Trace Metal Controlled Square Quartz Crucibles - TOQUARTZ®
Properties of Square Quartz Crucibles
Purity & Chemical Inertness
- SiO₂ content is certified at ≥99.98% per batch
- Total trace metals are held below 20 ppm
- Iron content is maintained below 2 ppm in every production lot
Continuous Service Temperature
- Square quartz crucibles are rated to 1100 °C in continuous operation
- Short-term peaks of 1300 °C are tolerated for up to 60 minutes
- Structural integrity is maintained across repeated thermal cycles.
Furnace Space Utilisation
- A square footprint covers approximately 98% of shelf area.
- Round crucibles utilise only 78% of the same space.
- Batch capacity is increased by 40–50% over round crucibles.
- Excellent Thermal Stability
- Thermal Shock Resistance
- Inert Chemical Resistance
Dimensions & Technical Specifications of Square Quartz Crucibles
Size of of Square Fused Quartz Crucibles
| Model | Length (mm) | Width (mm) | Height (mm) | Wall Thickness (mm) | Purity |
| AT-QTZ-C001 | 50 | 10 | 10 | 2-3 | 99%-99.99% |
| AT-QTZ-C002 | 100 | 10 | 10 | 2-3 | 99%-99.99% |
| AT-QTZ-C003 | 50 | 15 | 10 | 2-3 | 99%-99.99% |
| AT-QTZ-C004 | 100 | 15 | 10 | 2-3 | 99%-99.99% |
| AT-QTZ-C005 | 50 | 20 | 15 | 2-3 | 99%-99.99% |
| AT-QTZ-C006 | 100 | 20 | 15 | 2-3 | 99%-99.99% |
| AT-QTZ-C007 | 50 | 30 | 20 | 2-3 | 99%-99.99% |
| AT-QTZ-C008 | 100 | 30 | 20 | 2-3 | 99%-99.99% |
| AT-QTZ-C009 | 50 | 40 | 25 | 2-3 | 99%-99.99% |
| AT-QTZ-C010 | 100 | 40 | 25 | 2-3 | 99%-99.99% |
| AT-QTZ-C011 | 50 | 50 | 30 | 2-3 | 99%-99.99% |
| AT-QTZ-C012 | 100 | 50 | 30 | 2-3 | 99%-99.99% |
| AT-QTZ-C013 | 50 | 50 | 50 | 2-3 | 99%-99.99% |
| AT-QTZ-C014 | 100 | 100 | 30 | 2-3 | 99%-99.99% |
| AT-QTZ-C015 | 100 | 100 | 50 | 2-3 | 99%-99.99% |
| AT-QTZ-C016 | 100 | 100 | 100 | 2-3 | 99%-99.99% |
| AT-QTZ-C017 | 200 | 100 | 50 | 2-3 | 99%-99.99% |
Technical Specifications of Square Quartz Crucibles
| Chemical Composition & OH Content |
(ppm) | Cr | Ge | Fe | Mg | Ti | Ca | Al | Na | Li | K | OH |
| 20 | 0.4 | 1.5 | 0.4 | 100 | 1 | 16 | 2.3 | 0.5 | 2 | ＜25 | ||
| Physical Properties | Property | Value | Property | Value | Property | Value | Property | Value | Property | Value | Property | Value |
| Density (20°C) | 2.2 × 10³ kg·m⁻³ | Coefficient of expansion (25-300°C) | 0.56 × 10⁻⁶ °C⁻¹ | Softening point | 1630°C | Annealing point | 1180°C | Strain point | 1100°C | Young’s modulus | 7.3 × 10⁵ Pa | |
| Spectral Transmission at 1.0mm Thickness (%) | ＜220nm | 230-280nm | 290-330nm | 350nm | 450nm | 550nm | 590nm | 780nm | ||||
| 0 | ＜15 | 0 | 15 | 88 | 92 | 93 | 93 | |||||
TOQUARTZ® Solving Challenges with Square Quartz Crucibles
Square Quartz Crucible for Battery Cathode Material Calcination
Key Advantages
- Fe content is held below 2 ppm per batch COA.
- SiO₂ purity is certified at ≥99.98% per shipment.
- Matched lids are fitted to ±0.1 mm of the crucible rim.
TOQUARTZ® solution
Dimensional deviation in crucible lids causes atmosphere leakage during N₂ and Ar calcination. Lid-to-body fit is guaranteed at ±0.1 mm on all TOQUARTZ® square quartz crucibles. Atmosphere integrity is maintained without external fixturing or sealing tape.
Square Quartz Crucible for Coal and Mineral Ash Determination
Key Advantages
- Service life is rated at ≥50 thermal cycles at 815 °C.
- CTE is held at ≤0.55 × 10⁻⁶ /°C from 25 to 1000 °C.
- Trace metal background is maintained below 20 ppm total.
TOQUARTZ® solution
Low-density quartz crucibles deform after 8–12 cycles at 815 °C in daily ash analysis service. TOQUARTZ® square quartz crucibles are fabricated from dense arc-fused silica at 2.20 g/cm³. A service life of ≥50 cycles is standard under normal ash determination conditions.
Square Quartz Crucible for Rare Earth Oxide Thermal Processing
Key Advantages
- SiO₂ is inert to La₂O₃, CeO₂, Nd₂O₃ at ≤1200 °C.
- No alumina-rare earth mixed-oxide contamination is introduced.
- Square geometry is stable on horizontal tube furnace support rails.
TOQUARTZ® solution
Alumina crucibles react with rare earth oxides above 1100 °C. Mixed-oxide phases are introduced into the calcined product as a result. TOQUARTZ® square quartz crucibles remain chemically inert to La₂O₃, CeO₂, and Nd₂O₃ at standard processing temperatures. Product purity is maintained without switching to platinum or other high-cost alternatives.
Customization Services for TOQUARTZ® Square Quartz Crucibles
Dimensional Customization
- Custom diameters, height and wall thickness
- Special height-to-diameter ratios
- Specialized shapes beyond standard offerings
Material Modifications
- Grade selection (JGS-1, JGS-2, JGS-3)
- Specific OH content requirements
- Controlled impurity levels for specialized applications
- UV or IR transmission optimization
Special Features
- Added spouts or pouring lips
- Custom lids or covers
- Surface treatments (polishing, etching)
- Specialized markings or graduations
Material Specification Note
When requesting custom square quartz crucibles, please specify your material requirements. TOQUARTZ offers JGS-1, JGS-2, and JGS-3 grade quartz with varying spectral transmission characteristics. For applications with specific wavelength requirements, please include this information in your inquiry for optimal material selection.
TOQUARTZ® Customization Process
Submit your technical requirements or drawings. Our engineers will review and provide feedback on feasibility.
Receive detailed design specifications and pricing within 48 hours for your approval.
After approval, manufacturing begins with rigorous quality control. Typical custom orders ship within 7-14 days.
Usage Guidelines for Transparent Quartz Crucibles
Handling and Storage
- Handle with clean gloves to prevent fingerprint contamination
- Store in clean, dust-free environment
- Avoid direct contact with abrasive surfaces
- Use dedicated storage containers for unused crucibles
- Keep separated from other labware to prevent scratches
Chemical Compatibility
- Compatible with most acids except hydrofluoric acid
- Avoid hot phosphoric acid which can cause erosion
- Alkali metals and their oxides can react at high temperatures
- Rinse thoroughly after use with corrosive materials
- Prevent cross-contamination by dedicated use per application
Temperature Control
- Avoid rapid temperature changes exceeding 200°C/minute
- Pre-heat large crucibles gradually to prevent thermal shock
- Do not exceed maximum operating temperature (1100°C)
- Allow to cool naturally after high-temperature use
- Use appropriate thermal insulation for temperature stability
Cleaning & Maintenance
- Clean with dilute acids followed by deionized water rinse
- For organic residues, use acetone followed by alcohol rinse
- Avoid abrasive cleaning materials that can scratch surface
- Air dry or use clean, low-lint tissues
- Inspect regularly for cracks or damage before reuse
Need Technical Consultation?
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Why Partner with TOQUARTZ
Direct Factory Advantage
As a direct manufacturer, we can cut out the numerous intermediate links.
Engineering Expertise
Technical team guides clients from material selection to design optimization, translating specs into deliverables.
Flexible Manufacturing
Handling standard & custom orders via small-batch expertise and prototyping rigor to meet urgent deadlines.
Quality
Assurance
Pre-shipment 3-step validation:
1. dimensional accuracy,
2. material purity ,
3. performance thresholds
Global Supply Chain
Reliable global logistics to industrial hubs (DE/US/JP/KR priority) with trackable milestones.
Releted Products
As a specialized manufacturer with direct factory capabilities, TOQUARTZ provides both standard and custom quartz solutions with engineering support throughout the specification and implementation process.
FAQ
Q: How many thermal cycles can a square quartz crucible sustain in daily ash analysis at 815 °C?
A: A TOQUARTZ® square quartz crucible is rated for ≥50 thermal cycles under standard ash determination conditions. Dense arc-fused silica at 2.20 g/cm³ is used in fabrication, which directly extends cycle life over slip-cast alternatives. Porcelain crucibles used in comparable service typically fail within 5–10 cycles.
Q: Does iron contamination from a square quartz crucible affect NCM or LCO cathode performance?
A: Fe content in TOQUARTZ® square quartz crucibles is maintained below 2 ppm per batch. At this level, no measurable Fe leaching into the cathode lattice is detected under standard calcination conditions at 800–1000 °C. Total trace metals are held below 20 ppm and are certified on the batch COA supplied with every shipment.
Q: Is a square quartz crucible suitable for use in H₂ atmosphere sintering below 1000 °C?
A: A square quartz crucible is compatible with dry H₂ atmospheres at temperatures up to 1000 °C. Above this threshold, partial reduction of SiO₂ to SiO begins, causing surface whitening and gradual material loss. For H₂ sintering above 1000 °C, an engineering review is recommended before selection.
Q: Will a square quartz crucible react with rare earth oxides such as Nd₂O₃ or La₂O₃ at 1100 °C?
A: Fused silica is chemically inert to La₂O₃, CeO₂, Nd₂O₃, and Y₂O₃ at temperatures up to 1200 °C. No mixed-oxide phase formation is introduced into the processed material under these conditions. Alumina crucibles, by contrast, react with several rare earth oxides above 1100 °C and are not suitable for this application.
Q: How does the square geometry of a quartz crucible improve thermal uniformity compared to round crucibles?
A: The flat base of a square quartz crucible maintains full contact with the furnace shelf or support surface. This eliminates the rocking instability seen with round crucibles on flat support rails in horizontal tube furnaces. Consistent base contact produces more uniform heat transfer from the furnace element to the crucible bottom.
Contact our engineering team for technical consultation and pricing. We’ll help you select the optimal specifications for your application requirements.