Home > Products > Alumina > High-purity Alumina

High-purity Alumina

High-Purity Alumina (HPA) Technical and Procurement Specification

Product Overview: High-purity alumina is an Al2O3 ceramic material engineered for precision applications where conventional industrial alumina cannot provide adequate control over metallic impurities, particle characteristics, phase composition, or thermal behavior.
Chemical Name: Aluminum Oxide
Formula: Al2O3
CAS No.: 1344-28-1
Material Type: High-purity inorganic ceramic powder
Common Purity Grades: 99.9%, 99.99%, 99.999% and higher (subject to specific technical requirements).

Alumina for Thermal Conductive Filler

Alumina for Thermal Conductivity Fillers (Al₂O₃) is an inorganic powder dominated by α-phase crystal form, featuring high purity, high thermal conductivity and electrical insulation. It has a

Add to Inquiry
Alumina Powder for Lithium Battery Separators

Alumina for Lithium-Ion Battery Separators is a high-performance alumina powder produced through specialized processing techniques according to the performance requirements of batteries and battery

Add to Inquiry
Nano Alumina

Nano-alumina is a high-purity ultrafine alumina powder with a particle size ranging from 1 to 100 nm, mainly existing in γ-alumina or α-alumina crystal form. It is a nano-scale inorganic functional

Add to Inquiry

HPA Selection Factors

Selection Factor	Core Focus & Impact Mechanism
Al2O3 Purity	Determines the overall purity level of the material.
Na2O / Sodium Content	Critical in applications where alkali contamination affects ceramic or crystal-growth processes.
Fe2O3 Content	Directly influences color, optical properties, and contamination control.
SiO2 Content	Influences sintering behavior and material purity.
CaO / MgO Content	Used to control trace-level contamination.
Particle Size Distribution (PSD)	Affects powder packing, dispersion, forming, and sintering performance (covers D10, D50, D90 ranges).
Specific Surface Area (BET/SSA)	Influences reactivity, sintering behavior, and powder processing.
Crystal Phase	Alpha-Al2O3 and transition alumina behave differently during processing.
Moisture & Loss on Ignition (LOI)	Relevant to storage, weighing, mixing, and thermal processing.
Bulk & Tap Density	Used for powder handling and formulation control.
Particle Morphology	Affects flowability, packing density, and dispersion.

Typical Application Areas

Sapphire and Crystal Growth: Utilized as feedstock for crystal growth, requiring strict control over alkali and transition-metal impurities.

Advanced Technical Ceramics: Applied in electrical insulators, ceramic tubes, wear-resistant components, furnace parts, and structural ceramic formulations.

Electronic Ceramics: Suitable for electronic and electrical components requiring precise chemical composition and predictable sintering behavior.

Optical and Functional Materials: Deployed in specialty optical formulations with strict limits on trace elements such as iron, silicon, sodium, calcium, and magnesium.

High-Temperature Materials: Leverages high-melting points, thermal stability, and chemical inertness for specialized refractory and furnace-lining requirements.

Ordering Technical Specifications

Chemical Specifications

Must define maximum threshold limits for Al2O3, Na2O, Fe2O3, SiO2, CaO, MgO, other relevant trace elements, moisture, and LOI.

Physical Specifications

Must specify D10, D50, D90, specific surface area, particle morphology, bulk density, tap density, agglomeration state, and crystal phase.

Packaging Specifications

Must select appropriate contamination-control measures including sealed inner bags, moisture-resistant packaging, clean external packaging, net weight per bag, lot identification, and production date.

Alumina Powder For Lithium Battery Separators suppliers

Procurement Quality Control Checklist

Chemical Purity Verification: Confirm that the impurity profile aligns completely with the process specification.

Physical Property Evaluation: Ensure the particle-size distribution suits the mixing, forming, coating, or sintering process.

Crystal Phase Verification: Confirm the supplied material is the specified alpha-phase or transition alumina.

Batch Consistency: Evaluate whether consecutive production lots remain stable within the agreed standard.

Test Method Alignment

Ensure analytical test methods are consistent between supplier and customer.

Lot Traceability

Ensure each shipment links back to a specific production lot and its corresponding Certificate of Analysis (COA).

Sample Validation

Pass representative sample evaluations before committing to bulk volume orders.

Supply Continuity

Assess the supplier's capacity for long-term, stable repeat fulfillment.

Frequently Asked Questions

Q: What is High-Purity Alumina (HPA)?

A: High-purity alumina is an inorganic ceramic powder primarily composed of Al2O3 with tightly controlled impurity levels. It is selected when conventional industrial alumina fails to meet strict chemical or physical requirements.

Q: What purity grades are commonly available?

A: Standard commercial purity grades include 99.9%, 99.99%, and 99.999% or higher, with detailed impurity limits tailored to specific production processes.

Q: Why do materials with the same nominal purity perform differently in application?

A: Even if two powders share a 99.99% nominal purity rating, variations in trace impurity profiles (such as Na2O or Fe2O3), particle size distribution (PSD), specific surface area (BET), agglomeration state, or thermal history can cause distinct behaviors during sintering or crystal growth.

Q: Is high-purity alumina the same as alpha-alumina?

A: No. Purity describes the chemical composition cleanliness, whereas alpha-Al2O3 describes the crystal structure phase. HPA can be specified alongside a required crystal phase based on processing needs.

Q: Which key impurities should be monitored during procurement?

A: Commonly controlled impurities include sodium (Na2O), iron (Fe2O3), silicon (SiO2), calcium (CaO), magnesium (MgO), and other trace elements sensitive to the end application.

Q: How should the appropriate particle size distribution (PSD) be chosen?

A: Particle size selection depends entirely on the specific mixing, forming, tape-casting, coating, or sintering process. Buyers should evaluate target D10, D50, and D90 parameters against their internal process window.

Q: Is sample validation necessary before bulk purchasing?

A: Yes. For applications with strict purity and physical-material demands, evaluating representative production samples prior to volume ordering is strongly recommended to ensure technical alignment.

With abundant experience, we are one of the most professional high-purity alumina manufacturers and suppliers in China. Please feel free to buy high quality high-purity alumina for sale here and get quotation from our factory. For price consultation, contact us.

High thermal conductivity alumina filler, high purity alumina, Nano Alumina