In the chlor-alkali industry, traditional recycling methods for scrap platinized titanium anode (with a platinum coating thickness of 5–20 μm) can only recover 60–70% of the platinum. Reverse pulse electrolytic stripping technology has completely transformed the low recovery efficiency situation: by applying a 100 Hz pulse current (reverse duty cycle of 30%) in a NaNO₃ electrolyte, platinum stripping efficiency has surged to 98%. After sandblasting and acid etching (HF:HNO₃ = 1:3) to repair the titanium substrate, it can be re-plated, extending the lifespan of the platinized titanium anode by three times. After adopting this technology, a U.S. company reduced the cost of anode recovery per square meter from $170 to $55, achieving a titanium alloy recycling rate of 90%. This process combines precious metal regeneration with substrate reuse, directly reducing raw material costs by over 30%.
Industrial-grade platinized titanium anode are categorized into two types based on coating processes: electroplated platinum layers (thickness 0.5–5 μm) with resistivity below 0.1 Ω•cm², suitable for high-precision electroplating applications such as gold plating of electronic components; platinum coating sintering processes are lower in cost but have higher resistivity, primarily used in conventional applications like wastewater treatment. Structurally, platinized titanium anode can be customized into mesh, plate, rod, or tube shapes. Mesh designs (pore size 0.5–3 mm) enhance the diffusion efficiency of high-viscosity molten salt electrolytes by 20%, while tube-shaped platinized titanium anode are more suitable for closed electrochemical reactors. In addition to pure platinum, IrO₂-Ta₂O₅ composite coatings can further extend service life in acidic environments.
The global platinum coated titanium anode market is driven by both technological performance and environmental regulations. In North America and Europe, driven by the upgrading needs of the chlor-alkali industry, the annual growth rate of platinum-based metal oxide-coated titanium anodes reaches 8.5%. Japanese companies prioritize the use of 0.5-1mm thick mesh-type platinized titanium anode in water treatment applications, as their oxygen evolution overpotential (1.385V) is 10% lower than that of ruthenium-iridium coatings, significantly reducing electrolysis energy consumption. Leading brands such as Germany's METAKEM and the US's Jennings Anodes focus on high-temperature applications, introducing gradient platinum-iridium composite-coated platinized titanium anodes capable of withstanding 600°C molten salt electrolysis; Chinese suppliers, meanwhile, are entering niche markets with customized mesh structures, accounting for 40% of total production capacity in the Asia-Pacific region. The future growth of the platinum coated titanium anode market will depend on increased penetration in the new energy sector, particularly the demand for titanium-based electrode plates in solid-state batteries.
After disposal, recycled platinized titanium anodes exhibit a grayish-black, loose, porous structure with platinum content ≥99.95%. Recycling 1 kilogram of sponge platinum reduces the extraction of 10 tons of primary platinum ore and lowers energy consumption by 80%. Industrial data from German company Umicore shows that in the recycling of automotive exhaust catalysts, each ton of waste material can yield 1.2–1.5 kilograms of platinum, but this requires high-temperature chlorination and volatilization (1,000°C with 30% chlorine gas) to convert and dissolve the platinum. However, sponge platinum recovered from platinized titanium anodes, due to its porous nature, has an electrochemical active surface area (60–120 m²/g) far exceeding that of platinum black catalysts, resulting in a 15–20% increase in value during fuel cell electrode regeneration. Life cycle assessment confirms that the carbon emissions (3,200 kg CO₂) from recovering one kilogram of platinum using the ion exchange method are only 55% of those from the traditional aqua regia method, and the amount of secondary waste is reduced by 76%, making it the optimal solution for large-scale processing. The recovery of platinum from platinized titanium anodes has transitioned from a cost item to a core value-creating process.
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