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Zircon FLOUR

Grade

FLOUR = zircon sand / milled zircon flour

Choose as raw material: ceramic-glaze opacifier, investment-casting facecoat and foundry sand, or feedstock for zirconia production.

Standard cost $$

Values for the FLOUR condition

Other Zircon tempers and conditions

Zircon is listed in 4 conditions; see the grade overview at Zircon.

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Bonded zircon refractory brick / shape
Choose for glass-tank paving, ladle and slide-gate refractories where slag/glass corrosion resistance matters more than strength.———900 HV3 W/m·K
Fused-cast / electrofused zircon
Choose for glass-furnace throat and paver blocks or high-grade refractory grain where maximum density and glass-corrosion resistance are required.———1,100 HV4 W/m·K
C728Default
Dense sintered zircon porcelain
Choose for gas-tight, high-strength electrical/thermal ceramic parts: insulators, nozzles, thermocouple sheaths, foundry tooling.———1,150 HV5 W/m·K
FLOURThis page
Zircon sand / milled zircon flour
Choose as raw material: ceramic-glaze opacifier, investment-casting facecoat and foundry sand, or feedstock for zirconia production.——01,200 HV5 W/m·K

What is Zircon FLOUR?

Zircon FLOUR is Zircon in the FLOUR grade — choose as raw material: ceramic-glaze opacifier, investment-casting facecoat and foundry sand, or feedstock for zirconia production. Zircon FLOUR has a tensile strength of 80 MPa (11.6 ksi), weaker than 53% of ceramic grades. The elastic modulus is 230 GPa (33.4 Msi). Zircon FLOUR has a density of 4.65 g/cm³ (0.168 lb/in³), lighter than 54% of ceramic grades. It melts at 1,687°C (3,069 °F). C728 is the default condition FabDigit quotes; FLOUR is available on request or by drawing note.

Advantages

  • High service temperature — 1,650°C (3,002 °F), better than 88% of ceramic grades
  • Low embodied carbon — 3 kg CO₂/kg, better than 88% of ceramic grades
  • Good corrosion resistance — 90/100, better than 81% of ceramic grades

Zircon FLOUR properties

Typical room-temperature values for Zircon FLOUR; 14 are specific to this condition. Other listed values are Zircon reference data and may not represent this condition. Bars are the position among ceramic grades.

Physical4

Zircon FLOUR has a density of 4.65 g/cm³ (0.168 lb/in³), lighter than 54% of ceramic grades. It melts at 1,687°C (3,069 °F).

Density4.65 g/cm³0.17 lb/in³
Melting Point (Solidus)1,687°C3,069 °F
Refractive Index1.95
Porosity0.2%

Mechanical11

Zircon FLOUR has a tensile strength of 80 MPa (11.6 ksi), weaker than 53% of ceramic grades. The elastic modulus is 230 GPa (33.4 Msi).

Elastic (Young's) Modulus230 GPa33.4 Msi
Shear Modulus78 GPa11.3 Msi
Bulk Modulus150 GPa21.8 Msi
Poisson's Ratio0.25
Tensile Strength (Ultimate)80 MPa11.6 ksi
Compressive Strength1,500 MPa218 ksi
Flexural Strength180 MPa26.1 ksi
Fracture Toughness (K_IC)1.8 MPa·√m1.6 ksi·√in
Hardness, Vickers1,200 HV
Hardness, Knoop1,100 HK
Hardness, Mohs7.5

Thermal5

Zircon FLOUR is rated for continuous service to 1,650°C (3,002 °F). It conducts heat at 5.1 W/m·K (2.95 BTU/hr·ft·°F), worse than 61% of ceramic grades. Thermal expansion is 4.2 µm/m·K (2.33 µin/in·°F).

Thermal Conductivity5.1 W/m·K2.9 BTU/hr·ft·°F
Specific Heat Capacity560 J/kg·K0.13 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)4.2 µm/m·K2.3 µin/in·°F
Max Service Temperature (continuous)1,650°C3,002 °F
Min Service Temperature-200°C-328 °F

Electrical5

Zircon FLOUR is an electrical insulator with a dielectric strength of 12 kV/mm (304.8 V/mil) and a resistivity of 1×10¹¹ Ω·m.

Electrical Resistivity1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in
Dielectric Strength12 kV/mm305 V/mil
Dielectric Constant (1 MHz)9
Dissipation Factor (1 MHz)0.001
Volume Resistivity1×10¹³ Ω·cm

Chemical & Environmental2

Corrosion resistance is excellent (90/100), better than 81% of ceramic grades.

Corrosion ResistanceExcellent90/100
Chemical Resistance SummaryVery resistant to acids (except HF and hot concentrated H2SO4), to molten glass and to most metal melts and slags; attacked by strong alkalis, alkali carbonates and fluorides at high temperature; above ~1676 °C it dissociates into ZrO2 + free SiO2.

Sustainability4

Producing a kilogram of Zircon FLOUR takes about 40 MJ of energy and emits 3 kg of CO₂ — less than 88% of ceramic grades. Typical recycled content is 3%.

Embodied Energy (primary production)40 MJ/kg17,197 BTU/lb
Embodied Carbon (primary production)3 kg CO₂/kg
Embodied Water30 L/kg3.6 gal/lb
Typical Recycled Content3%

Manufacturability3

Zircon FLOUR's machinability is not recommended (3/100, worse than 95% of ceramic grades).

MachinabilityNot recommended3/100
PolishabilityVery good80/100
Sintering / Firing Temperature1,600°C2,912 °F

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Zircon FLOUR

Is Zircon easy to machine?

Green or bisque bodies machine easily with carbide tooling; after firing only diamond grinding, lapping and ultrasonic/laser machining are practical.

Can Zircon be welded?

Not weldable — join by ceramic-to-metal brazing (Mo-Mn metallizing), glass frit sealing or high-temperature cements.

Can Zircon be formed, bent or molded?

Formed by dry pressing, isostatic pressing, slip casting or extrusion of milled zircon flour with clay/binder, then fired at 1500–1700 °C; allow ~12–18 % firing shrinkage.

What surface finishes work on Zircon?

Diamond grind and polish for sealing faces; glazing improves surface sealing and thermal-shock-crack resistance; no plating or anodizing applies.

Zircon chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

ElementSpec limit (wt %)Nominal
ZrO2ZrO2+HfO2 basis; stoichiometric ZrSiO4 = 67.2 % ZrO264 – 67.266
HfO2naturally substitutes for Zr; usually reported inside ZrO20.8 – 1.81.2
TiO2impurity from rutile≤ 0.20.08
Fe2O3impurity≤ 0.150.05
Al2O3impurity / bond phase≤ 0.60.25
U+Th (trace)natural radionuclides — relevant to NORM handling rules≤ 0.050.02
SiO2stoichiometric 32.8 %≥ 31.5 (balance)—

Zircon FLOUR — frequently asked

What is Zircon FLOUR used for?

Zircon FLOUR is typically used for foundry sand/refractories, ceramic glaze opacifier, kiln furniture, investment casting shell and raw material for ZrO2 production. In short: low-expansion refractory silicate; 1500 °C service capability; feedstock for zirconia.

What is the tensile strength of Zircon FLOUR?

Zircon FLOUR has a typical tensile strength of 80 MPa (11.6 ksi) — weaker than 53% of ceramic grades. Strength varies by condition: see the 4 listed tempers.

Is Zircon FLOUR easy to machine?

Not especially — machinability is rated not recommended (3/100, worse than 95% of ceramic grades). Green or bisque bodies machine easily with carbide tooling; after firing only diamond grinding, lapping and ultrasonic/laser machining are practical.

Can Zircon FLOUR be welded?

Not weldable — join by ceramic-to-metal brazing (Mo-Mn metallizing), glass frit sealing or high-temperature cements.

What surface finishes work on Zircon FLOUR?

Diamond grind and polish for sealing faces; glazing improves surface sealing and thermal-shock-crack resistance; no plating or anodizing applies.

Can Zircon FLOUR be formed, bent or molded?

Formed by dry pressing, isostatic pressing, slip casting or extrusion of milled zircon flour with clay/binder, then fired at 1500–1700 °C; allow ~12–18 % firing shrinkage.

What is the maximum service temperature of Zircon FLOUR?

Zircon FLOUR is rated for continuous use to about 1,650°C (3,002 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Sources

  1. ANSI/ASTM C728 — Standard Specification for Zircon Porcelain (technical ceramic classification) — ASTM International (2019)
  2. ASM Engineered Materials Handbook, Vol. 4: Ceramics and Glasses — ASM International (1991)
  3. Handbook of Refractory Practice / Refractories Handbook (zircon and zircon-bonded products) — Harbison-Walker / CRC (2005)
  4. GB/T 21114 — X (used for zircon assay); GB/T industry grades — SAC (2019)
  5. Technical zircon ceramic and fused-cast zircon datasheets — CoorsTek / Saint-Gobain / Iluka Resources (2023)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.