Thickener Overflow Water Tank System with Leak-Proof Design
Basic Info Overview
Thickener Overflow Tank
Clarifier Thickener Overflow Water Tank- Stored Material: Thickener Overflow Water, Process Water, Recycled Industrial Water, Slurry-Influenced Water, Settling Tank Effluent
- Number of Silos: 4 Sets
- Silo Type: Spiral Steel Tank
- Silo Size: Φ25m × H8.62m (2 Sets); Φ10m × H8m (2 Sets)
- Silo Diameter: 25m
- Silo Height: 8.62m
- Maximum Single-Silo Capacity: Approx. 4,231 m³
- Total Storage Capacity: Approx. 9,714 m³
Application & System Configuration
Overflow Water Storage Tank 
Industrial Overflow Water Tank System- Thickener Overflow Collection System: discharge pipeline, collection channel basin, sediment pre-treatment separation unit.
- Process Water Transfer & Storage System: slurry clarification transfer pumps, buffer tanks, hydraulic balance control system.
- Solid-Liquid Separation Interface System: sediment settling enhancement units, interface return sludge pipeline, enhancement of clarification.
- Corrosion & Anti-Leakage Protection System: anti-corrosion coating, sealing of plates, monitoring of leakage control.
- Water Quality Monitoring & Control System: turbidity sensors, level radars, pH SCADA interface.
Industry & Target Clients
- Applicable industries: Mining Industry, Mineral Processing, Metallurgical Processing, Industrial Wastewater Treatment, Water Recycling Systems
- Target Clients: Mining Companies, Mineral Processing Plants, Metallurgical Enterprises, EPC Water Treatment Contractors, Industrial Environmental Engineering Projects
Thickener Overflow Water Storage Characteristics
| Material | Typical Bulk Density | Storage Characteristics |
|---|---|---|
| Thickener Overflow Water | ~1.00 t/m³ | Contains fine suspended solids. For sediment control and anti-settling in storage, there must be hydraulic stability in storage tanks. |
| Process Water | ~1.00 t/m³ | Recycled water from industrial processes. Requires stable quality and corrosion resistant storage and control systems. |
| Slurry-Influenced Water | 1.05–1.20 t/m³ (equivalent mixture) | Contains sediment fine particles and is prone to sedimentation, thus requires agitation or circulation. |
| Recycled Industrial Water | ~1.00 t/m³ | Requires stable physicochemical conditions and must have a tight seal to control loss of water quality and to avoid contamination. |
| Settling Tank Effluent | ~1.00 t/m³ | Partially Clarified water and requires final polishing and monitoring prior to reuse or discharge. |
Engineering Challenges in Industrial Mining Overflow Water Storage and Recovery Systems
Industrial mining and mineral processing plants generate about 30 – 65% of their total process water as thickener overflow water. To avoid operational inefficiencies, thickener overflow water needs to be captured and reused. Therefore, in closed-loop water systems, a thickener overflow water tank is a critical buffer component that determines the water recovery and hydraulic stability of the plant.
Industrial Wastewater Storage Tank
In modern EPC mining projects, process water recovery systems are designed to reuse 70 – 90% of the water, therefore significantly reducing the need for freshwater. However, the tank design is challenged by variations in the concentration of solids (which may range from 200 – 2,000 mg/L suspended solids) because of sedimentation and corrosion control. Thus, an overflow water storage tank must be designed to withstand variations in slurry conditions while achieving hydraulic stability and durability.
For mining and industrial applications requiring flexible storage expansion, a modular silo system approach can provide adaptable structural solutions that support efficient installation and long-term operational reliability.
Integrated Sealing and Corrosion Control Design Logic for Steel Thickener Overflow Water Tanks
A corrosion resistant storage tank for water in mining applications must be designed to withstand both chemical and mechanical deterioration. In a typical concentrator plant, overflow water may contain chlorides and sulfates in significant amounts that, in the absence of mitigation, may cause severe corrosion.
Integrated Corrosion Protection & Design Basis for Thickener Overflow Water Tanks
| Design Layer | Engineering Parameter | Typical Range / Specification | Engineering Function |
|---|---|---|---|
| Water Chemistry Severity | Chloride content | ≤ 500 mg/L | Corrosion rate and coating selection are determined. |
| Water Chemistry Severity | Sulfate content | ≥ 1,000 mg/L | Accelerates localized corrosion. |
| Steel Structure Design | Corrosion allowance | 1.5–3.0 mm | Compensates for the loss of metal over time. |
| Internal Protection System | Lining thickness (epoxy/rubber) | 2–5 mm | Prevention of chemical attacks. |
| Electrochemical Protection | Cathodic protection potential | ≤ -850 mV (Cu/CuSO₄) | Protection against electrochemical corrosion. |
| Hydraulic Design Condition | Water head variation | 3–12 m | Determines how stress is distributed across the walls. |
| Structural Scale | Tank diameter | 20–60 m | Determines how thick the shell needs to be and how much reinforcement is needed. |
| Process Stability Control | Flow residence time | 4–12 h | Guarantees that overflow quality is stable. |
It is clear that to design an industrial wastewater storage tank for thickener overflow service, a combination of structural, hydraulic, and material engineering is needed. The design cannot focus solely on steel selection. It also requires relevant design for linings, protective coatings, and corrosion allowance as an integrated system.
A reliable turnkey silo solution provider can support customized material engineering and fabrication strategies for industrial storage projects where corrosion resistance and process requirements must be integrated.
Material and Protection System Engineering Strategy
- Corrosion allowance. Typically between 1.5 and 3.0 mm, based on the aggressiveness of water chemistry.
- Linings. Epoxy and rubber are used to reduce steel exposure.
- Cathodic protection. Achieved by maintaining a steel potential of less than -850 mV (Cu/CuSO₄ reference).
These design layers ensure reliable performance of the tank in highly variable process water chemistry typical of mining operations.
Hydraulic and Structural Load Interaction Considerations
- Water head design variation: In large overflow systems, head designs are typically between 3 and 12 meters.
- Tank diameter variations: In industrial mining plants, tanks can range from 20 to 60 meters in diameter.
- Flow residence time: To aid even distribution of suspended solids, a residence time of 4 to 12 hours is optimal.
Inadequate hydraulic and structural design integration leads to failure of coatings and washout in high abrasion areas due to stress concentrations.
These design layers ensure reliable performance of the tank in highly variable process water chemistry typical of mining operations.
Corrosion and Abrasion Dynamics of High Solids Overflow Water
During thickener overflow, high solids slurries can reach damaging wear rates in slurries at the inlet zones.
- In the absence of protective coatings, a typical wear rate due to slurry erosion can be in the range of 0.1 to 0.5 mm/year in unprotected steel areas.
- An approximate concentration of solids in the slurry is between 0.5 and 3.0% in the thickening process depending on the efficiency of the upstream thickener.
- Typically, localized turbulence leads to an increase in wall shear stress of 20 to 40% at the point of inlet.
When hydraulic and abrasion controls are not properly implemented, corrosion and abrasion will lead to serious degradation of structures in a short time.
Control of Sedimentation and Stratification in Wide Diameter Tanks
Settling of particles due to stagnant flow can be a problem in large industrial systems of overflow tanks. For tanks with a diameter greater than 40m, stagnant zones cause flow velocity differences of less than 0.03m/s.
- For suspended particles, settling velocity can be in the range of 0.2 to 1.5mm/s
- Short-circuiting of a system can be a problem if the tank inlet and outlet are misaligned by more than 30 degrees.
- The thickness of stratification layers in the tank can be in the range of 0.5 to 1.2m
The use of strategically designed flow distribution and internal baffle systems in tanks is one way to help limit the effects of the above.
Flow Distribution and Short Circuiting Design
Good flow distribution design will eliminate dead zones and ensure consistent hydraulic residence time.
- The use of baffles can help provide flow consistency within the tank up to 25 to 45%
- The inlet to outlet hydraulic spacing is suggested to be 0.6 to 0.8 of the tank diameter.
- In a multi-feed system, the efficiency of mixing can be improved through recirculation by 30%
Sedimentation in a tank system can be controlled through the proper design of tank hydraulics.
A spiral rolled steel silo design concept can also be applied in industrial storage engineering where continuous structural forming and space-efficient fabrication are required. The use of strategically designed flow distribution and internal baffle systems in tanks is one way to help limit the effects of the above.
Multi Tank Design and Redundant Systems
Modern designs of process water recirculation systems in the mining industry do not rely on a single tank. Multiple tank systems are employed to provide operational stability and hydraulic redundancy.
In large mineral processing operations, the daily water requirement can be up to 10,000 – 50,000 m³ necessitating multiple storage systems to ensure continuous operations.
- Horizontal balancing deviation control: Flow across all storage tanks remains within ±5%.
- Time to switch tanks: In automated systems, this is typically between 10 mins and 20 mins.
- Level of redundancy: In operational critical mining systems, redundancy is designed as N+1.
Continuous Operation Stability in Water Reuse Systems
- Efficiency of industrial water reuse: In fully optimized systems, this can be as high as 75% to 92%.
- Ratio of buffer storage to throughput: Generally between 15% and 30% of daily water throughput.
- System reliability target: 2 hrs/month downtime in high reliability EPC systems.
- Load balancing: Uniform distribution of load across all tanks.
- Emergency bypass systems: Flow is maintained during the bypass.
- Automated sequencing of valves: Manual interventions are reduced by 40% to 60%.
Reliability of industrial water tank systems in mining is significantly increased by the strategies employed.
Reliability and Operational Safety of Steel Overflow Water Storage Systems
The reliability of the overflow water tank system in the mining water treatment plant impacts both the throughput of the plant and compliance with environmental regulations. The system is designed to retain its structural integrity when exposed to cyclic water pressure of between 0.2 and 1.0 MPa.
Critical engineering safety parameters are as follows:
- Design safety factor: 1.5 to 2.0 for steel structures.
- Seismic resistance: Designed for 0.1 to 0.3g of horizontal acceleration depending on site classification.
- Corrosion allowance: 1.5 to 3.5 mm depending on water chemistry.
- Structural monitoring systems: Strain sensors with an accuracy of ±2 microstrain.
- Leak detection: Leaks are detected when the flow is greater than 0.1 L/min/m².
- Inspection cycles: Every 6 to 12 months for environments with high solids content.
These engineered solutions provide mining industries with Corrosion Resistant Tanks that assure design stability and reliability.
For advanced wastewater management applications, cooperation with a professional wastewater treatment equipment supplier helps ensure that storage systems are integrated with effective treatment and recovery processes.
