Lessons from Fine-Solid Recovery That Matter in Hydrometallurgical Slurry Separation

As the global titanium dioxide industry moves toward higher-value, more advanced production, large-scale manufacturing of ultrafine titanium dioxide—with particle sizes ranging from 10 to 50 nm—continues to face a critical challenge: how to retain nanoscale particles while achieving efficient washing.

JIUWU High-Tech’s proprietary polymeric tubular membrane system addresses this challenge through verifiable performance metrics and proven field application.

Cross-Flow Filtration for Soluble Impurity Removal

The tubular ultrafiltration system operates in cross-flow mode.

Under pressure, the titanium dioxide slurry flows along the inner surface of the membrane tubes. Water and soluble impurity ions pass vertically through the membrane wall and are discharged as permeate, while the titanium dioxide particles are retained within the tubes and continue circulating.

By continuously introducing demineralized water and removing wash water, the system effectively reduces soluble impurity ions in the slurry while minimizing the loss of valuable ultrafine titanium dioxide particles.

Technical Breakthroughs That Address Industry Challenges

For ultrafine titanium dioxide slurries characterized by strong acidity and high ionic concentrations, JIUWU’s tubular membrane system delivers three key advantages:

Precision Separation

With a designed filtration precision of 0.02 μm, the system achieves a verified retention rate of up to 99.9% for nanoscale titanium dioxide particles while maintaining a high membrane flux.

Enhanced Acid Resistance

The system uses acid-resistant material combinations designed for continuous operation in highly acidic environments, including pH levels of 0.5–1. Under suitable operating conditions, the system can operate continuously for more than 8,000 hours.

Stable Performance

Across multiple washing batches, the system maintains stable membrane flux and supports longer cleaning intervals, helping improve operational continuity and process consistency.

Demonstrated Performance Across Multiple Applications

Compared with conventional technologies such as diaphragm filter presses and vacuum leaf filters, tubular membrane washing offers significant advantages in ultrafine titanium dioxide processing.

1. Faster Washing and Higher Processing Efficiency

Cross-flow filtration promotes more effective separation between soluble impurity ions and titanium dioxide particles.

As a result, washing time can be reduced by approximately 8–10 times compared with conventional processes, significantly improving overall processing efficiency.

2. Reduced Water Consumption

Depending on the customer’s washing requirements, the tubular membrane process can control the washing-water ratio within 10–30 times.

This can reduce water consumption by approximately 50% compared with conventional vacuum leaf filtration. For a plant producing 1,000 tonnes of high-end ultrafine titanium dioxide annually, annual water savings can reach approximately 150,000 tonnes.

3. Minimized Product Loss and Improved Economics

Due to insufficient filtration precision, conventional diaphragm filter presses may result in a loss rate of 5–8% for nanoscale ultrafine titanium dioxide particles.

The tubular membrane system can achieve a particle retention rate of up to 99.9%, helping preserve product yield and improve the economic performance of the washing process.

4. Process Flexibility and Smaller Footprint

The system’s modular design can reduce the required footprint by more than 50% compared with conventional processes.

This makes it particularly suitable for brownfield plant upgrades, retrofit projects, and new facilities with limited available space.

Project Validation

The data below represents nearly one month of continuous on-site operation from a 500-ton-per-year ultrafine titanium dioxide project.

After repeated washing cycles involving multiple batches of ultrafine titanium dioxide slurry, both membrane flux and washing efficiency remained stable, with no significant downward trend observed.

This project demonstrates JIUWU High-Tech’s practical engineering experience in handling complex chemical slurries and delivering continuous solid–liquid separation at industrial scale.