Outotec Larox RT & RT-GT Filters

Benefit from true multi-step processing in a single unit. The Outotec Larox® RT (reciprocating tray) horizontal vacuum belt filters use a continuously-moving filter cloth, without the need for a rubber support belt. The cloth is supported by a rigid vacuum tray and the filter is capable of cake washing in both co-current and counter-current modes. The filter handles a wide range of feedstocks and produces high-purity products cost effectively.


  • Separates slurries into filter cake and clear filtrate continuously
  • Washes co-current and counter-current filter cake, delivering best-in-class cake washing with minimal wash liquid consumption
  • Increases dry solids content through mechanically compressing the filter cake
  • Uses hot gas (air, nitrogen, or steam) and infrared energy for thermal drying of the cake
  • Requires very little maintenance with low operating costs
  • Ensures a long cloth life with continuous cloth washing and a patented cloth tracking system
  • Achieves fully automatic operation, not just automation of function, eliminating the need for constant supervision

Unique Design

The Outotec Larox® RT filter has a unique design that offers discrete multi-step processing of a wide range of products. Steps can include any or all of the following, in almost any combination: multiple washing steps, either co-current or counter-current and with more than one liquid, vibration, hot air drying, cooling, steaming, and mechanical compression. At the heart of the filter is a continuously moving filter cloth that does not require a rubber support belt. Instead, an open grid located in a profiled tray runs the length of the filter and supports the cloth.

A vacuum to separate the solids and liquids is applied to the underside of the cloth. When the vacuum is applied, the forward movement of the cloth pulls the tray with it at the same speed. As the tray advances to a specific point, the vacuum is briefly removed and the tray is returned to its original position. The vacuum is then re-applied and the tray moves again with the cloth.

The ability to carry out multiple washing steps, with each wash filtrate precisely collected into its own receiver, results in a very high level of purity – up to 99.99% or better – with low wash water consumption.

Outotec Larox® RT-GT filters offer all of the advantages of standard RT filters, including co-current or counter- current washing, reflux washing, vibration, all forms of mechanical compression, and either hot gas or infrared drying. These filters are highly configurable and – just like standard RT filters – can be used in many different combinations for multi-step processing.