Rockwell Automation says it is working with Cornish Lithium on a demonstration plant to validate the sustainable production of lithium hydroxide from micaceous granite.
The Cornish Lithium demonstration plant will be controlled by the PlantPAx® modern distributed control system from Rockwell Automation. This DCS provides a single, plant-wide control system and increased flexibility for better business decisions, according to the company.
Phil Hadfield, UK Managing Director, Rockwell Automation, said: “Rockwell Automation has both the technology and domain expertise to support the complex lithium extraction process. We have successfully worked in lithium projects around the world, including Australia, Africa and South America. The integrated architecture from Rockwell Automation provides end-to-end system integration. The systems are designed with scalability in mind, leveraging the new advancements in digital technology.”
Cornish Lithium has licensed an acid-leaching, selective precipitation and crystallisation process developed to create lithium hydroxide from micaceous granite. This process is expected to be more environmentally friendly than the traditional hard-rock process, which usually involves a significant calcination step, where the ore is calcined at 1,000°C, the company says.
The validity of the process has already been tested at a small pilot plant in Australia and proven that it can produce lithium hydroxide monohydrate salt, according to Cornish Lithium. The next step is constructing a demonstration plant at the site in Cornwall. This will be a complete conceptual end-to-end process from the raw material to lithium hydroxide, using all the same equipment employed in a full-scale facility with just one or two changes for scale reasons. This simulation of the actual process will assure all stakeholders and potential customers of the effectiveness of the processing technology on Cornish ore ahead of the construction of a full-scale production facility.
David Moseley, Process Manager, Hard Rock Minerals, Cornish Lithium, said: “Rockwell Automation will play quite a crucial role in what we are doing. We want to try and simulate as much as possible the industrial process control that we might employ at full scale. We are trying to put as much of that into the demonstration plant as possible because it is a complex multi-stage process with lots of recycles – and sequential operation, particularly with filtration, and process control is critical. Rockwell Automation is putting together the process control philosophy based on our instrumentation. This is a series of different process control units that must be coordinated to have a plant that will operate effectively.”
Two plants will be built; one is a mineral concentration plant where raw ore is crushed, milled and separated to create lithium-enriched mica concentrate. The second is the chemical plant, with a hydrometallurgical acid leaching system that produces lithium sulphate, which is converted into lithium hydroxide. The chemical plant combines chemical reactors, precipitators, filtration and crystallisation. The demonstration plant is currently under construction and, when commissioned, is expected to operate for a year.