Mining & fabrication

Primary production of PGMs represents the transfer of metal from below ground resource to above ground material stock and should be regarded as an investment because the metal is usually available to be recovered for reuse in subsequent product life cycles with no deterioration in quality.

According to the U.S. Geological Survey, 95% of the known world
reserves of PGMs are located in South Africa. 58% of world primary PGM production takes place in South Africa and Russia accounts for a further 26%, most of this as a co-product of nickel mining. Nearly all of the rest comes from Zimbabwe, Canada, and the United States.
Deposits in Russia and North America have high palladium contents while deposits in South Africa and Zimbabwe are richer in platinum.

The extraction of natural resources and the manufacture of PGM products create large revenues and thereby contribute greatly to the economic growth and wealth of the countries where the metals are mined and processed.

Extraction & Refining

Extraction, concentration and refining of PGMs require complex, costly and energy-intensive processes that may take up to six months to produce the final metal from the first time PGM-bearing ore is broken in a mine.
Most PGM production takes place at undeground operations. These are costly and labour-intensive. In addition, high investment costs limit the scope for mechanisation and modernisation of machinery, equipment and other capital goods.

In South Africa, PGM-bearing ores generally have a low PGM content of between 2 and 6 grams per tonne and it will typically take up to six months and between 10 and 40 tonnes of ore to produce one troy ounce of platinum (31,1035g).

PGM ore is mined underground and less usually in open-cast pits. It is blasted out of the ground; on surface, the ore is crushed and milled into fine particles. Wet chemical treatment known as froth flotation produces a concentrate which is dried and smelted in an electric furnace at temperatures over 1,500°C. A matte containing the valuable metals is transferred to converters to remove iron and sulphur. PGMs are then separated from the base metals nickel, copper and cobalt, refined to a high level of purity using a combination of solvent extraction, distillation and ion-exchange techniques.

The secondary production of PGMs includes the recycling of these metals from industrial applications and end-of-life products, as well as the recovery of metals from by-products and residues created in primary production. Secondary production plays an important role in lowering the environmental footprint of global PGM production and contributes a significant part of the PGM supply.

Secondary production in the PGM life cycle

Recycling is achieved through a complex, global web of companies, processes and material flows arranged to maximize the efficiency of PGM recovery from a variety of sources.

Typically, PGM-containing materials from industrial applications and by-products and residues are received directly by secondary producers, while consumer products must be first collected from consumers and pre-processed to separate the PGM-containing components from other materials (e.g. removal of autocatalyst from a vehicle).

Smelting or Dissolving
Secondary production is composed of two processes. First, PGM-containing materials are either smelted to form a molten metal matte, or dissolved to bring the PGMs into a solution. Second, the PGM-enriched output from step one is then refined to recover the individual metals separately in a pure form identical to that from primary production.

Recycling Efficiencies
Using state-of-the art recycling technologies, over 95% of the PGM content of spent automotive catalysts (and other PGM-containing materials) can be repeatedly recovered.

PGM materials that are collected at a very high rate or enter secondary production directly from industrial processes, such as industrial catalysts, are recycled at a rate near the 95% maximum potential (this is called close-loop recycling). For PGMs in consumer products, however, end-of-life recycling rates are lower, as high recovery requires an efficient recycling chain from collection to refining (open-loop recycling).

Unfortunately, a well-functioning chain that targets PGM recovery is not
always in place when these products reach their ultimate end-of-life and
are ready for recycling. Thus, the end-of-life recycling rate for these
PGMs is largely determined by the weakest link in the chain for the specific product.

Targeting the weakest link in the chain provides the best opportunity for improving the recycling rate of PGMs, which in turn can help reduce the overall environmental impact of the PGM supply and contributes to a life cycle thinking.

Where are PGMs recylced?
Depending on the application, most PGMs are recoverable through the product lifecycle, from production scrap through to end-of-life materials.

PGMs are reused in two ways:

1. Open loop recycling: when the original purchaser of the metal does not retain control over the PGM, the metal is available to the market again once recovered. The main source of open-loop metal is automotive catalytic converters, which are widely recovered from scrapped vehicles and recycled to recover the contained platinum, palladium or rhodium contained. Some metal is also recovered from the jewellery and electronics markets.
2. Closed loop recycling: refers to the situation where the metal remains within the application, e.g., when metal is recovered from used chemical catalysts and is used to produce fresh catalysts to replace the spent charge. While this metal is processed by PGM refiners, the equivalent amount of metal is usually returned to the original owner, who retains the metal value. As the net amount of metal in use has not changed, this returned metal is not counted towards market supply. Re-using metal in such way avoids the need for virgin mined metal, thereby contributing to make demand more sustainable.

Who recycles PGMs?

Important recylcers by volume of PGMs include the following companies:

• Heraeus
• Johnson Matthey
• Furuya Metals
• Umicore
• BASF

With the exemption of Furuya Metals, all companies named above are members of the IPA.

Why are PGMs recycled?

The high value of PGMs leads to them being widely recycled. It also drives the recycling of other metals present in PGM-containing products that might not otherwise be recovered.

Secondary production or recycling plays an important role in lowering the environmental footprint of the global PGM production. With responsible stewardship, PGMs can be recycled over and over again with a minimum to zero loss, resulting in a continual reduction of the environmental load of each successive life cycle. However, without virgin mined platinum group metals, global supply would not meet demand for the multiple industries using PGMs such as automotive, medicine, chemical, and petroleum that reduce emissions or improve life and health. Hence, primary and secondary production are intertwined.

Among secondary resources (recycling), spent automotive catalysts (SACs) play a crucial role because they can deliver more than 40% of European PGM demand. It is estimated that between one third to one quarter of total PGM demand globally can currently be met by recycling. Note that this is only considering net demand, i.e. for ‘new’ metal to be sourced from the market. A large amount of PGM is routinely recycled in ‘closed loop’ within applications, meaning that a much higher proportion of gross demand is met by recycling.

The technical recyclability of PGMs is very high, so refining recovery can approach 100% in an efficient, optimised and targeted process. Where recycling rates are low this is usually because of material losses in collection, or because metal is lost in use, so it is not recoverable. Collection losses for PGM can be high, and are estimated to be as much as 30% for PGM on SACs (global average – this will be higher in regions with mature recycling networks such as Europe).

The PGM industry itself repeatedly recycles PGMs from their applications with recovery efficiencies of up to 95%. It collaborates with other stakeholders to increase recycling rates. Targeting the weakest link in the recycling chain provides the best opportunity for improving the recycling rate of PGMs, which in turn can help reduce the overall environmental impact of the PGM supply.

How can recycling rates be improved?

The main driver for recycling, besides of the value of the metal, is the lower environmental footprint of a recycled ounce in comparison to a virgin (mined) ounce. With autocatalysts still representing the major single demand application for platinum, palladium, and rhodium, a considerable amount of secondary material is currently “on the road” and is ready to be recycled (“urban mining”) after the vehicles reach the end of their lifetime, which is usually after 15-18 years. Recycling can hence be improved by ensuring that as many spent autocatalysts as possible are made available for professional recycling at the end of the vehicles’ lifetime.

Therefore, for regulators concerned with improving recycling recoveries for PGM, the focus should be on regulatory measures and incentives that improve the collection of PGM-containing equipment at end-of-life. In some applications, funding for R&D to reduce losses in use could also be helpful. Once material is collected, then it can enter the existing infrastructure that is in place for PGM recycling, and it can be refined in existing secondary facilities.