HDD Slurry Solidification for Safe Handling and Disposal

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Location

São Paulo, Brazil

Application Date

November 2025

Project summary

During a Horizontal Directional Drilling (HDD) project, the generated slurry needed to be dried prior to disposal due to environmental risks associated with water leaching onto public roads and the surrounding environment. The previously adopted approach involved adding 100–200% dry soil to the material, followed by a waiting period of up to one week for complete drying. This method made the process slow, operationally inefficient, and costly.

 

 

The result

With the application of MetaFLO’s solidification reagent, the water present in the slurry was absorbed within up to 30 minutes, eliminating environmental risks and exposure to fines related to leaching. In addition, the solution significantly reduced operational time and the volume of material requiring disposal, resulting in measurable efficiency gains and cost reduction.

• From 6 days to 30 minutes – Drying time required for disposal
• 45% – Estimated cost savings in the process

Context and Challenges

• Critical waste generation:
  Horizontal Directional Drilling (HDD) generates slurry that must be dried to allow proper disposal.
• Operational risk:
  Transporting wet slurry presents significant leaching risks, potentially leading to contamination of public roads, operational accidents, and environmental fines.
• Impact on project schedule:
  The conventional drying process required approximately one week under dry weather conditions, negatively affecting operational efficiency and project timelines.

 

 

 

Implemented Solution

The Environmental Department responsible for the project selected MF003, MetaFLO’s solidification reagent. The dosage was adjusted according to the slurry’s moisture content, varying with material conditions and reaching up to 0.75% for a volume of 6.5 m³ per day. Using the excavator already available on site, the product was incorporated into the slurry and, within up to 30 minutes, absorbed the free moisture, eliminating leaching and enabling safe, efficient, and environmentally compliant handling and disposal of the solidified material.

Technical Details

• Applied product: MF003 – MetaFLO solidification reagent
• Application method: Incorporation of the reagent into the slurry using the excavator available on site
• Treated material characteristics: Slurry with variable moisture content between 40% and 70%, composed of different soil and rock types
• Technical performance: Retention of free moisture and solidification of the material, enabling safe handling and disposal of the waste
• Dosage: Between 0.40% and 0.75% relative to the wet mass of the slurry, adjusted according to moisture content
• Treated volume: Approximately 6.5 m³ of slurry per day
• Reaction time: Up to 30 minutes

Solution Impacts

✓ Operational

• Significant reduction in slurry drying time, from up to 6 days to approximately 30 minutes.
• Elimination of the need to add large volumes of dry soil, with reagent dosages limited to up to 0.75%.

✓ Environmental

• Elimination of leaching risks during disposal, preventing environmental contamination and impacts on public roads.

✓ Financial

• Estimated cost savings of approximately 45% in the overall process.

 

Conclusion

By converting liquid waste into a solid material in approximately 30 minutes, MetaFLO’s solution eliminated one of the main operational bottlenecks of the project. With low reagent dosages and no significant increase in disposal volume, the process became faster, more cost-effective, and more predictable. Beyond operational gains, the solution mitigated environmental risks, avoided legal liabilities, and reinforced the project’s commitment to environmentally responsible practices—resulting in a safer, more efficient, and more sustainable operation.
 

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