The Vertical Pressure Filter (VPF), introduced by Metso Outotec, optimises the removal of suspended solids before alumina hydrate precipitation, reducing entrained particulate concentrations in sodium aluminate solutions to a level of only a few milligrams per litre
The VPF is part of the company’s portfolio of Planet Positive products and is designed to improve sustainability and overall process performance as well as decreasing costs.
The automatic cloth cleaning and cake discharge steps at the end of each filtration cycle ensure maximum filtration time in subsequent cycles. The VPF includes sequence control for multiple filters and can be fully integrated with the plant’s automation system.
Thanks to its smart design, the VPF is safe and cost efficient to operate and maintain. The filter vessel remains securely closed and sealed during filtration, cloth cleaning, and cake discharge, and has easy access for inspection and maintenance. Filter leaves can be easily replaced as single units with the use of an overhead crane.
The compact design of the filter minimises the space needed and therefore reduces the associated construction costs. Downtime needs for cloth cleaning and cake discharge are minimised, thanks to the extended filtration cycle of up to 18 hours. In addition, the efficient cloth cleaning system maximises cloth lifetime. The filter doesn’t have any moving parts, so maintenance cost per cubic meter of produced filtrate and wear part consumption is low.
Key benefits:
• High-quality filtrate
• Fully automatic cloth cleaning and cake discharge
• Increased safety during operation and maintenance
• Reduced CAPEX and lower operating and maintenance costs
• Based on proven technology.
Manas Dutta Gupta, senior product manager, Metals & Chemical Processing at Metso Outotec, commented, “Filtration of supersaturated aluminate liquor is a vital step in the production cycle to meet the required quality standards for smelter grade alumina (SGA). The Metso Outotec VPF is based on proven technology that provides superior solids removal along with easy and safe operation. The VPF nicely complements our wide offering in alumina technology.”
