6 things you need to know about zirconium

Zirconium is a metal element with the element symbol Zr. It is located in Group IV-B in the periodic table of elements. Its atomic number is 40, its density is 6.49g/cm³, its melting point is 1852°C, and its boiling point is 4377°C. Zirconium is a silver-white transition metal that is often called a "rare metal" because of its complex production process and difficulty in extraction. In fact, the content of zirconium in the earth's crust is about 0.025%, ranking 19th, almost equal to chromium, and more than common metals copper, lead, nickel, and zinc, but its distribution is very scattered. Zirconium easily forms an oxide film on its surface in the air, which is shiny and similar in appearance to steel. Zirconium has corrosion resistance, but is soluble in hydrofluoric acid and aqua regia; at high temperatures, it can react with many elements to form solid solution compounds. The corrosion resistance of zirconium is better than that of titanium, and is close to tantalum and niobium. In view of the good plasticity of zirconium, it is often processed into plates, wires, etc. Zirconium can absorb a large amount of oxygen, hydrogen, nitrogen and other gases when heated, and can be used as a hydrogen storage material. As a relatively scarce resource, zirconium is widely used in electronics, ceramics, glass, petrochemicals, building materials, medicine, textiles and daily necessities. Australia and South Africa are where zirconium resources are concentrated, while China and Europe are the main consumer regions of zirconium.

Zirconium is named after zircon, which has been used as jewelry by humans for centuries. Zircon is also mentioned in the Bible as one of the 12 gemstones worn by the high priests of Israel.

Zircon comes in a variety of beautiful colors from orange to red, and colorless zircon will show a dazzling brilliance after being cut. It is for this reason that zircon was mistaken for a soft diamond for a long time.

The discovery and extraction of zirconium is mainly attributed to two chemists, German chemist Martin Heinrich Klaproth and Swedish chemist Jöns Jacob Berzelius ), these two chemists made extraordinary contributions to the discovery and purification of zirconium.

In 1789, the German chemist Martin proved that zircon was not a diamond, clarifying people's misunderstandings about zircon. By heating zircon with the reactive compound sodium hydroxide, he discovered that the two substances reacted to form an oxide. Martin believed that this oxide contained a new element. He named the new oxide zirconium oxide and the new element zirconium.

Martin was unable to extract pure zirconium because it was chemically similar to hafnium, which often co-occurs with zirconium in zirconium ores. It was not until 35 years later, in 1824, that Swedish chemist Bechlias produced pure zirconium for the first time. At that time, several other chemists were also working on this work, but none succeeded. Bacilias succeeded in extracting pure zirconium by heating a mixture of potassium and potassium fluozirconate in an iron tube. The purity of the black powdered zirconium obtained in the experiment reached 93%. The purity of the zirconium produced by Bechilias' purification could not be improved. It was not until nearly 100 years later that high-purity zirconium was produced. Today, most zirconium is extracted from zircon (ZrSiO4) and zirconium dioxide (ZrO2). The extraction process is called the "Kroll Process".

The name zirconium comes from zircon, which comes from the Persian word for "gold" (zargun). It is said that this name is due to the eye-catching color of some zircon jewelry. In fact, there are many colors of zircon. Red, brown, green and yellow are more common. Colorless zircon is also more common among humans.

Since ancient times, zirconium has been used as a gemstone because of its rich and colorful colors, playing a decorative role in human life. As people's understanding of zirconium continues to deepen, its applications are becoming more and more widespread. Perhaps most people are unfamiliar with zirconium, but it has penetrated into every aspect of our lives. For example, zirconium is indispensable in various surrounding buildings, ceramics, knives, decorations, etc. that are essential in life, and even in the military and nuclear power fields.

Zirconium products are rich in variety and in various forms. The initial mineral form is zircon sand. After treatment with caustic soda, water washing, etc., primary products such as zirconium silicate and zirconium oxychloride can be produced. With continued calcination, chlorination, and reduction, secondary products can also be produced. Zirconia, industrial grade zirconium sponge and other products; if the purification and separation technology reaches a certain level, nuclear energy grade zirconium sponge can be made.

Zirconium has a wide range of applications. It is mainly used in ceramics, refractory materials and other fields in the form of zirconium silicate and zirconium oxide. Only 3%-4% of zirconium ores are processed into metallic zirconium (or zirconium sponge), and then further processed into various zirconium materials. Because metallic zirconium has a small thermal neutron absorption cross-section, metallic zirconium has excellent nuclear properties. Nuclear-grade zirconium uses this characteristic to be used as structural materials and uranium fuel elements for nuclear-powered aircraft carriers, nuclear submarines and civilian power generation reactors. Encasing etc. Nuclear-grade zirconium can be regarded as an important strategic metal for the country and is closely related to the development of the nuclear industry.

As an active metal, zirconium forms an oxide film at room temperature. This oxide film gives zirconium and its alloys excellent corrosion resistance. At the same time, zirconium has good mechanical and heat transfer properties, coupled with significant cost advantages, making it an excellent corrosion-resistant structural material in today's petrochemical industry.

The zirconium used in chemical acid and alkali resistant equipment, military industry, and electronics industry is called industrial grade zirconium. In terms of ease of processing, technological level and scientific and technological content, zirconium metal and its alloy products are at the top of the industrial chain.

Zirconium silicate

Zirconium silicate is an important variety in traditional zirconium products. The product uses zircon sand as raw material and can be produced after grinding, calcining and powdering. It is a high-quality and cheap opacifying agent for ceramic glazes. It is mainly used in colored glazes for building ceramics, daily ceramics and electric porcelain. Production, it is also widely used in advanced refractory materials, precision casting, emulsified glass and other industries.

Zirconium carbonate

It is mainly used as additives and waterproofing agents, flame retardants, sunscreens, and surface additives for fibers and papers in cosmetics. It can also be used to prepare zirconium-cerium composite catalytic materials. It is an important raw material in the textile, papermaking, coatings, and cosmetics industries. In recent years, The usage continues to grow.

Zirconium oxychloride

It is the main raw material for the production of other zirconium products such as zirconium dioxide, zirconium carbonate, zirconium sulfate, composite zirconium oxide and the separation of zirconium and hafnium to prepare metal zirconium and hafnium. It can also be used in textiles, leather, rubber additives, metal surface treatment agents, paint desiccants, In recent years, my country's annual output of refractory materials, ceramics, catalysts, fire retardants and other products has exceeded 90,000 tons. Zircon sand is the main raw material of zirconium oxychloride.

Fused zirconia

Referred to as fused zirconium and fused zirconia, it is mainly used to produce glazes and refractory materials. Due to the high impurity content in fused zirconium, its uses are limited.

Zirconium sulfate

It is an important raw material for leather tanning agents, wool treatment agents and paint surface oxidants. It can be used as catalyst carriers, amino acids and proteins, precipitants and deodorants. It is also an intermediate raw material for the preparation of zirconium chemicals and metal zirconium and hafnium.

Zirconium dioxide

Zirconium dioxide all-ceramic is a non-toxic, odorless white solid with sufficient stability to alkali solutions and many acidic solutions. It is suitable for precision ceramics, electronic ceramics, optical lenses, glass additives, electrolyzed zirconium bricks, ceramic pigments, etc. Porcelain enamel, artificial gemstones, refractory materials, grinding and polishing and other industries and products.

Composite zirconia

Also known as semi-stable and stable zirconia, it is a non-toxic, odorless white powder with stable chemical properties and controllable specific surface area. It is the basic raw material for manufacturing various special ceramics, advanced refractory materials, optical communication devices, and new energy materials.

Zirconia structural ceramics

Made of composite zirconia as raw material, it includes zirconia grinding media and zirconia structural parts. The zirconia structural parts mainly include zirconia special ceramic valves, fiber optic connectors, ceramic knives, watch accessories, and ceramic hair scissors. tablets, textile porcelain, etc.

Nuclear grade zirconium

It is mainly used as structural materials for nuclear-powered aircraft carriers, nuclear submarines and civilian power generation reactors, and as cladding for uranium fuel elements. It is an important strategic metal.

Industrial grade zirconium

Industrial grade zirconium is mainly used in the production of chemical acid and alkali resistant equipment, military industry, electronics industry, pipeline valve materials, special high-strength and high-temperature alloy materials, and getters in the electric vacuum and lighting bulb industries.

Firearms Grade Zirconium

Used as sponge zirconium combustion agent for firearms, and also suitable for alloy additives and metallurgical deoxidizers, chemical industry, civilian flash fireworks, etc.

Currently, China and Europe are the main consumer markets for zirconium, with China's demand for zirconium accounting for as high as 52%. China's nuclear power has entered a stage of rapid development, creating demand for nuclear-grade zirconium. At the same time, China is a major producer and exporter of ceramics in the world, and zirconium silicate is the direct and main raw material of the ceramics industry. With the rapid development of China's ceramic industry in recent years, the demand for zirconium has also surged.

Zirconium is not harmful to human health. Zirconia ceramics and various jewelry are widely used in daily life. However, the State Administration for Industry and Commerce has disclosed that zirconium in ceramic tiles can cause cancer.

The relevant announcement issued by the General Administration of Quality Supervision, Inspection and Quarantine announced that three products of two brands failed to meet the "radioactive nuclide limit", which caused a huge stir in the society and caused a huge response in the society and panic about the "tile carcinogen theory".

It is possible for radioactive elements to cause malignant tumors. They generally induce cell lesions and lead to blood cancers such as leukemia, lymphoma, and skin cancer. As for the theory that excessive radioactivity in ceramic tiles causes malignant tumors, Director Chen of the Hematology Department of the First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine said that in his clinical experience and domestic case literature, he has not encountered such cases and related records. However, when it comes to life and health, it is better to be cautious. Therefore, experts recommend that consumers should not blindly pursue whiteness when purchasing ceramic tiles.

The appearance of zircon and diamond is very similar, but the price of zircon and diamond is very different. Some unscrupulous merchants use zircon to pass off as diamond to deceive consumers and make huge profits.

Colorless and transparent zircon is a good substitute for diamonds after careful consideration. The refractive index of zircon is close to 2, and its dispersion is similar to that of diamond. Therefore, in appearance, zircon also sparkles with colored light, much like diamonds. Before the advent of artificial diamonds, zircon was the best substitute for diamonds. At present, zircon has become the leader in mid-to-low-end gemstones, but zircon is cheaper than diamond. It is necessary for consumers to understand the difference between zircon and diamond.

The main identification characteristics of zircon include high refractive index, strong luster, high birefringence, high density, high dispersion and typical spectral characteristics, etc., which results in a very special optical phenomenon. When observed with a magnifying glass, the When the zircon is finished, it can be seen from its top surface that there are obvious double shadows on the bottom surface and ridges. Because diamonds are "homogeneous", there will never be a double shadow phenomenon, so zircon can be distinguished from real diamonds.

Diamond is a homogeneous body, completely black under crossed polarizers and has high hardness; while zircon appears four bright and four dark under crossed polarizers. Diamonds are lipophilic, and ballpoint pens can easily leave uninterrupted traces on the surface of diamonds. Of course, these traces can be easily wiped off. Zircon is not lipophilic, and ballpoint pens cannot leave uninterrupted traces on its surface. Traces of clarity.

At present, among the more than 40 kinds of zirconium and hafnium deposits that have been discovered, only about 10 have industrial mining value, and only two types, zircon and baddeleyite, are used for industrial production.

According to statistics from the United States Geological Survey (USGS) in 2015, global zirconium reserves are 78 million tons, and proven zircon resources exceed 60 million tons (calculated as ZrO2). Among them, Australia and South Africa have the largest share of global zirconium reserves, accounting for Accounting for 65.38% and 17.95% respectively. Other countries with relatively abundant zirconium reserves include India, Mozambique and Indonesia. my country's zirconium resource reserves are relatively scarce, accounting for only 0.6% of the world's reserves.

According to data released by the United States Geological Survey in 2015, global zirconium ore production in 2014 was 1.54 million tons, a year-on-year decrease of 30,000 tons. Australia ranks first in the world with a production of 900,000 tons, accounting for 58.44% of the global total. Followed by South Africa, with an output of 170,000 tons, accounting for 11.03%. The total output of the two countries accounts for 69.47% of the global total, which is difficult for other countries to match. China ranks third with a production of 140,000 tons, accounting for 9.74% of the global total.

Zirconium mineral origins are mainly concentrated in South Australia, Western Australia and New South Wales in Australia, including the Eucla Basin, Geraldton, Murray Basin, and Perth Basin. ) and the Tiwi Islands are the more active zirconium mining areas in Australia today. The Richards Bay Deposit region in South Africa, Florida in the United States, Mozambique in Africa, and Indonesia, Vietnam, and India in Asia all produce a certain amount of zirconium.

Important zirconium producers include Australia's Iluka Company, South Africa's Richards Bay Minerals and South Africa's Exxaro Resources Ltd. China is the main zirconium consumer.

China's zirconium production areas are mainly distributed in Wenchang and Wanning in Hainan and Zhanjiang in Guangdong. In China, only the zircon sand concentrate from Wenchang, Hainan has the best quality, while Wanning and Zhanjiang mainly produce ordinary zircon sand.

HG/T 4694-2014 Industrial high purity zirconium oxychloride

HG/T 3786-2014 Industrial zirconium sulfate

HG/T 3785-2014 Industrial zirconium carbonate

JC/T 2247-2014 Zirconium silicate grinding media balls

JC/T 817-2014 Gem-grade synthetic cubic zirconia crystal

GB/T 30568-2014 Zirconium and zirconium alloy forgings

JB/T 9223-2013 Zirconium sand and powder for casting

YS/T 913-2013 Zirconium and zirconium alloy cakes and rings

HG/T 4545-2013 Zirconium oxychloride production waste recycling method

YB/T 4075-2013 Zirconium sizing nozzle

GB/T 21183-2007 Zirconium and zirconium alloy plates, strips and foils

GB/T 26563-2011 Fused zirconia

GB/T 26931-2011 Zirconium and zirconium alloy scrap

GB/T 26283-2010 Zirconium and zirconium alloy seamless pipes

GB/T 8767-2010 Zirconium and zirconium alloy ingots

GB/T 8769-2010 Zirconium and zirconium alloy rods and wires

GBZ/T 160.26-2004 Determination of toxic substances in workplace air Zirconium and its compounds

HG/T 2773-2012 Zirconium dioxide

HG/T 3785-2005 Industrial zirconium carbonate

HG/T 3786-2005 Industrial zirconium sulfate

JC/T 1094-2009 Zirconium silicate for ceramics

YS/T 402-1994 Zirconium dioxide

YS/T 858-2013 Zirconium concentrate

YS/T 887-2013 Zirconium and zirconium alloy welding wire

High-Purity Zirconium Target

Pure Zirconium Rod