550 t/h
of material into the hopper
Quarries & Aggregates
Natural aggregates
France
Carrière de Vignats
Integration of a sludge-treatment line into an existing aggregate-washing water-treatment plant.
33 t/h
of solids to the filter press
Located in the Calvados department and founded in 1920, Carrière de Vignats is a major quarrying site in northern France and is today part of the NGE Group through its Guintoli subsidiary. The quarry is known for extracting quartzite, a rock characterised by high hardness and strength. With annual production of over one million tonnes, the site supplies materials for national infrastructure projects, including ballast for high-speed rail (TGV) and aggregates for high-performance motorway asphalt.
The project challenges
Lagoon-area recovery
The company could no longer expand the capacity of its settling ponds, making it necessary to avoid further land take and reclaim the lagoon area previously used for sludge disposal.
Integration into the existing plant
A new sludge line had to be added to an already operating water-treatment plant, replacing the previous discharge system.
Water saving
The client’s aim was to reduce mains-water consumption by recycling water from the sludge-treatment line, also supporting eligibility for French government incentives related to water conservation.
Tecnoidea’s process-engineering approach
Space-saving design
Despite the size of the filter press (17.5 × 2.5 × 3 m, 60 tonnes) and a 200 m³ sludge tank, Tecnoidea’s engineering team integrated the control room, the sludge tank and the filtrate tank directly into the machine’s support structure, resulting in a compact overall layout of 28 × 7 × 12 m.
High-capacity filter plates
Thicker plates with fewer internal reinforcements (bosses) were used to increase chamber volume and produce larger filter cakes.
Automation
The machine was equipped with an integrated automatic cloth-washing system, featuring a patented multifunction plate shifter and a “core-blow” system that automatically cleans the parts in contact with the liquid sludge. The equipment was integrated into purpose-designed concrete structures.
Land recovery and operational reliability
Land and water recovery
The project reduced both land use (crucial for the quarry’s logistics) and water consumption, reducing the plant’s overall resource demand.
Reliability
The plant runs at a steady rate of 2–3 cycles per hour, handling on average around 25 m³/h of pressed sludge, equivalent to about 45 t/h.
Reduced wear
The filter-plate design reduces wear and extends filter-cloth service life.
Effective cleaning
The automatic cloth-washing system, together with the core-blow, reduces residual sludge build-up and manual maintenance requirements.