ROXAN, a world-first complex chemical processing robot, has been developed to perform on-site oxalate analysis for Alcoa’s local and international alumina refineries.

The robot was developed by Alcoa scientists in collaboration with its Technology Delivery Group (TDG), and ESSA, a local robotics company, to potentially save hundreds of hours of manual labour and reduce health and safety risks for workers.  TDG is Alcoa’s global refining research and development group and is based at Kwinana Refinery.

ROXAN's cutting-edge design will allow much safer and more efficient oxalate analysis for Alcoa / Image: Courtesy Alcoa

“Oxalate is an impurity in Bayer liquor and it accumulates over time," TDG project officer Kim-Louise Burke says.

"It comes into the process with bauxite and it is also produced when larger soil organic molecules degrade during the elevated temperature and pressure which occur in the first stage of our alumina manufacturing process.

"If the oxalate is not removed from the process it has an adverse impact on alumina quality and our refineries’ productivity.”

The ROXAN system, an acronym for Robotic Oxalate Analysis, was developed to fill the need for increasing efficiency of analysis procedures at Alcoa’s alumina refineries  and to reduce the potential for injury which can occur as a result of handling the chemicals and organic acids required for analysis.

“Oxalate is an organic molecule (di-carboxylic acid) commonly found in soil," Ms Burke says.

"The analysis of oxalate in Bayer liquors requires a complex proprietary procedure which includes treatment of the solution with strong acids, solvent extraction into an organic phase followed by separation and quantitative analysis on a gas chromatograph.

“ROXAN is a sophisticated 6-axis robotic chemical preparation system that is used to prepare Bayer process solutions for analysis of sodium oxalate. It automatically carries out a series of very precise chemical processes which prepare the samples for final analysis on our gas chromatography systems.

“It has the capacity to prepare up to 500 samples per day - 200 samples in an 8 hour period after calibration and setup then up to 300 samples overnight. The system can be monitored remotely. Once prepared, the samples are then transferred to a gas chromatograph for analysis.”

According to TDG program manager Dr Mike Nunes, ROXAN's features include safety systems, ensuring there is no possibility of negative human machine interface or chemical contact, and a speed of sample preparation more than double that of human ability.

The precision of ROXAN's analysis is beyond that of the best human operators, which frees up time to enable scientists to work on other areas of research and development.

“We have over 40 years experience in developing technology and delivering it to our refineries,” Dr Nunes says.

"This would be our fifth successful robot system that we’ve built. TDG created a robotic bauxite analysis system about 20 years ago now and we’re probably the world leaders in automated bauxite analysis. We drew on our previous experiences to go down this path with ROXAN."

Further Information: Kim-Louise Burke This e-mail address is being protected from spambots. You need JavaScript enabled to view it  and Dr Mike Nunes This e-mail address is being protected from spambots. You need JavaScript enabled to view it

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