For quartz sand wet processing lines, the combined hydrocyclone + high-frequency dewatering screen system is widely used to reclaim fine quartz particles lost in washing overflow. The recovery rate is size-dependent, which is the most critical point for quartz sand production.
Typical Recovery Rate Range (Quartz Sand)
- +75 μm (+200 mesh) quartz fine sand: 85% ~ 92% under stable optimized operation; well-tuned systems can reach 90–95%
- +106 μm (+140 mesh) / +150 μm (+100 mesh): 90–95% recovery, easier to capture
- 50–75 μm ultra-fine quartz: Recovery drops sharply to 60–80%. Sub-50 μm particles mostly escape through cyclone overflow and cannot be economically recovered by this setup.
For your target fractions (40–80, 80–120, 120–200 mesh quartz sand), the system can recover 88–92% of +75μm fine quartz sand from the washing slurry under good operating conditions.
Definition Note
Recovery rate here means: mass percentage of target fine quartz particles in the feed slurry that are captured and discharged as solid product from the dewatering screen.
Fines passing through dewatering screen mesh will return to the slurry tank and circulate back to the hydrocyclone, which improves overall system recovery.
Key Factors That Reduce Quartz Sand Recovery
- Slurry feed concentration: Best range 25–35% solids. Too dilute reduces cyclone underflow density; over-concentrated slurry causes poor classification and carries fine particles into overflow.
- Cyclone pressure: Standard operating pressure: 0.12–0.25 MPa. Low pressure weakens centrifugal separation; excessive pressure increases wear and raises overflow fine loss.
- Apex / spigot wear: Quartz is highly abrasive. Worn cyclone apex changes underflow density, leading to either too watery underflow (fines wash through screen) or rope discharge.
- Clay / slime content: High clay content increases slurry viscosity, trapping fine quartz and sending them out via overflow, dropping recovery by 10–20%.
- Dewatering screen mesh selection: PU fine mesh must match the cut point. Over-large mesh lets fine quartz leak back to slurry tank.
Typical Finished Sand Moisture
After dewatering screen treatment, recovered quartz sand moisture is normally 12–16%, suitable for stockpiling and further drying.
Practical Optimization Tips
- Use polyurethane-lined hydrocyclone and PU dewatering screen panels to resist quartz abrasion and maintain stable cut point.
- Install closed slurry recirculation tank for particles leaking through the dewatering screen.
- Control feed slime content; pre-desliming is required if raw quartz carries high clay.
- Monitor cyclone underflow shape: a “spray discharge” is ideal; rope discharge indicates worn spigot or wrong concentration.
For your quartz sand project targeting fractions above 200 mesh (+75μm), the hydrocyclone + dewatering screen system delivers 85–92% fine sand recovery, with optimized steady-state performance at ~90%. Recovery falls significantly for particles finer than 75 μm.
