Johnson Matthey Metals Purification Processes

Johnson Matthey, Inc. is a global specialty chemicals company with a focus on precious metals, catalysts and fine chemicals. A precious metals "refinery" is operated at West Deptford, NJ, which is less than 10 minutes from our campus. This close proximity facilitates numerous interactions and projects that we have with Johnson Matthey. Johnson Matthey has provided significant support to our chemical engineering department and was a "charter member" of the PRIDE program, Partners with Rowan in Developing Engineers. They have continuously employed Rowan chemical engineering students as interns, weekend shift workers, and permanent employees. Johnson Matthey was a pioneer of the Engineering Clinic Program, sponsoring two projects in the first year of the program and 1-2 projects for the five years that have since passed. These projects have focused on precious metals separation and recovery. The objective of all these projects has been to investigate novel techniques that have the potential to replace current "traditional" refinery process units.

At the refinery, precious metals such as Pt, Pd, Rh, are purified from feed streams containing many unwanted metal species and other impurities. The feed streams are made up of spent catalysts from which precious metals are recovered and recycled to feed stream from mines. In the refinery, there are many dissolution, selective-precipitation, and filtration steps. Using innovative processes, like membranes, the plant capacity, product purity, and processing cost have the potential to be improved. In essence, students have an opportunity in the engineering clinic to conduct engineering projects that are equivalent in scope to those done by engineers in the plant.

One of the Johnson Matthey projects the development of a membrane process to use electrodialysis for separation of a precious metal chloride ion solution, in an intermediate process step, that is contaminated with unwanted acids and salts. Technical aspects of the project focused on process design, performance evaluation, economic evaluation, and scale-up. Other technologies investigated through different projects include liquid-liquid extraction, ceramic membrane microfiltration, ion exchange, and adsorption.

These projects have been beneficial to Johnson Matthey, students, and faculty. Based on the results of these projects, JMI has added several new process units to their refinery processes that result in increased capacity, higher product purity, and shorter "hold-up" time for precious metals. Students have learned new technology through industrial projects, have gained exposure to industrial culture, and in many cases have secured summer or full-time employment with Johnson Matthey. Faculty have developed valuable relationships with industrial partners, secured funding for research projects, and learned about new technologies.