Pgm refining is a highly complex process which requires a deep understanding of material science, pyrometalurgy, multi stage chemical separations and analytical science.
JM pgm refining process involves four key steps:
Evaluation is a critical stage in our pgm refining process. During this step we determine the pgm content of the customer’s material to enable us to agree with them what quantity or value of pgm we will return to them and the lead time for refining. Material tracking is crucial, and on receipt all customer batches are uniquely barcoded to ensure full traceability during evaluation.
Once terms are agreed feeds are no longer handled on a customer by customer basis, but are combined together in much larger batches for smelting. In this pyrometallurical process material is melted at temperatures over 1200°C for around 12 hours in large revertory furnaces to separate the non-metallic components. Two types of bullion feed are produced: a silver based feed containing primarily platinum and palladium, and an iron based feed which contains all five of the pgms.
The two bullion feeds then move to our chemical leaching plant, where they undergo multiple leaching to further concentrate the pgms. The silver based bullion is suspended in concentrated acid to slowly leach the silver, platinum and palladium into solution and separate out any gold. Gold impurities are sent for further refining. Silver is removed and further treated by us into saleable products, some of which are used in other businesses in the group.
Chemical separation is a highly complex multistage process in which we separate out the five pgms into their final product forms, commonly a pgm sponge, although other forms are produced depending on customer requirements. Our chemical separation process involves dissolution and a series of solvent extractions, evaporation, precipitation and filtration steps to produce highly pure salts for each individual pgm. These salts then undergo heat treatment to convert them to the final pure platinum group metal which is weighed and packed, ready for dispatch to our customers.