Thulium
Thulium atomic absorption standard solution
CAS: 7440-30-4
Molecular Formula: Tm
Thulium - Names and Identifiers
Thulium - Physico-chemical Properties
| Molecular Formula | Tm |
| Molar Mass | 168.93 |
| Density | 9.332 g/mL at 25 °C (lit.) |
| Melting Point | 1545 °C (lit.) |
| Boling Point | 1950 °C (lit.) |
| Water Solubility | slowly reacts with H2O; soluble in dilute acids [HAW93] |
| Appearance | powder |
| Specific Gravity | 9.332 |
| Color | Silver-gray |
| Exposure Limit | ACGIH: TWA 2 ppm; STEL 4 ppmOSHA: TWA 2 ppm(5 mg/m3)NIOSH: IDLH 25 ppm; TWA 2 ppm(5 mg/m3); STEL 4 ppm(10 mg/m3) |
| Merck | 13,9471 |
| Sensitive | Air & Moisture Sensitive |
Thulium - Risk and Safety
| Risk Codes | R15 - Contact with water liberates extremely flammable gases R17 - Spontaneously flammable in air R36/37 - Irritating to eyes and respiratory system. R34 - Causes burns R23/24/25 - Toxic by inhalation, in contact with skin and if swallowed. |
| Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 - Wear suitable protective clothing. S43 - In case of fire use ... (there follows the type of fire-fighting equipment to be used.) S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S27 - Take off immediately all contaminated clothing. |
| UN IDs | UN 3089 4.1/PG 2 |
| WGK Germany | 3 |
| FLUKA BRAND F CODES | 10 |
| TSCA | Yes |
| HS Code | 28053090 |
| Hazard Class | 4.1 |
| Packing Group | II |
Thulium - Reference Information
| resistivity (resistivity) | 90 μΩ-cm, 20°C |
| EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
| Introduction | Thulium is a chemical element, symbol Tm, atomic number 69, and is a metal. Thulium is the second rarest lanthanide element (second only to promethium, which only exists in trace amounts on the earth). It is a soft, easy-to-process metal with a bright silver-gray luster, which slowly oxidizes in the air And lose luster. Thulium is expensive and quite rare, and is usually used as a radiation source in portable perspective devices and solid-state lasers. |
| Discovery history | In 1879, Swedish scientist Clive separated two new elements, thulium and holmium, from erbium soil. The content of thulium in the earth's crust is two hundred thousand. It is the least abundant element in rare earth elements. It mainly exists in yttrium phosphate and black rare gold ore. The natural stable isotope is only thulium 169. |
| Source | Thulium never exists in simple substance form in nature. It exists in a small amount in minerals of other rare earth elements, and often coexists with yttrium and gadolinium. In addition, thulium also exists in monazite, xenolith and black rare gold ore. Its mass abundance in the earth's crust is 0.5 mg/kg, and its molar abundance is 0.0005 ‰ (depending on the region, the value varies from 0.0004 ‰ to 0.0008 ‰), and it is 0.00025 ‰ in seawater ‰. In the solar system, the mass abundance is 0.0000002 ‰, and the molar abundance is 0.000000001 ‰. Thulium has the largest reserves in China, and also has abundant reserves in Australia, Brazil, Greenland, India, Tanzania and the United States. Thulium is the least abundant rare earth element on earth except promethium. |
| application | thulium is widely used in high-intensity power generation light sources, lasers, high-temperature superconductors and other fields. |
| Preparation | Thulium is mainly produced from monazite ore (containing 0.007% thulium) in river sand through ion exchange. The new ion exchange and solvent extraction make the separation of rare earth elements easier, which greatly reduces the cost of refining thulium. Nowadays, thulium mainly comes from the production of ion exchange resin in southern China. Among the rare earth elements produced here, 2/3 is yttrium, and thulium accounts for about 0.5% (very rare, equivalent to lutetium). Thulium metal can be obtained by reducing thulium oxide in a closed container with lanthanum or calcium. |
| Impact on the human body | Thulium is known to have no biological effect. Although a small amount of thulium can stimulate metabolism, soluble thulium salt has slight toxicity, but insoluble Thulium salt is non-toxic. Injection of thulium salt solution will cause degeneration of liver and spleen and fluctuation of hemoglobin content. Liver damage caused by thulium is more common in male rats than in female rats; nevertheless, thulium is still classified as low toxic. In the human body, the organs with the highest thulium content are the liver, kidneys and bones. Each person usually ingests a few micrograms of thulium per year. The roots of plants will not absorb thulium. Thulium accounts for about one billionth of the dry weight of vegetables. Thulium dust has inhalation and digestion toxicity, which may cause explosion in the air. Radioactive thulium can cause radiation disease. |
Last Update：2024-04-09 15:16:44
