BHS-Sonthofen supplies pressure plate filter for the recovery of precious metals to Indaver NV

Chemical- and pharmaceutical production plants produce waste streams containing valuable precious metals. A large proportion of these liquids originate from reactions based on homogeneous precious metal catalysts. After the production process, the precious metals remain diluted in the aqueous- or solvent-based suspensions. Direct disposal of said waste streams, is both ecologically and economically disadvantageous for the producers. Indaver NV has, in collaboration with BHS-Sonthofen, developed an elegant solution to reduce the waste volume, enable reuse of the precious metals and recycle the solvents when possible (3R principle). The precious metals are recovered by collecting and treating the liquids in the Inda-MP plant.

To separate the rare metals that occur in suspension or sediment form in the liquid streams, the liquid solvent streams are processed in an upstream reactor. The BHS pressure plate filter is used for the subsequent recovery of the precious metals. The particular challenge here is the processing of many different types of hazardous and explosive input streams with a wide range of viscosities. The pressure plate filter works discontinuously and is used for cake-forming solid-liquid separation in suspensions with a low solid content and poor filterability. It is a compact, fully automatic unit that allows maximum flexibility.

The entire filtration process takes place under pressure in a closed, gas-tight system. This enables the pressure plate filter to be used even under strict safety or containment requirements. Products can also be processed in an inert atmosphere. The fully encapsulated filter and its components are designed for an operating pressure of 6 bar and comply with European ATEX regulations. Due to the high corrosiveness, all parts in contact with the product are made of super-duplex steel or Hastelloy.

In order to protect the end product from external contamination and at the same time protect the operators from contact, a discharge system specially tailored to the process and the system was designed in collaboration with Indaver. This system is based on an endless liner and a special emptying device.