What is Alumina Trihydrate (ATH)? Properties, Uses & Benefits

Alumina Trihydrate (ATH), also known as Aluminum Hydroxide (Al(OH)₃)  or hydrated alumina, is a white, odorless, non-toxic, and chemically stable powder derived from bauxite through the Bayer process. As one of the most widely used inorganic flame retardants and functional fillers, ATH plays a crucial role in various industries including plastics, rubber, coatings, wire and cable, artificial marble, ceramics, and pharmaceuticals.

Chemical Properties of Alumina Trihydrate

• Chemical Formula: Al(OH)₃
• CAS Number: 21645-51-2
• Molecular Weight: 78.00 g/mol
• Appearance: Fine white powder or crystalline form
• Solubility: Insoluble in water and organic solvents, soluble in acids and alkalis
• Decomposition Temperature: ~ 300°C (releases water vapor and forms Al₂O₃)

How is Alumina Trihydrate Production Method?

Alumina Trihydrate is mainly produced via the Bayer Process, which involves extracting alumina from bauxite ore. The aluminum hydroxide is then precipitated from the sodium aluminate solution and carefully controlled to produce ATH with specific particle sizes and purity levels.

Key Benefits of Alumina Trihydrate

• Environmentally friendly, halogen-free flame retardant
• Non-toxic and thermally stable
• High whiteness and opacity as a filler
• Cost-effective replacement for other flame retardants
• Available in customizable particle sizes (1μm – 20μm D50)

Applications: What is Alumina Trihydrate Used For?

Alumina trihydrate is widely used across various industries due to its multifunctionality:

1. Flame Retardant

ATH is widely used as an eco-friendly, non-halogenated flame retardant in:

• Wire and cable insulation (EVA, PE, PVC)
• Rubber sheets and conveyor belts
• Automotive interior plastics
• Electrical enclosures and housings

2. Functional Filler

Due to its cost-effectiveness and multifunctionality, ATH is used as a filler in:

• Paper and coating industries
• Synthetic marble and solid surface materials
• Adhesives, sealants, and construction compounds

3. Chemical Intermediary

• Used to produce high-purity alumina (Al₂O₃) via thermal decomposition
• Acts as a raw material for aluminum-based chemicals such as aluminum sulfate and polyaluminum chloride

4. Pharmaceutical Industry

Helps to neutralize excess gastric acid and relieve symptoms like heartburn or indigestion

Serves as an antacid in over-the-counter medications

Typical Technical Specifications

High whiteness aluminum hydroxide for filler (Seeding process)
It is produced by precipitaion method with the sodium aluminate solution from sintering process as the seeds, its characteristics – Slow decomposition rate, complete crystallization, low impurity, high intensity and good transparency.
It has the texture properties of jade, which can be used as superior filler in the solid surface, crafts and other composites.

Brand	Chemical composition（%）					DOP	Whiteness	Particle size		Moisture
	Al(OH)3≥	SiO2≤	Fe2O3≤	Na2O≤	Na2O (S)≤	ml/100g≤	%≥	D50μm	+325mesh≤	%≤
H-WF-14SP	99.6	0.03	0.02	0.20	0.02	30	95	16±3	12	0.3
H-WF-25SP	99.6	0.03	0.02	0.20	0.	30	94	25±5	–	0.2
H-WF-25MSP	99.6	0.03	0.02	0.20	0.03	21	95	–	–	0.2
H-WF-50SP	99.6	0.03	0.02	0.20	0.02	30	93	50±10	–	0.2
H-WF-75SP	99.6	0.03	0.02	0.20	0.02	30	92	85±15	–	0.1
H-WF-90SP	99.6	0.03	0.02	0.20	0.02	30	91	95±20	–	0.1

High whiteness aluminum hydroxide for filler (Carbonating process)
High whiteness(Reputated as China White), low oil absorption, good stability at room temperature  and dehydrated to alumina while heating, to make the products have the function of flame retardant. Its a good flame retardant filler because that no toxic and corrosive gases were generated in thermal decomposition.It’s widely used in the solid surface, mould plastics, epoxy potting compound and other composite materials.

Brand	Chemical composition（%）					DOP	Whiteness	Particle size		Moisture
	Al(OH)3≥	SiO2≤	Fe2O3≤	Na2O≤	Na2O(s)≤	ml/100g≤	%≥	D50μm	+325mesh≤	%≤
H-WF-8	99.6	0.05	0.02	0.30	0.03	33	96	8±2	3	0.4
H-WF-10	99.6	0.05	0.02	0.30	0.03	33	96	10±2	4	0.3
H-WF-14G	99.6	0.05	0.02	0.30	–	30	90	11±3	–	0.3
H-WF-14LV	99.6	0.05	0.02	0.30	0.03	29	95	13±3	15	0.3
H-WF-14	99.6	0.05	0.02	0.30	0.03	32	95	15±3	15	0.3
H-WF-15A	99.6	0.04	0.01	0.20	0.03	32	98	13±2	–	0.3
H-WF-25	99.6	0.05	0.02	0.30	0.03	32	95	25±5	–	0.2
H-WF-75	99.6	0.05	0.02	0.25	0.03	40	93	85±15	–	0.1
H-WF-90	99.6	0.05	0.02	0.25	0.02	40	93	100±20	–	0.1
H-WF-100	99.6	0.1	0.02	0.30	–	40	90	≥90	–	0.1

Why Choose Alumina Trihydrate from Banlanchem?

As a professional alumina trihydrate manufacturer and supplier from China, Banlanchem provides high-purity ATH powders tailored to your application. We offer:

• Strict quality control (ISO-certified)
• Customizable particle size and surface treatment
• Fast delivery and technical support

Environmental and Safety Profile

• Non-toxic
• Non-corrosive
• No hazardous by-products
• Compliant with RoHS and REACH regulations
• Low smoke and zero halogen (LSZH) performance in cable applications

Related Questions About Alumina Trihydrate

• Q: What is the difference between ATH and aluminum oxide?
  A: ATH is Al(OH)₃, while aluminum oxide (Al₂O₃) is the product of thermal decomposition of ATH.
• Q: Is ATH safe?
  A: Yes, ATH is non-toxic, non-corrosive, and compliant with RoHS, REACH, and halogen-free regulations.
• Q: What is alumina trihydrate used for?
  ATH is used as a flame retardant, filler, and precursor to alumina.

External Resources

• Aluminum Hydroxide (Wikipedia)
• RoHS Directive on flame retardants
• Aluminum Hydroxide SDS

Conclusion

Now you understand what is alumina trihydrate and why it plays such a vital role in flame retardants, functional fillers, and pharmaceutical products. For industrial-grade ATH with consistent performance, contact alumina trihydrate supplier Banlanchem today to request a quote or sample.