3 Manufacturing Methods of Zirconium-containing Refractories

What is Zirconium-containing Refractory Material?

Zirconium-containing refractory materials are made of zirconia (ZrO2) and zircon (ZrSiO4) as raw materials. “Zirconium-containing” usually refers to materials containing the following zirconium products: zirconia, zircon, zirconium mullite and zirconium corundum. Zirconium-containing products have good corrosion resistance to various molten metals, acidic reagents and liquid glass.

Zirconium-containing refractory materials can be divided into the sintered, fused cast, and non-fired products based on different manufacturing methods.

What are the Different Manufacturing Methods?

Sintered Zr-Containing Refractory Product

The basic steps to manufacture zirconium-containing sintered bricks are to prepare raw materials, press green bodies, and sinter at high temperatures.

Another method is to obtain blanks by granulation, kneading, machine pressing or extrusion molding, and the clinker fired at high temperature is used as aggregate, and the clinker fine powder is used for batching, kneading, molding, drying, and sintering to finally obtain the finished product.

Cast Zr-Containing Refractory Product

1) Use zircon concentrate or industrial zirconia and industrial alumina powder as raw materials.

2) Add sodium oxide, calcium oxide, boron oxide and rare earth metal oxides as additives.

3) The powder is melted at a temperature above 2500°C by means of electric arc melting, cast in a mold, cooled, annealed, and machined.

Non-fired Zr-Containing Refractory Product

The manufacturing process of zirconium-containing refractory products without firing is simple, and the product qualification rate is high.

1) Use stabilized zirconia clinker or zircon as raw material.

2) Use water glass, phosphoric acid, phosphate, or sulfate as the cementing agent.

3) Mix the raw materials and cementing agents, and undergo high-pressure molding and low-temperature heat treatment to make zirconium-containing non-fired materials.

The heat treatment temperature varies with different binders. When aluminum dihydrogen phosphate is used as the cement, the heat treatment temperature is about 300°C; when phosphoric acid is used as the cement, the heat treatment is carried out at a temperature of about 600°C.

What Are These Products Used for?

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

  • Zirconia bricks can be used in thermal equipment in the building materials industry and metallurgical industry, such as billet continuous casting sizing nozzles, submerged nozzles and slag lines in long nozzles.
  • Zircon bricks are resistant to low-alkali glass corrosion. They can be used for the kiln wall of the glass melting furnace, as well as the arch feet of the upper structure of the glass melting furnace or the intermediate transition layer between silica bricks and corundum bricks.
  • Zirconia-mullite fused cast bricks can be used in heating furnaces, soaking furnaces in the metallurgical industry, glass melting furnaces in the building materials industry, etc.
  • Zirconium corundum bricks have good resistance to melt erosion. As a high-grade abrasive, it has a good grinding effect on steel, cast iron, heat-resistant steel, and various alloy materials.

If you want to know more about zirconium material, we would like to advise you to visit Stanford Advanced Materials (SAM) for more information.


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 https://www.samaterials.com/70-zirconium.html.

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.

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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.

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.

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