Classified Expanded Perlite

The MinaFil series consists of perlite filter aids produced by expanding perlite ore, followed by milling and air classification.

Production begins with the rapid heating of perlite ore with controlled particle size distribution and moisture content in an expansion furnace. During heating, the glass structure softens and the water within it turns to steam, causing the particles to expand into a lightweight, cellular structure. Ore selection, feed rate, furnace temperature and residence time are controlled to produce material suitable for subsequent milling and classification.

Following expansion, the material undergoes controlled milling and air classification. These processes produce different grades with the required particle size distributions and permeability characteristics.

MinaFil is produced exclusively at our Viguera facility in Spain. Integrated process control enables key production variables to be monitored and adjusted throughout expansion, milling and classification, supporting consistent particle size distribution, permeability and product quality.

MinaFil products are used to separate suspended solids from liquids and improve liquid clarity. During filtration, irregularly shaped perlite particles form a porous filter cake containing microscopic flow channels. This structure retains suspended solids while allowing the liquid to pass through.

In precoat applications, MinaFil forms a permeable layer on a support surface, such as filter cloth or a metal screen, before filtration begins. This layer reduces the blinding of the support surface by fine solids and facilitates cake removal at the end of the filtration cycle.

In body feed applications, MinaFil is added to the liquid to be filtered. As solids accumulate during filtration, it helps maintain the porosity and permeability of the filter cake. Precoat and body feed methods can be used separately or together, depending on process requirements. The appropriate grade and dosage are selected according to the liquid’s properties, suspended solids content, target clarity and flow rate.