while reducing cement pre-hydration.
- Increase cement production
- Decrease energy consumption
- Improve strength with less water
- Accelerate initial setting time
- Deliver higher strength cement
*Reflects GCP internal estimates