Methods for Zircon Beneficiation

What is Zircon?

Zircon (also known as zircon) is zirconium orthosilicate with a chemical formula of ZrSiO4, which is the most common type of zirconium-containing mineral. Zircon is mainly used as a raw material for zirconate refractory bricks, and can also be used for precision casting sand and ceramic utensils.

What is Zircon Beneficiation?

Zircon beneficiation refers to the process of removing impurities in zircon ore and increasing the content of zircon. Most of the zircon deposits are coastal placers. In the heavy sand containing zircon, there are usually heavy minerals such as magnetite, ilmenite, rutile, and monazite. Generally, when zircon is selected, these heavy minerals are also recovered as target minerals.

What are Zircon Beneficiation Methods?

Zircon beneficiation methods mainly include gravity separation, magnetic separation, electrostatic separation, and flotation.

Methods for Zircon Beneficiation

Gravity separation

Zircon mostly occurs in ilmenite and is often accompanied by heavy minerals such as hematite, chromite, and garnet. Therefore, in the initial stage of enriching zircon, gravity separation is often used, such as using a shaking table to separate heavy minerals from gangue (quartz, feldspar, biotite), etc., and then using other beneficiation methods to separate them from other heavy minerals.


The commonly used collectors in this method are fatty acids (oleic acid, sodium oleate), etc.; the slurry conditioner is sodium carbonate; the inhibitor is sodium silicate; the activator is sodium sulfide and heavy metal salts (zirconium chloride, ferric chloride) ); this method also uses oxalic acid to adjust the pulp to acidity and uses amine collectors for flotation.

Electric selection

Conductive minerals such as ilmenite, hematite, chromite, cassiterite, and rutile are separated from non-conductive minerals such as zircon, monazite, garnet, and apatite by utilizing the difference in mineral conductivity. Desliming, grading, drying, and dosing should be done in advance before electrification.

Magnetic separation

Magnetic minerals in heavy minerals include ilmenite, hematite, chromite, garnet, biotite, monazite, etc. Zircon is a non-magnetic mineral or a weak magnetic mineral (the iron in zircon in some deposits is weak magnetic). Magnetic separation is divided into dry and wet. In dry magnetic separation, the selected materials need to be heated, dried, and classified before they can be sorted. The wet type strong magnetic field magnetic separator has a wide separation particle size, and the lower limit of particle size can reach 20um. Therefore, it is more appropriate to use a wet magnetic separator when the zircon particle size is fine.

Wrap up

Since there are many associated minerals in zircon ore, gravity separation, magnetic separation, flotation, electric separation, and other methods should be used in combination. For more information, please visit

What are Zirconium Containing Refractory Materials?

Description of zirconium-containing refractory products

Zirconium-containing refractory products refer to refractory products made of zirconia (ZrO2) and zircon (ZrSiO4) as raw materials, including zirconia products, zircon products, zirconium mullite, and zirconium corundum products. According to different production processes, zirconium-containing refractory products are divided into sintered products, fused cast products, and non-fired products. Zirconium-containing refractory products have the characteristics of high melting point, low thermal conductivity, and good chemical stability, especially good corrosion resistance to molten glass and liquid metal.

Properties of zirconium-containing refractory products

Dense, stabilized zirconia has a melting point of 2677°C and a service temperature of 2500°C. The bulk density fluctuates between 4.5 and 5.5 g/cm3 due to the purity of the raw materials and the different manufacturing methods. The bulk density of dense zirconia products can reach 5.75g/cm3. Sintered zirconia products do not chemically react with molten metal and liquid glass. Caustic alkali solutions, carbonate solutions, and acids (except concentrated H2SO4 and HF) do not chemically react to zirconia. When carbon reacts with sintered zirconia, zirconium carbide is formed only on the surface. Therefore, under the condition of oxidizing atmosphere, zirconia products can be used at high temperatures without chemical change.

The main component of zircon products is ZrO2•SiO. Zircon is decomposed into ZrO2 and SiO when heated at 1680℃. Quartz stone products have good corrosion resistance to various molten metals, acidic reagents, and liquid glass, but they are prone to erosion reactions when they come into contact with alkaline slag or alkaline refractory materials. Aluminum-zirconium-silicon (AZS) cast bricks and fired bricks have good resistance to glass liquid erosion, and can be used in the pool wall and upper structure of glass melting pool kilns.

zirconium-containing refractory products     

Uses of zirconium-containing refractory products

Zirconium-containing refractory products have high refractoriness, mechanical strength, and chemical stability. It can be widely used in metallurgy, building materials, the chemical industry, machinery, and other professional fields.

Zircon bricks have good resistance to acid slag, small corrosion loss, and slight sticking of slag. They can be used in the slag line of the ladle and have a long service life. Zircon products can also be used as continuous-casting intermediate tank base bricks, cushion bricks, and nozzle bricks. Zircon bricks are corrosion-resistant to low alkali glass and can be used in the kiln walls of glass-melting furnaces. It can also be used for the arch foot of the upper structure of the glass melting furnace or the intermediate transition layer between the silica brick and the corundum brick and is also an important material for the comprehensive masonry bottom.

Zirconia bricks can be used in thermal equipment for the building materials industry and metallurgical industry, such as sizing nozzles for billet continuous casting, submerged nozzles, and slag lines in long nozzles.

Fused-cast bricks with a ZrO2 content of more than 90% can be used for side walls, partition walls and flow holes of borosilicate glass melting furnaces and aluminosilicate glass melting furnaces. AZS-fired bricks and fused cast bricks can be used in soda-lime glass melting kilns, such as flow holes and side walls. The use of this brick to build liquid flow holes and side walls can reduce the contamination of glass liquid by refractory materials. In addition, zirconium mullite fused cast bricks can be used in the metallurgical industry heating furnaces, soaking furnaces, glass melting furnaces in the building materials industry, etc.

For more information, please visit

How to Purify Zirconium Tetrachloride? – 3 Methods

The purification of zirconium tetrachloride is the process of removing the impurities of crude zirconium tetrachloride. Zirconium tetrachloride is generally prepared by chlorination of zirconium carbide, zircon, or zirconium dioxide. At this time, the finished product also contains a considerable amount of impurities such as FeCl3, AICl3, TiCl4, SiCl4, ZrOCl2, and carbon powder. To obtain high-purity zirconium tetrachloride, these impurities must be removed. The mainstream methods for purifying zirconium tetrachloride mainly include the hydrogen reduction method, the molten salt purification method.

Hydrogen Reduction


The basic principles on which this law is based are:

(1) Since Zrcl4 and TiCl4 and SiCI4 have different vapor pressure differences at the same temperature, by controlling a specific temperature, TiCl4, SiCl4 and H2O can be sublimated and removed;

(2) Since ferrous chloride or chromium chloride has a high boiling point (the former is 1303K, the latter is 1573K), trivalent iron and chromium can be reduced to divalent with hydrogen. At the sublimation temperature of ZrCl4 (723-933K), FeCl2, CrCl2 and ZrOCl2 do not sublime and remain in the residue and separate from zirconium.


The purification furnace of the hydrogen reduction method consists of a sublimation furnace and a condenser. The sublimation furnace is a stainless steel container with a cylinder inside, and a multi-layer tray is placed in the cylinder. The zirconium tetrachloride is packed on the tray with an appropriate thickness, and the top of the sublimation furnace is sealed with the condenser to collect the purified ZrCl4.

The work is carried out in three steps.

Step 1

Evacuate the furnace and heat it to a temperature of 423-473K, while the pressure continued to rise. TiCl4, SiCl4, HCI, H2O and adsorbed chlorine gas are discharged out of the furnace by timing exhaust method.

Step 2

Evacuate the furnace and fill it with hydrogen, and raise the temperature to 573K. The iron and chromium in FeCl2 and CrCl2 are reduced to a low-price state.

Step 3

Gradually heat the furnace to 873-933K, and keep the temperature of the condenser at 523K. At this time, ZrCl4 continuously enters the condenser from the sublimation furnace and condenses into a solid, while FeCl3 and CrCl3 do not volatilize and remain in the slag.


The purification operation time depends on the physical state, impurity content and processing volume of the raw materials. 2.0~2.5t ZrCl4 generally needs to be purified for 100~120h, and the recovery rate of zirconium is 97%~98%. The main impurity content (mass fraction ω/%) of refined ZrCl4 is as follows:

Impurities After purification (mass fraction ω/%)
Fe 0.001
Al 0.008
Ti <0.003
Si 0.006

Zirconium(IV) chloride

Molten Salt Purification


The basic principle on which this method is based is that zirconium, iron and aluminum form Na2ZrCl6, K2ZrCl6, NaFeCl4, KFeCl4, NaAlCl4 and KAlCl4 double salts in the NaCl-KCl molten salt system, respectively.

Zirconium double salt can be re-decomposed to ZrCl4 at the set temperature, while Na(K)FeCl4 and Na(K)AlCl4 are stable compounds with high boiling point. Due to the different partial pressures of zirconium salts and iron and aluminum salts at the same temperature, it can be separated from them by controlling a specific temperature to only volatilize ZrCl4. Crude ZrCl4 is purified by washing with molten salt and filtering.


There are two methods of industrial production: intermittent operation and continuous operation.

Intermittent operation

First, make ZrCl4, NaCl, and KCl into molten salt in proportion, remove volatile components at a temperature of 573K, and then raise the temperature of the salt pool to a temperature of 773-873K, so that ZrCl4 is continuously volatilized to the condenser for collection.

Continuous operation

Add the crude ZrCl4 to the molten salt pool with a temperature of 623-723K by a screw feeder for washing and purification, and then transfer the ZrCl4 gas to a bubbling molten salt pool with a temperature of 773-873K for secondary purification. The gaseous product enters the baghouse and condenser for collection.


This method is suitable for processing raw materials with high iron and aluminum impurities. The main impurity content (mass fraction ω/%) of ZrCl4 product after purification is:

Impurities After purification (mass fraction ω/%)
Fe 0.01~0.002
Al 0.003~0.008
Ti 0.002~0.009
Si 0.002~0.008。

Liquid Purification Method

In addition to the above two mainstream purification methods, there is also a liquid purification method. The process is to pass hydrogen and nitrogen mixed gas into the bottom of the purification furnace with a structure similar to that of the fluidized chlorination furnace, so that the coarse ZrCl4 powder in the furnace forms a fluidized layer, and trivalent chlorides such as iron and chromium are reduced to two due to reduction. The high boiling point chlorides remain in the slag and separate from ZrCl4. The refined ZrCI4 gas enters the condenser for cooling and collection after being filtered.

For more information about zirconium tetrachloride or othe

zirconium products, please visit

Introduce Several Kinds of Zirconium Ores

Zirconium is abundant in the earth’s crust, and the natural silicate ores containing zirconium are called zircon or hyacinth. Since zirconium and hafnium have similar properties, zirconium and hafnium in nature always coexist, and the hafnium coexisting with zirconium generally only accounts for 1%-2% of the weight of zirconium and hafnium.

Zirconium metal and zirconium compounds

Zirconium metal has unique nuclear properties and is an important material for nuclear reactors. More than 90% of zirconium metal is used in nuclear reactions, as fuel tanks in nuclear power plants and as packaging materials for atomic fuel in nuclear-powered ships. In addition, zirconium metal has a series of properties, such as good heat resistance, plasticity, and corrosion resistance, and is widely used in electronics, chemistry, metallurgy, steel, defense, and other industries.

Zirconium compounds also have excellent physical and chemical properties and are widely used in ceramic knives, grinding media, precision machining and casting, optical glass, optical fibers, electronic ceramics, precision ceramics, petroleum cracking, jade processing, aerospace and other fields.

Major deposits of zirconium

1) Seaside placer type, such as mines on the east coast of Australia.

This type of deposit is often formed in the wave strike zone of the seashore, and is distributed in a narrow and long manner along the seashore, extending from several kilometers to more than 100 kilometers, and the thickness is generally tens of centimeters. Due to coastal changes, some deposits have become buried deposits. In addition to zircon, heavy minerals often contain ilmenite, rutile, monazite, etc., which can be comprehensively utilized.

2) Anisotropic nepheline-bearing syenite deposits, such as the Kola Peninsula Khibiny deposit in Russia, etc.

3) Zirconium-bearing albite alkaline rock deposits. Ore minerals are mainly spar, zircon, water zircon, etc., and other symbiotically available minerals.

Zirconium Ores

Mineral composition of zirconium

Zirconium and zirconium-related products are almost entirely supplied by zircon and baddeleyite, with zircon being the main mineral. The color of zircon varies from colorless to a variety of colors including pale yellow, brownish yellow, orange-yellow, reddish brown, and brown, and some zircon form crystals with gemstone properties.

Physical and chemical properties of zircon

Zircon is zirconium orthosilicate and its molecular formula is ZrSiO4. Pure zircon is rare in nature, and most of them contain impurities such as iron, chromium, aluminum, and calcium.

Zircon has a Mohs hardness of 7-8, a tetragonal system, metallic luster or vitreous luster, and is generally transparent or opaque in brown, light gray, yellow, blue, etc. Weakly conductive, non-magnetic, or weakly magnetic. Zircon is generally insoluble in acids and alkalis.

How to Prepare Zirconium Silicide Nanomaterials?


Zirconium silicide is a steel gray orthorhombic shiny crystal. It is insoluble in water, mineral acids, and aqua regia, and soluble in hydrofluoric acid. Zirconium silicide is an excellent ceramic material with high hardness, high melting point, high electrical conductivity, high thermal conductivity, and excellent thermal shock resistance. Because of these advantages, it can be applied to structural materials or new engineering materials for high-temperature corrosive media.


Zirconium silicide nanomaterial can be obtained by reacting a mixture of zirconium oxide powder, silicon powder and lithium in a proportioned amount at a high temperature in the absence of air. Specific steps are as follows:

(1) Add 5mmol zirconium dioxide, 5mmol silicon powder and 50mmol metallic lithium in a 20-milliliter stainless steel autoclave, then put the autoclave into an electric furnace.

2) Set the heating rate of the electric furnace to 10 °C per minute, and heat the electric furnace to 600 °C.

3) After the temperature was raised to 600°C, the temperature was maintained for 40 hours to ensure that the raw materials were fully reacted.

4) After the reaction was completed, naturally cool down the autoclave to room temperature, and then open the autoclave and take out the black deposit.

5) Wash the deposit with distilled water once, and then wash with dilute hydrochloric acid and absolute ethanol once respectively.

6) Filter the washed deposit, and then dry it in a vacuum drying oven at 60° C for 4 hours to obtain a zirconium silicide nanomaterial.

Zirconium Silicide Powder

The above reaction process is represented by the following equation:


According to the quality of the prepared zirconium silicide nanomaterials and the quality of the used raw material zirconium dioxide, the method obtains that the yield of zirconium silicide is 85%.


Zirconium silicide nanomaterial can be used to prepare a high-density ceramic matrix composite material: zirconium diboride-zirconium disilicide-tungsten carbide ceramic matrix composite material. This material is prepared from zirconium diboride powder, zirconium disilicide and tungsten carbide (purity >98.0%) using a two-step hot pressing sintering process. Wherein, the mass fraction of zirconium diboride powder is 75-90%, the mass fraction of zirconium disilicide is 10-15%, and the mass fraction of tungsten carbide is 0-10%. Adding a higher content of zirconium diboride to the ceramic matrix composite material is beneficial to improve the physicochemical properties of the composite material; adding this appropriate amount of zirconium disilicide to the ceramic matrix composite material can significantly reduce the sintering temperature for material preparation; the added tungsten carbide can promote anisotropic growth of grains inside the material.

For more information about platinum, please visit

Zircon and Zircon Sand (Zr2SiO4)

Zircon sand, also known as zircon, is a mineral mainly composed of zirconium silicate (Zr2SiO4). Pure zircon is colorless and transparent crystal; depending on the origin, type, and quantity of impurities, zircon sand may appear in yellow, orange, red, brown, and other colors. The uniform Mohs hardness of zircon is 7-8, the refractive index is 1.93-2.01, and the melting point fluctuates within 2190-2420 ℃ with different impurities.

Chemical Composition

The main chemical composition of zircon is ZrO2 & SiO2, and a small amount of impurities such as Fe2O3, CaO, AI2O3, etc. The theoretical composition of zircon sand is ZrO2: 67.1%; SiO2: 32.9%. It is the only compound in the ZrO2-SiO2 system. But natural zircon sand only contains about 57~66% ZrO2.


Zircon is a mineral composed primarily of zirconium, silicon, and oxygen that crystallized out of magma when igneous rocks formed. It is the most important zirconium-bearing mineral – it is the most widely distributed, the most abundant, and the most types of zirconium minerals. Zircon belongs to the tetragonal crystal system, often in the form of well-developed cone-shaped small square cylinders, and also irregular granular. It is brittle and has a shell-like fracture. It is mostly symbiotic with ilmenite, rutile, monazite, xenotime, etc. in the coastal sand.

Zircon Sand


Zircon is the main raw material for the preparation of zirconium, hafnium and various zirconium products. It is also a high-quality refractory material with high melting point, low thermal conductivity and small linear expansion coefficient, and is widely used in metallurgy, casting and other industries.

The addition of zircon to other materials can improve their performance. For example, adding zircon sand to synthetic cordierite can broaden the sintering range of cordierite without affecting its thermal shock stability; Adding zircon sand to high-alumina bricks to manufacture anti-stripping high-alumina bricks, the thermal shock stability is greatly improved; It can also be used to extract ZrO2.

More specific applications are as follows:

Refractory: zirconium refractory, such as zirconium corundum brick, zirconium refractory fiber;

Sand for casting mold in the foundry industry: molding sand for precision casting, precision enamel utensils;

Glass, metal: sponge zirconium;

Production of zirconium compounds: such as zirconium dioxide, zirconium oxychloride, sodium zirconate, potassium fluorozirconate, zirconium sulfate, etc.

If you are interested in other zirconium materials, please visit

Separation of Zirconium and Hafnium by Solvent Extraction

Solvent extraction of zirconium and hafnium is one of the common methods for separating zirconium and hafnium. Compared with other zirconium and hafnium separation methods (such as pyrolysis separation and solvent extraction separation), this method has the advantages of large production capacity, simple process and easy to achieve continuously.


The extraction agents used for the separation of zirconium and hafnium mainly include ketone extractants, neutral phosphorus-containing extractants and amine extractants.

A commonly used ketone extractant is methyl isobutyl ketone (MIBK), which can form a neutral extract with hafnium thiocyanate and is preferentially extracted into the organic phase.

Methyl isobutyl ketone 3D ball
Methyl isobutyl ketone 3D ball. Source: Wikipedia

A typical neutral phosphorus-containing extractant is tributyl phosphate (TBP), which is preferentially extracted into the organic phase through the coordination of oxygen atoms in chemical bonds with zirconium metal atoms to form a neutral extract compound Zr(NO3)4•2TBP.

Ball and stick model of Tributyl phosphate
Ball and stick model of Tributyl phosphate. Source: Wikipedia

The commonly used amine extractant is trioctylamine (TOA). Trioctylamine forms an extract with zirconium ions in an acidic medium, and is preferentially extracted into the organic phase.

Process flow

There are three extraction processes: MIBK, TBP, and N235.

MIBK extraction

It uses ZrCI4 as raw material, adds water and NH4CNS ingredients. MIBK preferentially extracts hafnium, leaving a large amount of zirconium in the aqueous phase. This is the earliest extraction process used to separate zirconium and hafnium, and it is adopted by major producers of zirconium and hafnium such as the United States, France, Germany, and Japan.

TBP extraction

There are two aqueous feed systems for this process: nitric acid, and a mixed acid of nitric & hydrochloric acid. The former is to convert the product of zircon decomposed by alkali fusion method into nitric acid aqueous phase feed liquid, and use TBP to preferentially extract zirconium; the latter use Zr-CI4 as raw material, add water, nitric acid and hydrochloric acid as ingredients, and then use TBP to preferentially extract zirconium.

The separation coefficient of zirconium and hafnium in the TBP extraction process is large, and the number of extraction stages is small, and atomic-level zirconium oxide and hafnium oxide can be obtained at the same time. However, the water-phase feed liquid is highly corrosive, and the emulsification problem in the extraction process has not been completely solved, thus affecting its popularization and application.

N235 extraction

First, the zircon is decomposed by alkali fusion method, and the product is washed with water to remove silicon, and then leached with sulfuric acid to obtain a sulfuric acid solution of zirconium, and then the zirconium is preferentially extracted with N235. After washing, atomic-level zirconia containing hafnium <0.01% can be obtained. The hafnium in the raffinate is enriched to 50% to 70%, and then extracted by P204, and the zirconium and hafnium are further separated to obtain atomic energy level hafnium oxide containing more than 96% of hafnium.

This process has low material toxicity, light equipment corrosion, stable operation, and easy disposal of waste, so it is currently recognized as one of the best extraction processes.

Extraction equipment

There are two main types of extraction equipment, one is the extraction tower, and the other is the box-type mixer-settler. The former is used by the MIBK process, and the latter is used by TBP and N235 extraction process. The extraction tower occupies a small area and has a large production capacity. The box-type mixer-clarifier is simple in structure and stable in operation, and is generally made of acid-resistant materials such as plastic or plexiglass.

For more information, please visit

3 Methods to Separate Zirconium & Hafnium

The two elements of zirconium and hafnium are symbiotic resources, which means that zirconium generally contains 0.5% to 2% of hafnium. However, the application of zirconium products in various industries requires high purity. For example, zirconium, which is a structural and cladding material for nuclear reactors, must contain less than 0.01% hafnium. In general, the metallurgical process of separating zirconium and hafnium is an important part of the zirconium metallurgical process.

The separation methods of zirconium and hafnium include pyrolysis separation, solvent extraction separation, and ion exchange separation. This article will briefly introduce these three separation methods.

Zirconium and Hafnium Pyrolysis Separation

Pyro separation is a method of separating zirconium and hafnium at high temperature or high pressure by using the difference in vapor pressure of zirconium and hafnium chloride. Zirconium and hafnium pyrolysis can replace the three production stages of extraction, calcination and chlorination in common separation methods. It has the characteristics of a short production process, high efficiency, low reagent cost and light pollution to the environment, and is a promising method for separating zirconium and hafnium.

The pyrolysis method is mainly realized by high-pressure rectification and molten salt rectification. High-pressure rectification is a process of directly separating zirconium and hafnium by using the difference in vapor pressure of Zrcl4 and HfCl4. Molten salt rectification is a process of separating zirconium and hafnium in a rectifying tower by using the difference in saturated vapor pressure of ZrCl4 and HfCl4 in KAlCl4 molten salt.

3 Methods to Separate Zirconium & Hafnium

Zirconium and Hafnium Solvent Extraction

This is a method for the separation of zirconium and hafnium using solvent leather. Compared with other separation methods of zirconium and hafnium, this method has the advantages of large production capacity, simple process, and easy to achieve continuously. It is the most important method for the separation of zirconium and hafnium.

The reagents used in this method mainly include ketone extractant, neutral phosphorus-containing extractant and amine extractant. There are three extraction processes of MIBK, TBP and N235. There are two main types of extraction equipment, one is the extraction tower, and the other is the box-type mixer-settler. The former is used by the MIBK process, and the latter is used by TBP and N235 extraction process. The extraction tower occupies a small area and has a large production capacity. The box-type mixer-clarifier is simple in structure and stable in operation, and is generally made of acid-resistant materials such as plastic or plexiglass.

Further Reading: Separation of Zirconium and Hafnium by Solvent Extraction

Zirconium and Hafnium Ion Exchange Separation

As the name suggests, this is a method for the separation of zirconium and hafnium by ion exchange. The production volume of this method is small. Only the former Soviet Union has used it to further separate zirconium and hafnium from the hafnium-rich material separated by the zirconium-hafnium recrystallization method to obtain hafnium oxide, which is used as the raw material for the production of atomic-level sponge hafnium.

For more information, please visit

2 Methods of Refining Zirconium

Zone melting and purification

This method does not use crucibles, so it can largely protect the product from contamination by the crucible.

The process of zirconium zone smelting and purification generally includes three stages: raw material preparation, zone smelting and product quality inspection.

Stage 1 Prepare raw materials

The sponge zirconium or zirconium iodide is made into rods by electron beam melting, extrusion, machining and other steps.

Stage 2 Zone smelting

Fix the zirconium rod vertically in the vacuum chamber, use the high-frequency induction coil (or electron gun) as the heat source to melt one end of the rod into a melting zone, and then slowly move the melting zone from one end to the other.

Zirconium is a high melting point metal with strong chemical activity. The vapor pressure at its melting point of 2125K is low, and zone smelting is easier to carry out at this time.

The main factors affecting this stage are the purity of raw materials, vacuum pressure, zone melting speed and zone melting times.

Schematic representation of the zone melting process with single heater. Curtolo, Danilo & Friedrich, Semiramis & Friedrich, Bernd. (2017). High Purity Germanium, a Review on Principle Theories and Technical Production Methodologies. Journal of Crystallization Process and Technology. 07. 65-84. 10.4236/jcpt.2017.74005.

Stage 3 Inspect Product Quality

The head and tail sections of the zirconium rod obtained in the previous stage were excised for sampling. Its various parameters are measured by mass spectrometry, hardness determination or specific resistance.

E-beam melting and purification

Zirconium has a great affinity for oxygen and nitrogen, and 0.2% nitrogen or oxygen in zirconium becomes brittle, making it difficult to process into materials. In this method, the metal to be purified is bombarded with electrons in a vacuum to melt it. In the purification process, in addition to avoiding the oxidation and nitridation of zirconium, the gas dissolved in the zirconium can also escape, the mixed oxide can be decomposed or evaporated, and metal impurities (such as copper, aluminum, gold, iron, manganese, chromium, etc.). The processing properties, electrical properties, magnetic properties and mechanical properties of the zirconium ingot purified by electron beam smelting are obviously better than the raw zirconium.

Scheme of Electron beam melting and refining (EBMR) process
Scheme of Electron beam melting and refining (EBMR) process. Vutova, Katia & Donchev, Veliko. (2013). Electron Beam Melting and Refining of Metals: Computational Modeling and Optimization. Materials. 6. 4626-4640. 10.3390/ma6104626.

An electron beam melting furnace is composed of an electron gun system, furnace body, vacuum system, raw material adding system, mold mechanical device, operation control system, and high voltage power supply device. The larger the scale is, the lower the product smelting cost is. At present, the smelting process is developing into a semi-continuous or continuous production mode to improve production efficiency and production capacity.

The quality of zirconium ingot purified by electron beam melting depends on the raw material, the melting speed, and the power of the melting furnace.

For more information, please visit

3 Types of Zirconium Based Getter Materials

Zirconium-based getter material refers to the alloy with high absorption active gas characteristics formed by adding other elements based on zirconium.

Before sealing in vacuum tubes and devices, the material must be heated and activated under vacuum conditions for fast and effective gettering. The function of activation is to remove the passivation film formed on the surface during the manufacturing and storage process to expose the fresh surface, which is conducive to the overall gettering, so as to achieve the purpose of absorbing a large amount of oxygen, nitrogen, hydrogen, carbon monoxide, carbon dioxide, hydrocarbons, and water vapor.

Zirconium-aluminum alloy, zirconium-graphite, and zirconium-vanadium-iron alloy are widely used zirconium-based getter materials today.

Zirconium-aluminum alloy getter

Zirconium-aluminum alloy getter can be made into ring-shaped material and composite strip-shaped material.

(1) Ring-shaped material. The material has poor gettering performance at room temperature and is usually not used for gettering at room temperature. This material is commonly used in electronic tubes, various vacuum devices, special lamps, inert gas purification, zirconium-aluminum getter pumps, etc.

(2) Composite strip material. The advantage is that the amount of mercury can be accurately controlled, and it does not decompose or generate mercury vapor below 500°C, thereby greatly reducing environmental pollution, preventing workers from mercury poisoning, and improving lamp quality and life. It has been widely used in fluorescent lamps and energy-saving lamps.

ZR1422 Zirconium Aluminum Alloy, ZrAl Alloy
ZR1422 Zirconium Aluminum Alloy, ZrAl Alloy

Zirconium graphite getter

Zirconium graphite getter is often used in high-reliability and long-life vacuum tubes and devices for long-term operation and storage, such as traveling wave tubes, X-ray tubes, trigger tubes, ceramic tubes, and laser tubes.

Zirconium-vanadium-iron alloy getter

Zirconium-vanadium-iron alloy getter is a low-temperature activated getter material composed of zirconium, vanadium, and a small amount of iron. It is divided into two types:

(1) Zirconium vanadium ferroalloy getter material, smelted by 70%zr+24.6%V+5.4%Fe in electric arc furnace or medium frequency induction furnace under vacuum or filled with inert gas, then crushed, pulverized, and then pressed into getter elements.

(2) (Zirconium vanadium ferro)/zirconium getter material. It is made by adding the zirconium vanadium ferroalloy powder prepared in (1), adding zirconium powder in a certain proportion, mixing evenly, and then pressing, high temperature and high vacuum sintering and other processes. into a suction element. Product forms are powder, flakes, rings, and strips.

These two zirconium-vanadium-iron alloy getters are low-temperature activated getters, and the activation process is as follows: the temperature is 400-600°C, the vacuum degree is 10-2-10-4Pa, and the maintenance is 10-30min. The working temperature is from room temperature to 350℃.

Zirconium-vanadium-iron alloy getter is widely used in stainless steel vacuum insulated cups (bottles), solar vacuum water heaters, high-efficiency oil-insulated pipes, and vacuum tube containers that are only allowed to operate at 500°C.

For more information, please visit