Scandium Sulfate Octahydrate, Scandium Sulfate Hydrate, Scandium Trisulfate Octahydrate, 52788‑54‑2

Scandium Sulfate Octahydrate, Scandium Sulfate Hydrate, Scandium Trisulfate Octahydrate, 52788‑54‑2

SCANDIUM(III) SULFATE OCTAHYDRATE 

Chemical Name: Scandium(III) Sulfate Octahydrate / Scandium Trisulfate Octahydrate
CAS Number: 52788-54-2
EC Number: 256-050-7
HS Code: 283429

1. PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY

2. CHEMICAL STRUCTURE AND EXPLANATION

Chemical Structure and Bonding:

Scandium(III) Sulfate Octahydrate is an ionic compound composed of two Scandium (Sc³⁺) cations and three Sulfate (SO₄²⁻) anions. Scandium is in the +3 oxidation state (trivalent) in this compound. The molecule contains eight molecules of water of crystallization (8H₂O).

Molecular Formula Representation:

Sc₂(SO₄)₃·8H₂O

This formula indicates the following structure:

• 2 Scandium ions (Sc³⁺): Central metal atoms.

• 3 Sulfate groups (SO₄²⁻): Tetrahedral anions.

• 8 Water molecules (H₂O): Water of crystallization bound to the crystal lattice.

Crystal Structure and Ionic Arrangement:

In the crystal structure, each Sc³⁺ ion is coordinated by oxygen atoms (both from sulfate groups and water molecules). Sulfate ions and water molecules act as bridges between scandium centers. The eight water molecules are part of the crystal structure and impart specific thermal stability and solubility characteristics to the compound. Upon heating, these water molecules are sequentially removed (dehydration), eventually forming the anhydrous form.

Simplified Ionic Representation:

        Sc³⁺   SO₄²⁻   H₂O
          \     /       /
           Sc₂(SO₄)₃ · 8H₂O
          /     \       \
        SO₄²⁻  SO₄²⁻  H₂O

(An ionic crystal lattice composed of 2 Sc³⁺ ions, 3 SO₄²⁻ ions, and 8 water molecules)

Structural Properties:

Dehydration (Loss of Water upon Heating):

Scandium Sulfate Octahydrate loses water sequentially when heated:

Sc₂(SO₄)₃·8H₂O → Sc₂(SO₄)₃·xH₂O → Sc₂(SO₄)₃ (anhydrous)

Different hydrate forms (e.g., pentahydrate, monohydrate) may form as intermediates depending on the temperature.

3. PHYSICAL AND CHEMICAL PROPERTIES

Important Physical Notes:

• Scandium Sulfate Octahydrate is hygroscopic and absorbs moisture from the air. This requires special packaging and storage conditions.

• When dissolved in water, the solution becomes acidic due to the hydrolysis of Sc³⁺ ions.

• Upon heating, it first loses water of crystallization; at higher temperatures, the sulfate groups decompose to form scandium oxide (Sc₂O₃).

• High purity grades (≥ 99%) are available in rare earth element purity.

4. CHEMICAL PROPERTIES AND REACTIONS

Important Reactions:

1. Thermal Decomposition:

This reaction is the primary method used for producing scandium oxide.

First, dehydration:
Sc₂(SO₄)₃·8H₂O → Sc₂(SO₄)₃ + 8H₂O (approximately 100-250°C)

Then, thermal decomposition:
Sc₂(SO₄)₃ → Sc₂O₃ + 3 SO₃ (high temperature, >600°C)

2. Reaction with Bases (Precipitation):

Scandium hydroxide precipitates, which can be used as an intermediate in scandium oxide production.

Sc₂(SO₄)₃ + 6 NaOH → 2 Sc(OH)₃ ↓ + 3 Na₂SO₄

3. Dissolution and Hydrolysis in Water:

Hydrolysis of scandium ions causes the solution to become acidic.

Sc³⁺ + H₂O ⇌ Sc(OH)²⁺ + H⁺

4. Precipitation with Ammonia:

Sc₂(SO₄)₃ + 6 NH₃ + 6 H₂O → 2 Sc(OH)₃ ↓ + 3 (NH₄)₂SO₄

5. APPLICATIONS AND INDUSTRIAL USES

5.1. Aerospace and High-Performance Alloys (Most Important Application)

Scandium Sulfate is a precursor material used in the production of Aluminum-Scandium (Al-Sc) alloys. These alloys are critical in the aerospace and defense industries. Al-Sc alloys offer low density, high strength, excellent corrosion resistance, and superior weldability.

5.2. Optics and Specialty Glass

5.3. Advanced Ceramics and Materials

5.4. Laboratory and Research

5.5. Electronics

6. SECTORAL SUITABILITY TABLE

7. SAFETY AND TOXICOLOGY

Safety Precautions:

• Keep away from heat, sparks, and open flames.

• Store separately from combustible materials.

• Avoid dust formation.

• Work in well-ventilated areas.

• Use protective gloves, safety goggles, and dust mask.

• Wash hands thoroughly after handling.

• In case of eye contact, rinse with plenty of water for at least 15 minutes and seek medical attention.

8. STORAGE AND HANDLING

9. TRANSPORT AND REGULATORY INFORMATION

10. QUALITY AND PURITY

11. RAW MATERIALS AND DOWNSTREAM PRODUCTS

11.1. Raw Materials (Upstream)

11.2. Downstream Products

12. FIRST AID MEASURES

13. FIREFIGHTING MEASURES

14. ACCIDENTAL RELEASE MEASURES

15. SUMMARY AND CRITICAL WARNINGS

SUMMARY:

Scandium(III) Sulfate Octahydrate (Sc₂(SO₄)₃·8H₂O, CAS 52788-54-2) is an inorganic salt composed of two Scandium (Sc³⁺) and three Sulfate (SO₄²⁻) ions, containing eight molecules of water of crystallization. It appears as a white crystalline solid, is highly soluble in water, and is hygroscopic (moisture-absorbing). Upon heating, it first loses water of crystallization; at higher temperatures, it thermally decomposes to form scandium oxide (Sc₂O₃) and sulfur oxides.

Its most critical application is as a precursor material in the production of Aluminum-Scandium (Al-Sc) alloys used in the aerospace and defense industries. It is also used in specialty glass, optical materials, advanced ceramics, as a catalyst, and as a laboratory reagent.

Under GHS classification, it is an oxidizer and harmful (H272, H302, H315, H319). Due to its oxidizing properties, it must be kept away from combustible and reducing materials. Due to its hygroscopic nature, it must be stored in a cool, dry environment in tightly closed packaging. Appropriate Personal Protective Equipment (PPE) must be used during handling to avoid inhalation of dust and contact with skin/eyes.

Key Properties:

CRITICAL WARNINGS:

1. Oxidizing Property: Exhibits moderate oxidizing properties. Contact with organic materials, reducing agents, and combustible materials must be avoided. May intensify fire (H272). Therefore, it must be stored separately and away from combustible materials.

2. Hydrated Structure and Thermal Instability: Contains eight molecules of water of crystallization. Upon heating, it sequentially loses water (dehydration). It decomposes at approximately 250°C and at higher temperatures (>600°C) releases toxic sulfur oxides (SO₂, SO₃). Thermal processes should be conducted in well-ventilated areas or under fume hoods.

3. Hygroscopic Property: This is the most significant physical drawback. Storage and weighing operations must not be performed in humid environments. After opening, the container must be quickly resealed and storage under an inert atmosphere (e.g., nitrogen) is preferred. Moisture absorption compromises weighing accuracy and chemical stoichiometry.

4. Structure and Purity: The chemical structure requires high purity (≥ 99.9%) for applications such as Al-Sc alloys and optical materials. Impurities from other rare earth elements (yttrium, lanthanides) directly affect the performance of end products.

5. Dust Control: The powder form can irritate the lungs if inhaled. Dust control measures must be implemented in the work area (closed systems, local exhaust ventilation) and appropriate respiratory protection (dust mask or N95/FFP2) must be used.

6. Aqueous Solution Acidity: Aqueous solutions are acidic due to hydrolysis. Appropriate protective equipment should be used when working with acidic solutions, and base solutions should be available for neutralization.

7. Environmental Precautions: As a water-soluble salt, release into the environment (particularly water sources) must be prevented. Waste solutions must not be discharged into sewers and must be disposed of according to local regulations.

8. Regulatory Compliance: Registration and notification requirements under REACH and KKDİK must be observed. It is classified as Class 5.1 (Oxidizing substance) under ADR/IMDG/IATA, requiring special labeling and documentation during transport. Use in food, cosmetics, and textile sectors is strictly prohibited.

9. Storage Warning: After opening the package, the remaining product should be immediately transferred to a moisture-proof container and sealed after purging with an inert gas (nitrogen, argon). It must be stored separately from combustible and reducing materials.

Disclaimer: This Technical Data Sheet (TDS) is for informational purposes only. The information provided is based on available data and is believed to be accurate. However, the user is solely responsible for determining the suitability of the product for their specific applications and for complying with all applicable regulations and safety requirements. For complete safety, handling, storage, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. Users are responsible for testing the product in their own processes and applications. All local, national, and international regulations must be followed when working with Scandium(III) Sulfate Octahydrate.