Category: Insights

Catalytic reforming units in refineries use catalysts made of platinum, often combined with rhenium, on an alumina support. When the catalyst is replaced, the precious metal is still there. Spent reforming catalyst is therefore sent for recovery, and its value depends on how much metal a lot holds and how easily it can be processed.

What decides the value

• Platinum and rhenium content. This is measured by assay on representative samples and is the main driver of value.
• Weight of the lot. The metal content is applied to the dry weight, so the moisture in the material matters.
• Carbon and other residues. Coke, sulfur and hydrocarbons from service can add processing steps.
• Fines and foreign material. Broken catalyst, ceramic balls and other support material change the weight and the handling.

Why sampling matters

A drum of catalyst can vary from top to bottom, and a lot can vary from drum to drum. Value is agreed on samples that represent the whole lot, so the sampling method is usually agreed before any material moves. Keeping drums labelled and in the same order they came out of the unit helps.

Other catalysts with precious metals

Isomerization and dehydrogenation catalysts can also contain platinum or palladium. Chemical and pharmaceutical catalysts such as Pd/C and Pt/C are a separate group, with their own sampling and processing.

Preparing to sell spent catalyst

• Note the unit the catalyst came from and the original catalyst type, if known.
• Count the drums or bags and note the approximate weight.
• Keep any analysis reports from the refinery.
• Take photos of the drums, labels and a sample of the material.

Piston aircraft engines use two spark plugs per cylinder, and the plugs are replaced or overhauled on a regular schedule. Maintenance shops, flight schools and engine overhaul shops often build up boxes of used plugs. Their scrap value depends mostly on the type of electrode inside.

Two main types of aircraft spark plugs

• Massive electrode plugs use thick ground electrodes made of nickel alloy. They are common and robust, and their scrap value is lower.
• Fine-wire plugs use thin electrodes made of platinum or iridium. The precious metal is what makes them more valuable as scrap.

How to tell them apart

Look at the firing end. Massive electrode plugs show two or more wide, flat ground electrodes around the centre electrode. Fine-wire plugs show thin wire electrodes that look like small pins. The part number printed on the plug or on the box also identifies the type, and buyers can check it quickly from a photo.

Turbine igniter plugs and automotive plugs

Turbine engines use igniter plugs instead of spark plugs, and some designs contain precious metal in the electrode or tip. Automotive iridium and platinum spark plugs also contain small amounts of precious metal. They are best kept apart from aircraft plugs, because each group is valued differently.

How to prepare a lot of plugs

• Sort fine-wire plugs from massive electrode plugs.
• Keep igniter plugs and automotive plugs in separate bags or boxes.
• Count the plugs or weigh each group.
• Photograph the firing ends and the part numbers.

A sorted lot is quicker to assess and usually earns a better price than a mixed one, because the buyer does not need to allow for uncertainty.

Most first conversations about industrial scrap happen on WhatsApp or by email. Clear photos let a buyer identify the material, judge its condition and decide whether an on-site inspection or a sample is the next step. A few minutes spent on photos can save days of back and forth.

The five photos every buyer wants

• The whole lot. One wide shot that shows everything together, with the pallets, drums or bags it sits in.
• Close-ups of the material. Two or three sharp photos of the surface, coating, electrode tips or broken face, taken in good light.
• Labels and markings. Nameplates, part numbers, drum labels and stamped codes often identify the material faster than anything else.
• A size reference. Put a tape measure, a pen or a hand next to a piece so its size is clear.
• Anything mixed in. Copper bars, steel frames, plastic parts or different materials in the same lot.

Tips for clear photos

• Use daylight or bright, even light and avoid strong shadows.
• Hold the phone steady and tap the screen to focus on the material.
• Wipe off loose dust or salt from one area if the surface is covered.
• Send the original photos rather than screenshots, so the detail stays sharp.

Details to send with the photos

• What the material is, if you know, and the process or equipment it came from.
• An estimated weight or number of pieces.
• How it is packed and whether it is sorted.
• The country and city where it is stored.
• Any assay reports, data sheets or original specifications.

When photos are not enough

Some materials look the same but carry very different amounts of metal. Catalysts, concentrates, powders and some coated parts usually need a sample tested before a buyer can give a firm price. Photos still help here, because they show how the lot should be sampled.

Titanium anodes coated with mixed metal oxides, often called MMO or DSA anodes, are used in chlor-alkali and chlorate plants, electroplating, copper foil production, electrowinning, water treatment and cathodic protection. When an anode reaches the end of its service life it is usually replaced or sent for recoating. The spent anode still holds value in two places: the precious metal left in its coating and the titanium underneath.

What is inside a spent MMO anode

The base of the anode is a titanium substrate, usually commercially pure titanium in the form of expanded mesh, plate, tube, rod or wire. On top of it sits a thin oxide coating that does the electrochemical work.

• Ruthenium-based coatings are common where the anode produces chlorine, for example in chlor-alkali, chlorate and electrochlorination cells.
• Iridium-tantalum coatings are common where the anode produces oxygen, for example in copper foil, electrowinning and many plating lines.
• Platinum-plated anodes are a separate group with a different coating structure, and they are valued in a different way.

What changes the value of a lot

No two lots of spent anodes are the same. These are the points a buyer looks at first:

• Coating type. Iridium, ruthenium and platinum have very different market prices, so identifying the coating is the first step.
• Remaining coating. Coating wears away during service. An anode removed early holds more metal than one run until it failed.
• Attachments. Copper conductor bars, titanium-clad copper, bolts, plastic and rubber parts add weight that is not anode. Removing them, or telling the buyer about them, avoids surprises.
• Condition. Heavy scale, salt deposits and other contamination make sampling and processing harder.
• Quantity and sorting. A lot sorted by coating type and application is easier to assess than a mixed pile.

How the coating content is checked

A handheld XRF analyser can identify the coating elements on site and show whether pieces in a lot are similar. For a firm figure on precious metal content, representative samples are analysed in a laboratory. For mixed or unknown lots, it is common to agree on sampling before the material moves.

Preparing your anodes before asking for a price

• Take a photo of the whole lot and close-ups of the coated surface.
• Note the process the anodes came from, such as chlor-alkali, plating or copper foil.
• Keep any labels, drawings or original specifications.
• Estimate the total weight and the share of copper or other attachments.
• Keep different anode types apart where you can.

With this information a buyer can give a first assessment from photos and decide whether a sample or an on-site inspection is the next step.