Potassium cryolite — also known as potassium tetrafluoroaluminate, potassium fluoroaluminate, or Kalium Aluminium Fluorid — is a fluoride-based inorganic salt with molecular formula KAlF₄ / K₃AlF₆ and molecular weight of 258.24 g/mol. It belongs to the same fluoroaluminate family as sodium cryolite (Na₃AlF₆) but offers a lower melting point of 840°C, making it the preferred flux choice in applications where processing temperature control is critical.
With a density of 2.875–2.88 g/cm³ and a tightly controlled elemental composition — fluorine 48–53%, aluminum 17–19%, potassium 28–33%, iron max 0.15%, moisture max 1.5% — potassium cryolite delivers consistent performance across aluminum brazing, abrasive manufacturing, glass, and ceramics production.
As a potassium cryolite supplier based in China, Shenyang Yftdss Trading Co., Ltd. exports KAlF₄ in powder and crystal form to buyers in metallurgy, non-ferrous metals smelting, glass, ceramics, and welding industries worldwide.
| Product Name | Potassium Cryolite, Potassium Tetrafluoraluminate, Potassium fluoroaluminate, Kalium Aluminium Fluorid |
| Molecular formula | Na₃AlF₆, KAlF, KAlF₄ |
| Molecular weight | 258.24 g/mol |
| Color | White or light grey |
| Appearance | Powder or crystal |
| Melting Point | 840℃ |
| CAS No. | 13775-52-5 |
| EINECS No. | 237-409-0 |
| Density | 2.875~2.88 g/cm³ |
| Specification | F 48-53%, Al 17-19%, Fe 0.15% max, K 28-33%, H₂O 1.5% max |
| Package | In 25 kg or 1000 kg woven bag |
Application
Aluminum Smelting & Brazing — Flux
Potassium cryolite is widely used as a flux in aluminum smelting and aluminum brazing processes. Its lower melting point compared to sodium cryolite (840°C vs 1000–1025°C) makes it particularly suited to controlled-atmosphere brazing of aluminum heat exchangers, automotive components, and HVAC systems. It removes the oxide layer from aluminum surfaces during heating, enabling clean, strong metallurgical bonds without the need for corrosive post-braze cleaning.
Welding & Soldering — Flux Agent
In welding and soldering applications, potassium cryolite acts as an active flux, breaking down surface oxides on base metals and filler materials to promote better wetting, adhesion, and joint cleanliness. It is used in flux-cored wire formulations, welding rod coatings, and specialty soldering pastes where fluoride-based chemistry is required for difficult-to-join metals.
Abrasive Manufacturing — Active Filler
In bonded and coated abrasive products — grinding wheels, flap discs, and abrasive belts — potassium cryolite serves as an active filler that reduces grinding heat, extends abrasive life, and improves cut rate on ferrous and non-ferrous workpieces. Its controlled particle size and low moisture content (max 1.5%) ensure consistent blending and bonding in abrasive manufacturing processes.
Glass & Ceramics Industry — Melting Modifier
In glass and ceramics production, potassium cryolite improves melt fluidity, lowers processing temperature, and contributes to opacity and surface finish in specialty glass and ceramic glaze formulations. It is used in opalescent glass batches and ceramic frit production where fluoride-based fluxing action is required.
Potassium Cryolite — also known as Potassium Fluoaluminate, Potassium Hexafluoroaluminate, Potassium Aluminum Fluoride, or K3AlF6, CAS 13775-52-5 — serves two distinct downstream industries, and the grade you need depends on which one you're buying for.
Flux & Metallurgical Applications
Aluminum electrolytic smelting: used as a flux additive in fused-salt electrolysis to help lower the melting point of alumina and improve process efficiency, alongside or as a partial substitute for standard cryolite
Aluminum alloy casting: functions as a deoxidizing and degassing flux during melting, helping remove impurities and improve casting quality
Brazing & welding flux: a key component in flux coatings for aluminum, aluminum alloy, and stainless steel brazing and welding rods
Ferrous alloy production: used in the production of ferroalloys and effervescing (rimmed) steel
Refractory, Abrasive & Ceramics Applications
Abrasive wheels: active filler in resin-bonded and rubber-bonded abrasive wheels, improving wear resistance for metal grinding and surface treatment
Refractory formulations: used as a fluxing/bonding component within refractory material formulations rather than as a standalone refractory — its role here is to lower sintering temperature and improve bonding, not to withstand high service temperatures on its own
Glass & enamel manufacturing: acts as a flux and opacifier, lowering melting temperature and promoting the opalescent effect in opal glass and enamel coatings
Ceramics: improves hardness and surface durability in select ceramic formulations
Friction materials: used as a filler component in some friction material (brake pad) formulations
Because flux-grade and abrasive/refractory-grade buyers care about different properties (flux buyers prioritize melting behavior and purity; abrasive/refractory buyers prioritize particle size consistency), tell us which application you're sourcing for and we'll confirm the right specification before quoting.
Standard packaging:
25 kg PP woven bags with moisture-resistant PE inner liners.
Optional packaging:
50 kg lined bags or 1000 kg jumbo bags are available upon request.
Minimum order quantity:
1 metric ton, equivalent to 40 × 25 kg bags.
Small samples can be provided for laboratory evaluation and production qualification before a commercial order.
Storage
Store in a dry, cool and well-ventilated warehouse. Keep the bags tightly sealed and protect the material from moisture, acids and incompatible chemicals.
What is the difference between potassium cryolite and sodium cryolite?
The primary differences are the cation (potassium vs sodium), melting point, and application profile. Potassium cryolite melts at 840°C versus 1000–1025°C for sodium cryolite, making it the preferred flux for lower-temperature aluminum brazing and controlled-atmosphere processes. Sodium cryolite is primarily used in high-temperature aluminum electrolysis (Hall-Héroult process). If you are unsure which grade suits your application, contact us with your process temperature and substrate details.
What purity and particle size grades are available?
Our standard specification is F 48–53%, Al 17–19%, K 28–33%, Fe max 0.15%, H₂O max 1.5%. Custom particle size ranges for specific abrasive or brazing applications can be discussed. Provide your technical datasheet or process requirement during inquiry and we will confirm available options.
What is the minimum order quantity?
MOQ varies by destination and packaging format. We accept trial orders for qualification alongside full container loads for regular supply. Contact us with your target volume and shipping destination for a specific pricing and freight proposal.
Is potassium cryolite classified as hazardous for shipping?
Potassium cryolite contains fluoride compounds and requires appropriate handling and labeling for international transport. We provide full MSDS and shipping documentation compliant with IMDG and IATA regulations. Contact us with your destination port and we will advise on applicable transport classifications and documentation requirements.
Can you provide samples for laboratory testing?
Yes. Sample quantities are available for product qualification prior to order placement. Contact us with your application details and required sample quantity.
What documentation is available before order confirmation?
We provide COA, MSDS, and product technical data sheet on request prior to order. Certificate of Origin and full export documentation are provided with each shipment.
Do you supply sodium cryolite or other fluoride-based products?
Yes, we supply sodium cryolite (Na₃AlF₆, CAS 13775-53-6) alongside potassium cryolite. Our broader inorganic salts range includes Magnesium Chloride, Calcium Chloride, Potassium Chloride, Sodium Bicarbonate, Soda Ash, and Sodium Sulfate. Combined shipments can be arranged to reduce freight cost per unit.
ONLINE INQUIRY
We welcome you to specify your requirements in the enquiry form or other channels. Based on your needs, we will recommend the most suitable products, provide technical assistance, and engage in depth-in discussions, both commercially and technically.
Contact Us
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+86 187 4165 1985
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No.1-26-7, No.73, Xinggong North Street, Tiexi District, Shenyang City, Liaoning Province, China
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