Location: Michigan, USA
OEM Partner: Belmar Technologies
Application: Direct Filtration – Metal Recovery
Product: B-SMART® Eco system
Capacity: 456 – 528 m3/day
Membrane: 8 mm, PVDF, backwashable
A factory in mid-western United States specializes in the recovery of titanium from waste streams collected from other factories. The company then treats and processes the recovered titanium. Afterwards makes it available for reuse in other applications.
The metal recovery process is inherently complex and involves multiple stages. It typically includes several pre-treatment steps to separate particles ranging from approximately 1 mm down to 150 microns in diameter. Given the high value of titanium, additional advanced technologies are required to maximize recovery. Beyond titanium recovery, the process also ensures compliance with discharge limits.
Belmar Technologies needed to design a robust and adaptable ultrafiltration (UF) system that could keep up with the high-solids streams and conditions of this demanding process, while minimizing energy consumption, membrane fouling and clogging. The total suspended solids (TSS) of the feed stream was between 1,000 – 2,000 mg/L, thus rendering hollow fiber membranes as incapable of handling the load and ceramic membranes as too expensive and energy demanding.
The Berghof Membranes B-SMART® Eco system was the ideal solution for this application. The unit was designed as 3 single loop skids, each loop equipped with three tubular UF membrane modules plus one dummy module for future expansion.
Because of the nature of the flow stream, the UF skid utilizes PVDF backwashable membranes in a feed-and-bleed configuration. The B-SMART® Eco feature automatically sets system parameters to run at the lowest possiblecrossflow velocity during normal operation, and then adjusts when it detects a higher fouling or plugging potential. This ensures that the system does not use additional energy beyond what is necessary for optimal performance.
Figure 2 is a representation of the recovery process which begins with the waste titanium entering the crushing machine to convert the metal pieces into smaller particles, using water to control the temperature within.
The particles are then sent to a rinsing machine. The titanium is then separated from the liquid stream which is sent to the same mixing storage tank as the wastewater from the crushing machine. Once the liquid waste passes through a series of strainers ranging from 150 – 200 micron, then stream is directed to thee titanium precipitation chambers. In each chamber, necessary adjustments are made to control the pH levels to within a range that optimizes titanium precipitation.
The sludge from the precipitation process is separated and it is then routed to a sludge treatment system and filter press. The wastewater with colloids, however, is sent to the tubular ultrafiltration system from Berghof Membranes. As shown in figure 2, the 3 single loop UF skids further recover material (concentrate) that is then directed to the sludge treatment system.
Figure 3 shows the initial titanium waste that enters the process through the crushing machine (figure 4) while Table 1 shows the general operation parameters.
| Flux | 40 – 45 LMH |
|---|---|
| TSS | 1,000 – 2,000 mg/L |
| Design crossflow velocity | 2.0 – 4.0 m/s |
| (3.0 m/s avg. during filtration process) | |
| Membrane surface area | 481 m2 (641 m2 with expansion) |
This case study shows how direct filtration with tubular ultrafiltration membranes enables efficient recovery of valuable metals from industrial wastewater while optimizing energy use and process reliability.
This case study shows how tubular UF technology enhances wastewater treatment and enables efficient recovery of valuable metals in the microelectronics industry.
