Efficient Wastewater Treatment and Recycling Process Flow - Stone Processing Case
Introduction
Stone wastewater / construction wastewater - including saw cutting, grinding, and shaping - generate significant volumes of rinsing and cooling wastewater. This effluent primarily contains stone powder (composed of SiO₂, CaO, and CaCO₃), along with minor quantities of diamond particles, abrasive fines, and washed silt. Effective treatment enables Water Recycling, reducing both environmental impact and operational costs.
A typical treatment process consists of:
● Wastewater: Equalization → Coagulation → Flocculation → Lamella Clarifier → Reuse
● Sludge: Homogenization Mixing → Automatic Filter Press → Off-site Disposal
1. Chemical Reaction
Stone wastewater is characterized by high specific gravity and rapid settling of Suspended Solids. A tubular reaction system is therefore recommended.
In this design, a pipeline mixer is added to the inlet pipe. Chemicals are dosed at the injection port of the mixer, allowing thorough mixing and reaction with the wastewater as it flows through the pipe. This tubular reaction approach offers a small footprint and low cost.
2. High-Efficiency Solid Liquid Separation - Lamella Clarifier
The Lamella clarifier achieves rapid solid-liquid separation through four stages: energy dissipation and filtration, balanced water distribution, solids-liquid separation, and clarified effluent discharge.
● Energy dissipation & filtration: A specially designed filtration device at the top removes large particles and reduces inflow disturbance, maintaining stable laminar flow inside the unit.
● Balanced water distribution: A distribution chamber ensures uniform, dead-spot-free flow distribution.
● Separation: PVC lamella packs (German engineering) divide the flow into multiple independent separation zones, preventing cross-flow turbulence and ensuring stable, clean effluent.
● Effluent collection: Clarified water is collected via a triangular weir and trough system before discharge.
● Sludge discharge: A multi-sided bottom hopper design enhances sludge removal and prevents bottom compaction and hardening. Optionally, a sludge-thickening scraper can be installed to optimize sludge discharge conditions.
Advantages over conventional concrete sedimentation basins:
| Feature | Lamella Clarifier | Traditional Basin |
| Footprint | ~1/10 of traditional | 1× |
| Settling efficiency | 3–5× higher | 1× |
| Installation | Integrated, simple, fast | Complex, slow |
| Clogging risk | Low (inclined plates) | Higher (tube settlers) |
| O&M | Easy cleaning and maintenance | More labor-intensive |
3. Sludge Homogenization Mixing Tank
This tank serves two purposes: equalizing the solids concentration of the feed entering the filter press, and acting as a control node for automation.
4. Sludge Dewatering - Automatic Filter Press
This high-performance automatic filter press integrates multiple functions:
● Automatic filtration
● Plate vibration for cake release
● Automatic valve control
● Automatic pump start/stop
● Pressure monitoring
● Fault alarms
Optional features include automatic cloth washing and a automatic drip tray collection system.
Performance characteristics:
● Specialized imported filter plates and fabrics
● Extended pressure-holding time ensures consistent cake dryness
● Short cycle times: ~15 minutes for inorganic sludge, ~30 minutes for organic sludge per batch
● Compact size compared to conventional presses at equivalent capacity, simplifying installation and maintenance
● Lower energy consumption and reduced overall operating costs
Differentiation from Mechanized or Basic Automated Systems
While competing products often achieve only mechanization or basic automation, this system operates with true full automation—approaching intelligent control:
● Sensors throughout the system monitor operational status and return real-time parameters.
● Adjustable system parameters (more than 10 items), including feed pressure, vibration duration, and more.
Smart cycle termination (instead of fixed filtration time):
● - For models with liquid level probes: Probes in the drain channel detect liquid flow rate to determine when to open the plates.
- For models with pressure-hold settings: High and low pressure limits are set. Only time spent within this pressure range counts toward the required hold time. The plate opening is triggered only after the specified pressure-hold duration is achieved, ensuring consistent cake moisture content from cycle to cycle.
Conclusion
The combination of a Lamella clarifier and an automatic filter press - preceded by coagulation, flocculation, and sludge homogenization mixing - provides a highly efficient, compact, and reliable solution for stone processing wastewater treatment. This system maximizes water reuse, minimizes waste disposal costs, and significantly reduces environmental impact.