Hafnium is a shiny silver-gray tetravalent transition metal
Views : 411
Author : TRUNNANO
Update time : 2021-03-05 09:23:46
Overview of hafnium Hafnium is a chemical element whose symbol is Hf and its atomic number is 72. Hafnium is a shiny silver-gray tetravalent transition metal with similar chemical properties to zirconium, and it exists in many zirconium minerals. Dmitri Mendeleev predicted its existence in 1869, but it was not until 1923 that Coster and Hevesy discovered it, making it the last stable element to be discovered.
There are 6 natural stable isotopes of hafnium: hafnium 174, 176, 177, 178, 179 and 180. Hafnium does not interact with dilute hydrochloric acid, dilute sulfuric acid and strong alkaline solutions, but is soluble in hydrofluoric acid and aqua regia. The name of this element comes from the Latin name of Copenhagen. The content of hafnium in the earth's crust is 0.00045%, and it is often associated with zirconium in nature. Hafnium is used in filaments and electrodes. Some semiconductor manufacturing processes use integrated circuits whose oxides have characteristic lengths of 45 nanometers and smaller. Some special-purpose superalloys contain hafnium, niobium, titanium or tungsten.
The large neutron capture cross-section of hafnium makes it a good material for neutron absorption in the control rods of nuclear power plants, but at the same time, it is required to be removed from the transparent corrosion-resistant zirconium alloy used in nuclear reactors.
What are the Characteristics of hafnium? Hafnium is a shiny silver malleable metal, corrosion-resistant, and chemical properties similar to zirconium (because it has the same number of valence electrons and belongs to the same group, but it also has a relativistic effect; the expected atomic radius is from the fifth to the first The expansion of phase 6 was almost completely offset by the contraction of lanthanides). Hafnium changes form from alpha, the hexagonal crowded lattice, its beta form, body-centered cubic lattice, the physical properties of the 2388 k hafnium metal sample significantly affect zirconium impurities, especially the nuclear properties, these two elements are the most difficult to separate, Because of their chemical similarity.
The chemical properties of hafnium and zirconium are very similar, and they cannot be separated because of different chemical reactions. The melting point and boiling point of the compound and the solubility in the solvent are the main differences in the chemical properties of these two twin elements.
Hafnium is estimated to account for 5.8 ppm of the mass of the earth’s crust. It does not exist as a free element on the earth but is solid-dissolved with zirconium in natural zirconium compounds, such as zircon, ZrSiO4, and usually, about 1-4% of zirconium is replaced by Hf.
The main sources of zircon (and hafnium) ore are heavy mineral sand deposits, pegmatites, especially in Brazil and Malawi, and carbonate intrusions, especially the coronal polymetallic deposits in Mount Wilde, Western Australia. One potential source of hafnium is the rough tuff containing rare zircon-hafnium silicate, aluminum translucent or Armstrong ore in the Dubbo area of New South Wales, Australia.
One source estimates that if the world population increases and demand increases, hafnium reserves can be maintained for less than 10 years. In reality, due to the coexistence of hafnium and zirconium, hafnium can always be used as a by-product of zirconium extraction under low-demand conditions.
Is hafnium a rare earth metal? Hafnium is rarely free but exists in most zirconium minerals at a concentration of up to 5%. Hafnium is the 45th most abundant element on the earth. According to the study of Chemical Kuhl, it occupies about 3.3 parts per million of the earth's crust.
Is hafnium poisonous? Hafnium metal is not toxic. This metal is completely insoluble in water, salt solutions or human chemicals. Exposure to hafnium can occur through inhalation, ingestion, and eye or skin contact. Excessive exposure to hafnium and its compounds may cause slight irritation of the eyes, skin and mucous membranes.
How is hafnium used in daily life? Hafnium is a good neutron absorber used in the control rods of nuclear reactors. Hafnium is also used as a getter in the vacuum tube. This material combines and removes traces of gas in the vacuum tube. Hafnium is used as an alloying agent for iron, titanium, niobium and other metals. Hafnium is a shiny silver metal that is corrosion-resistant and can be drawn into threads. Hafnium is a good neutron absorber used to make control rods, such as those on nuclear submarines. It also has a high melting point, so it is used in plasma torches.
The new method solves the old mystery: hafnium isotopes determine the origin of high-quality Roman glass Glass is a very interesting archaeological material: although its fragility and beauty are attractive in themselves, geochemical studies of invisible tracers can reveal more than what is seen on the surface.The glass industry in Rome is very prolific, producing drinking and catering products, window glass and stained glass "stones" for wall mosaics. One of its outstanding achievements is the production of a large number of colorless and transparent glass, which is especially suitable for making high-quality cut drinkers. However, it is known that a large amount of Roman glass was made in Palestine, where archaeologists discovered a furnace used to produce colorless glass. No such furnace has been found in Egypt. So far, it is very challenging to distinguish the glass made in these two regions from a scientific point of view.
Now, an international collaboration led by UrbNet's assistant professor Gry Barfod and AGiR from Aarhus University has found a solution. Their research on Roman glass in the Denmark-Germany Jerash Northwest Project in Jordan showed that the isotope of the rare element hafnium can be used to distinguish Egyptian and Palestinian glass, and provided convincing evidence of the famous colorless glass "Alexander "It is indeed made in Egypt.
"The hafnium isotopes are geologically proven to be important tracers of the origin of sedimentary sediments, so I hope this isotope system can leave fingerprints on the sand used in glass manufacturing," said Gry Barfod. Charles Lescher, a professor at Aarhus University who is a co-author of the publication, went on to say: "This expectation is confirmed by the measurement results, which proves the close connection between archaeology and geology."
Hafnium isotopes have never been used by archaeologists to investigate the trade of ancient man-made materials such as ceramics and glass. Co-author, Professor Ian of University College London, commented: "These exciting results clearly show the potential of hafnium isotopes in explaining the origin of early materials. I predict that they will become important scientific tools for our study of ancient economies. component."
The sand on the Mediterranean coast of Egypt and the Levant (Palestine, Israel, Lebanon, and Syria) originates from the Nile River and is an ideal place for glass production because the sand contains a large amount of lime, which can keep the glass stable and non-degradable. In the Levant, they made clear glass by adding manganese-which is good, but not perfect. The second type of Roman glass that scientists are now showing comes from Egypt. Glassmakers made the glass transparent by adding antimony (Sb); therefore, this is the most precious glass.
TRUNNANO (aka. Luoyang Tongrun Nano Technology Co. Ltd.) is a trusted global chemical material supplier & manufacturer with over 12 years' experience in providing super high-quality chemicals and Nanomaterials. Currently, our company has successfully developed a series of materials. TheHafnium powder produced by our company has high purity, fine particle size and impurity content. Send us an email or click on the needed products to send an inquiry.
