Rotowinner™ – Continuous Electrolysis Technology Development

Rotowinner™ – Continuous Electrolysis Technology Development

In 2013 the idea of inventing and developing a continuous electrolysis machine was first incepted by Dr Ryno Pretorius. While completing his PhD degree in Chemical Engineering at the University of Pretoria, Ryno spent his free time inventing and building the technology that would later become known as the Rotowinner™. In 2014 the benchtop prototype for a continuous electrolysis device was designed and built. The device in its current working form was first tested in 2015, thus successfully proving the concept of continuous electrolysis specifically for hydrometallurgical electrodeposition a.k.a. electrowinning. Dr Ryno founded Free Radical Process Design (Pty) Ltd in 2015 to serve as the commercial vehicle for his inventions and patents. 

With the concept proven, the University of Pretoria applied for a patent in 2016. Dr Ryno applied for seed funding from the Technology Innovation Agency (TIA). TIA granted the funds, promoting the development of a more elaborate continuous electrolysis device. The scaled prototype was completed in 2017 and the technology performed well in testing. The device tested well, proving the concept beyond a doubt, and confirming continuous electrolysis and the Rotowinner™ design concept as being superior to batch or semi-batch electrolysis. 

The Rotowinner™ concept was voted the runner-up for best invention at the SA Innovation Summit 2017 inventors garage. In 2018, Dr Ryno assembled a business development team to investigate market entry strategies and the formulation of a clear vision for the business and its expectations. The Rotowinner™ technology offers improved production throughput at a reduced capital expense compared to standard electrowinning technologies. FRPD’s team also identified a niche in the market to utilise electrowinning as an ion separation technology; thus enabling process stream purification. FRPD’s team used the benchtop pilot to demonstrate the technology to industry professionals and gained formal expression of interest from most of the companies that viewed the technology.

Based on the results of the demonstration and feedback from the industry stakeholders, the University of Pretoria granted FRPD exclusive rights to commercialise the technology. FRPD applied and received additional funds from Technology Innovation Agency (TIA) to develop the technology further toward the end of 2019. 

With the funding secured, FRPD approached a strategically relevant metals refinery located in Gauteng, South Africa who agreed to a formal cooperation agreement with FRPD. FRPD collected leachate samples from the electrowinning circuit and proceeded to produce copper in a laboratory environment. The tests were successfully concluded and the metals refinery agreed to further testing in an operation environment. The FRPD team has since produced cobalt, nickel and zinc under laboratory conditions.

During the technology development process, the team started calling the device the Rotowinner™. FRPD applied for a Trademark which was awarded in 2020. 

At the time of writing this post, FRPD has completed the design drawings of the Rotowinner™ and procurement and construction of the pre-commercial pilot plant is set to begin in early 2021. FRPD aims to achieve the following milestones before the end of 2021:

  • Procurement and construction of the pre-commercial pilot plant.
  • Test the pre-commercial pilot plant in an operational environment using industrial electrolyte.
  • Complete design for a commercial containerized system and refine financial data based on commercial testing.
  • Initiate production, marketing and expand business operations.

FRPD develops pilot plants and we offer process engineering services. Contact us through our website to find out more. 

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  • Dr Ryno Pretorius
  • Beyers Hauptfleisch
  • Fritz Ferreira
  • Maarifa Kidoge

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