Global mining company seeks solutions for protective anode coating for aluminum smelting

Rio Tinto is seeking a solution to apply a proprietary protective coating onto baked carbon anodes that are used during the production of aluminium. Large-scale trials using coated anodes have been successfully completed at Bell Bay Aluminium, with the possibility for full implementation on site now being studied. In the large-scale trials, the coating was applied to anodes manually. For full-scale implementation across the site, a low-cost automated process will be required.

The initial target site is Bell Bay Aluminium. Any solution that is developed could be relevant to our other aluminium smelters. The solution should be safe and cost effective. 

We are looking for partners in technology solutions. Depending upon the feasibility, cost and risk, we have financing available. We can also provide access to our technical specialists and provide more information for potential plant trials. 

Some technical information:

• Coating is to be applied onto baked anodes before they are delivered to the reduction cell 
• Approximately 680 anodes per day will require coating 
• Approximately 14 kilograms of coating is required for each anode* 
• Total surface area of each anode to be coated is approximately 2m2* 
• Each anode weighs approximately 550 kilograms 
• Coating would ideally be applied as a single coat onto four sides and top of each anode (coating the bottom is not required)
• Multiple coats may be acceptable within constraints of the production cycle 

• Coating cannot be applied inside the two connection holes on the top side of the anode or onto the electrical connections that sit inside the connection holes. 

• The coating is relatively inert and applied as a slurry, with a viscosity similar to cement render 
• The content of the coating slurry needs to be kept in suspension during application 
• Requirements for drying the coated anodes will depend on where in the anode production process the coating is applied (an additional drying process may or may not be required; however, the coated anode must be dry when it is delivered to the reduction cell). 

In your application, we encourage you to include: 

• Evidence that can help and provide confidence in the feasibility and effectiveness of your solution, or concept for either or both of the following:
• methodology/process for coating the anodes 
• a solution for incorporating the coating process into the anode production process. 
• A recommended course of action. 

Rio Tinto is a mining and metals company operating in around 36 countries around the world. Our purpose is to produce the materials essential to human progress.

Our four product groups bring this purpose to life: Aluminium, Copper & Diamonds, Energy & Minerals and Iron Ore. These are complemented by our Growth & Innovation and Commercial groups, as well as our service and support functions.

The Bell Bay aluminium smelter is part of the Aluminium product group and located in Tasmania.

Further information is available on the Rio Tinto website https://www.riotinto.com