Thermocouple waste indeed contains platinum group metals, especially platinum and rhodium, two high-value elements. This article explores the classification of thermocouples and the industries where thermocouple waste can be found.
What Types of Precious Metal Thermocouples Are There?
Precious metal thermocouples mainly include the following specific models:
S-type (Platinum-Rhodium 10)
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Composition: The positive electrode is a platinum-rhodium 10 alloy (containing 10% rhodium and 90% platinum), and the negative electrode is pure platinum.
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Applications: Long-term use temperature up to 1300℃, short-term up to 1600℃, suitable for oxidizing and inert environments.
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Features: High accuracy, stable physical and chemical properties, and high temperature measurement limit.
R-type (Platinum-Rhodium 13)
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Composition: The positive electrode is a platinum-rhodium 13 alloy (containing 13% rhodium and 87% platinum), and the negative electrode is pure platinum.
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Applications: Long-term use temperature up to 1300℃, short-term up to 1600℃, characterized by high accuracy, strong stability, and excellent oxidation resistance.
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Features: Better stability than S-type.
B-type (Platinum-Rhodium 30-Platinum-Rhodium 6)
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Composition: The positive electrode is a platinum-rhodium 30 alloy (containing 30% rhodium and 70% platinum), and the negative electrode is a platinum-rhodium 6 alloy (containing 6% rhodium and 94% platinum).
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Applications: Long-term use temperature up to 1600℃, short-term up to 1800℃, suitable for higher temperature environments.
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Features: The temperature measurement limit can reach 1800℃ in the short term, with high measurement accuracy.
Which industries can thermocouple waste be found?
Thermocouple recycling is mainly concentrated in these industries and equipment, whose waste often contains high-value platinum group metals:
I. Core Recycling Industries
Metallurgy and Chemical Industry
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Equipment: High-temperature furnaces, reactors, refining equipment
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Reason: Platinum-rhodium thermocouples are in long-term contact with high-temperature corrosive environments, and the platinum-rhodium content remains above 80% after being scrapped. Aerospace
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Equipment: Rocket engine test stands, spacecraft thermal control systems
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Features: Type B thermocouples (Platinum-Rhodium 30 – Platinum-Rhodium 6) withstand high temperatures up to 1800℃ and have extremely high recycling value.
Energy and Power
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Equipment: Thermal power plant boilers, nuclear power plant heat exchangers
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Data: Over 200 thermocouples are replaced annually in a single generator unit.
II. Other High-Value Fields
Pharmaceuticals and Food: Sterilization equipment, fermentation tanks (Type S thermocouples (Platinum-Rhodium 10 – Platinum)
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Glass and Ceramics: Kiln temperature measurement (Type R thermocouples (Platinum-Rhodium 13 – Platinum))
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Laboratories: High-precision thermocouples for scientific research (such as Type S and Type R)
What are the differences between Type S, Type R, and Type B platinum-rhodium thermocouple wires?
| characteristic | S-type | R-type | B-type |
| Positive electrode components | Platinum-rhodium alloy (Rh 10%) | Platinum-rhodium alloy (Rh 13%) | Platinum-rhodium alloy (Rh 30%) |
| Negative electrode components | Pure platinum | Pure platinum | Platinum-rhodium alloy (Rh 6%) |
| Long-term maximum temperature | 1300°C | 1300°C | 1600°C |
| Short-term highest temperature | 1600°C | 1600°C | 1800°C |
| Main features |
Good stability, high temperature measurement |
The thermoelectric power is approximately 15% |
No compensation wires are needed, and the |
| Typical applications |
High-precision laboratory, standard temperature |
Higher sensitivity is required for high-temperature measurements. |
Ultra-high temperature measurement above |
Huatuo – Your Reliable Global Buyer of Thermocouple Scrap Metals
Huatuo Company specializes in the professional recycling of thermocouple scrap through its professional business scope, mature precious metal recycling technology, and strict environmental compliance. We are your reliable recycling partner.
If you have thermocouple scrap but are unsure of its recycling value, please contact our experts immediately. We provide free, professional sample testing and analysis, and we can also cover the shipping costs of the samples, saving you time and effort and maximizing the value of your scrap.
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Email: info@huatuometals.com