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APMG Plastics Polypropylene Tanks for Precious Metals Recovery Process

A prominent global player in precious metal refining has again chosen APMG Plastics for its expertise in designing and manufacturing specialised equipment. Following the successful collaboration on a 12-metre-tall fume scrubber system, the company returned to APMG to design and install polypropylene tanks crucial to its metal recovery processes.

The decision to re-engage with APMG Plastics was driven by the positive outcomes and reliable solutions delivered in the past collaboration, highlighting the client’s trust in APMG’s capabilities.

The tailored design of the polyethene tanks and the integration of cutting-edge fume extraction technology reaffirms the commitment to safety, excellence and innovation that defines the partnership between the two companies.


APMG Plastics has applied its experience and expertise in designing and fabricating specialised processing and extract equipment for a global metals company. Following a successful collaboration on a large fume scrubber system, APMG Plastics designed, fabricated, and installed custom plastic tanks crucial to its metal recovery processes. The tanks, customised for barrel rig systems, handle acids and rinse agents and incorporate advanced fume extraction technology for operator and environmental safety. The project demonstrates APMG Plastic’s commitment to innovation and sustainability for its clients.

The Brief

The primary objective was to design and implement a reliable and efficient chemical-resistant polypropylene tank system for the precious metals recovery process. The client’s utmost priority is the safety of its team, so these tanks must facilitate the extraction processes while assuring the safety of workers. The effective handling of the acidic fumes generated during the reactions is crucial.

Tank Specifications

Rectangular Tanks

These are chemical-resistant poly tanks designed for a barrel rig system. They can handle a volume of either acid, which breaks down the platinum coating on various components, or a rinse agent.

The components are held within a barrel-type enclosure, lowered into the acid tank and rinsed. The barrel is designed to rotate while submerged within the acidic reservoir, allowing the reaction to occur.

Each tank incorporates lip extraction hoods on either side. These are purposely designed as part of the tank structure to provide a seamless unit. This technique provides the appropriate extraction across each tank’s surface to remove the acidic fume from the workspace.

Before the acidic fumes exit the atmosphere, they pass through one of APMG’s counter-current packed-bed fume scrubbers, where the contaminated air is treated and neutralised. APMG Plastics’ heavy-duty ‘H’ series directly driven forward curved fans power the extraction.

Design and Functionality

  • Customised for barrel rig systems.
  • Able to handle acid and rinse agents for breaking down platinum coatings.
  • Incorporates a barrel-type enclosure for component containment.
  • Allows for immersion, rotation, and extraction processes.

Safety Features

  • Lip extraction hoods on both sides of the tank.
  • Purpose-built design to ensure a seamless unit.
  • Calculated extraction efficiency for removal of acidic fumes.

  Fume Extraction System

  • Utilises APMG’s counter-current packed bed fume scrubbers.
  • Neutralises and treats contaminated air before release.
  • Powered by APMG’s heavy-duty ‘H’ series directly driven forward-curved fans.

Circular Tanks with Lids

Again, these are chemical-resistant polypropylene storage industrial tanks. Each tank has been specifically designed to allow for moveability using a forklift truck, featuring cut-outs at the base to accept the forks. The internal base is formed as a conical shape to facilitate complete drainage of the tanks. This is controlled with a polypropylene ball valve and pipework configuration on the underside of the tanks.

The industrial tanks have been fitted with bespoke polypropylene lids. To contribute to the overall safety and efficiency of the operation, these lids are designed to allow the operator to rotate them. They can provide an opening of either one quadrant or half of the tank diameter, maintaining the position of the extract point. These extract points are connected to the duct system to remove any fumes present.

Design and Functionality

  • Chemical-resistant polypropylene construction.
  • Facilitates mobility using forklift trucks with cut-outs for forks.
  • Internal conical shape for complete drainage controlled by a ball valve.
  • Fitted with bespoke lids for safe opening.

Lid Features

  • Rotatable design for adjustable opening size (one quadrant or half tank diameter).
  • Maintains the position of the extract point for safe, efficient fume removal.

Safety and Efficiency

  • Extract points are connected to a ductwork system to purge fumes.

Why Choose Polypropylene?

Polypropylene is a suitable and cost-effective material for handling acidic solutions due to its exceptional chemical resistance and durability. Its inherent resistance to a wide range of acids, including strong and corrosive ones, makes it ideal for applications involving precious metal recovery processes using acidic solutions.

Its ability to withstand the corrosive nature of acids ensures equipment longevity, reducing the need for frequent replacements and maintenance. Moreover, its cost-effectiveness compared to alternative materials, combined with its versatility in fabrication, makes polypropylene a practical and reliable choice. It provides a balance between performance, longevity, and economic efficiency.

APMG’s expert engineers and plastics fabrication team have decades of experience in designing, fabricating, installing, and commissioning polypropylene fume extract systems, including wet scrubbers, fans, and ductwork.


The installation of these tanks involved meticulous integration into the precious metal recovery process and fume extract system.

The APMG Plastics team designed, fabricated, and installed the existing extract system three years ago. This new tank arrangement was devised to be fully compatible with the already successfully functioning counter-current packed bed fume scrubber system with a mist eliminator and 12m high, GRP-coated polypropylene wet scrubber tower.

The polypropylene ductwork from the tanks to the external ducting was fabricated by APMG Plastics.

Our expert installation team fitted and commissioned the new tank system. The rectangular tanks were positioned to accommodate the barrel rig system, and the circular tanks offered easy positioning with their fork-lift-friendly design.

A Successful Project

By returning to APMG Plastics for the latest investment in its plant, our client has recognised us as a trusted and innovative partner which provides advanced solutions for specialised applications.

The poly tanks have demonstrated exceptional chemical resistance, durability, and functionality in handling the recovery process. The integrated fume extraction system, featuring APMG’s advanced wet scrubbing technology, ensures a safe working environment by neutralising and treating acidic fumes before release.

Implementing the tank upgrade has significantly contributed to the efficiency and safety of the precious metal recovery process. These tanks’ smart, tailored design and advanced fume extraction technology reflect a commitment to innovation and sustainability in extracting precious metals from industrial scrap components.