Inco, the international metals and mining company, is using a fibre optic spectrometer from Astranet Systems to control a Palladium refining process, which involves stripping out a Palladium complex from a solvent. To monitor this process using conventional spectrometry proved difficult due to the very high optical density of the Palladium complex (>2A at a 1mm path length at the start of the stripping process, falling to 0.3 to 0.4A as the Palladium is removed).
The fibre optic spectrometer is equipped with a specially produced PTFE coated Hellma 1mm path-length dip probe and monitors the process continuously, fully integrated with the company’s process control system. The instrument has no moving parts, making it extremely rugged and ideal for the plant environment, where it operates in close proximity to ammonia and hydrochloric acid solutions. Inco’s Richard Ellis said: “This system has enabled a transition from batch to continuous processing.
We were concerned about contamination, but Astranet developed a drift correction programme to monitor any probe contamination using a different wavelength from the analytical wavelength.
We only need to clean the probe every couple of weeks.” According to Mike Mills of Astranet Systems: ”We don’t just sell boxes. Astranet provides a unique UK-based service, using local programmers and engineers to create integrated process control solutions based on fibre optic spectrometers.”