ClearStream Paste Thickeners
Engineered for Performance, Stability, and Water Recovery
Proven Design Expertise
ClearStream’s paste thickener designs embody decades of learning and refinement. Since the introduction of paste thickening in the minerals market in the early 1990s, our team has continuously optimized designs to meet the evolving challenges of mine tailings management. What are your process goals?Whether your target is specific yield stress, solids concentration (wt%), or rheological control, ClearStream designs and delivers thickeners tailored to meet your operational objectives.
The Challenge: Efficient Paste Thickening
Paste thickeners offer significant water recovery and safer tailings management—but they also can cause operational challenges. Common industry pain points include:
Inconsistent feed conditions
High variability in the tailings feed (solids concentration, particle size distribution, and mineralogy, especially clay content) is a major pain point.
- Impact on Capacity/Flow: This variability makes it difficult to maintain a stable operation, leading to poor settling rates and reduced throughput (capacity) of the thickener.
- Impact on Flow/Product: Changes in feed can cause large fluctuations in the rheology (viscosity and flow properties) of the underflow, making pumping and transport unpredictable.
High viscosity and pumping demands
Paste underflow has a high yield stress and is non-Newtonian, meaning it requires significantly more energy and specialized, expensive positive displacement pumps (as opposed to simpler centrifugal pumps) for transport. This higher viscosity limits achievable flow rates.
Rheology Sensitivity
Achieving a consistent, pumpable paste requires extremely tight control over the final solids concentration and rheology. Small variations in feed or flocculant can cause the paste to be too thick (leading to rake bogging) or too thin (which defeats the purpose of paste disposal). This sensitivity makes capacity highly vulnerable to operational upsets.
Integrated Design Complexity
The entire paste system—thickener, pumping system, and disposal site—must be designed as one integrated, rheology-based system. A design or operational conflict in one area (e.g., aiming for a very high-angle-of-repose at the disposal site) often increases the pumping difficulty and cost/risk of the thickener operation.
High Operating Costs
While the long-term benefit of reduced environmental risk and water recovery is high, the immediate OPEX (Operational Expenditure) is higher due to greater energy consumption for pumping and the high cost/maintenance of specialized equipment.
ClearStream’s Optimized Approach
ClearStream’s design philosophy directly addresses the flow and capacity constraints common to paste thickening. Each ClearStream paste thickener is optimized to:
- Stabilize feed variability with advanced flocculation and mixing controls.
- Maximize settling performance through deep bed volume and optimized floor slope.
- Reduce mechanical stress with heavy-duty rake drives and low-profile arms.
- Deliver consistent rheology for predictable pumping and discharge.
Our systems are designed as integrated, rheology-based solutions—ensuring the thickener, pumping system, and tailings disposal site operate in harmony.
Critical Features That Set ClearStream Apart
Paste-type thickeners differ fundamentally from high-rate thickeners. ClearStream integrates key design features proven to enhance performance:
- Steep floor slopes for rapid solids consolidation.
- Large bed volume to provide dewatering residence time.
- Pickets and low-profile arms to handle dense material.
- Heavy-duty rake drives built for deep, high-torque operation.
Each feature is individually optimized for your project’s goals. While other designs may appear similar, even small variations in these features can mean the difference between success and poor performance.
Significant Benefits in Mining Operations
ClearStream Paste Thickeners improve efficiency and safety across multiple process applications:
ClearStream Paste Thickeners produce a high-yield-stress underflow that can be safely and effectively surface stacked. Field studies demonstrate stack heights exceeding 30 meters with long-term stability. This approach minimizes the footprint of tailings storage facilities, reduces water loss through evaporation and seepage, and significantly lowers the risk of dam failure or environmental contamination—making it a preferred solution for mines focused on sustainable closure strategies.
When integrated into counter-current decantation (CCD) circuits, ClearStream Paste Thickeners reduce the volume of wash water required by up to 40%. By delivering a higher-density underflow, the downstream washing stages handle less liquid, which not only improves metal recovery but can also reduce the total number of CCD stages required. The result is a smaller process footprint, lower water demand, and decreased reagent use—improving both efficiency and operating costs.
Paste thickeners are highly effective in preparing slurry for filtration. ClearStream designs deliver consistent, high-solids feed that optimizes filter performance, shortening filter form time by approximately 40%. This means faster cycles, higher throughput, and less wear on filter media. Improved dewatering before filtration also reduces energy use in subsequent drying processes, directly improving plant productivity.
Paste thickening technology enhances the efficiency and flexibility of backfill operations. ClearStream systems can provide a dense, pumpable paste suitable for underground backfill, while also allowing tailings to be temporarily surface-stacked during backfill downtime. This dual capability helps operators manage fluctuations in mining schedules and maintain compliance with environmental storage regulations—all while maximizing water recovery for reuse in the process plant.
In pressure oxidation and leaching circuits, water content directly affects reagent consumption and downstream efficiency. By delivering a thicker, low-water underflow, ClearStream Paste Thickeners reduce the dilution entering autoclaves. This results in lower acid consumption, improved reaction kinetics, and reduced heating requirements. Over time, this translates into measurable reductions in operating costs and chemical demand.
ClearStream Paste Thickeners enable controlled subaqueous deposition of tailings, where high-yield-stress material resists resuspension even under water. This characteristic allows operators to safely transition from conventional slurry ponds to more stable, stackable deposits below the waterline. The approach reduces turbidity, prevents environmental release of fine particles, and extends the life of existing tailings impoundments—all while maintaining compliance with strict water quality standards.
Thickening solutions for challenging slurry conditions.
3D Models of Every Project
ClearStream develops a detailed 3D model for every unit manufactured, ensuring accurate fit-up and seamless integration with site-specific layouts. These models also serve as a valuable tool for operator training and system familiarization, providing clear insight into unit design and operation.
Clients are provided access to the 3D models, allowing them to view and manipulate the equipment from their own office or facility. This capability enables operations and maintenance personnel to virtually inspect the unit, plan maintenance activities, and understand internal components—without draining the tank or interrupting operation.
Have A Process Problem? Need A Solution?
Our engineers will ensure you get the support needed to solve your process problems.