Sodium Thioglycolate CAS 367-51-1

Sodium Thioglycolate – Versatile Chelating and Flotation Agent for Mining, Water Treatment, and Corrosion Inhibition

Basic Information

• CAS Number: 367-51-1

• Molecular Formula: C₂H₃NaO₂S (NaSCH₂COO)

• Molecular Weight: 114.10 g/mol

• Synonyms: Sodium mercaptoacetate, Thioglycolic acid sodium salt

• Appearance: White crystalline powder (hygroscopic)

• Solubility: >500 g/L in water

• pH (10% solution): ~11.0

• Melting Point: ~150°C (decomposes)

• Storage: Store in tightly sealed containers, protected from moisture and light

Overview
Sodium thioglycolate is the sodium salt of thioglycolic acid, a powerful chelating agent with strong affinity for copper (Cu(I/II)) and iron (Fe(III)) ions. Its excellent water solubility and moderate alkalinity make it a practical industrial alternative to thioglycolic acid (TGA) in various applications, including mineral flotation, wastewater treatment, and corrosion inhibition. It is widely used in mining, chemical processing, and environmental remediation.

Key Applications

• Copper ore flotation: Used as a selective depressant for pyrite in copper flotation circuits, improving copper recovery by 8–12% at typical dosages of 50–200 g per ton of ore (pH ~11.5).

• Wastewater treatment: Acts as a complexing agent for precipitating heavy metals (Cu, Fe, Hg, Pb) from industrial effluents, facilitating their removal.

• Corrosion inhibition: Provides effective protection of steel in acidic environments; at 0.1% concentration in 1 M HCl, reduces steel mass loss by up to 85% (23°C, 2 hours) through Langmuir adsorption (ΔG_ads = –28 kJ/mol).

• Industrial cleaning: Used as a mild stripping agent for metal surfaces and as a chelator in various formulations.

• Nanotechnology: Employed as a mild reducing agent for the synthesis of gold nanoparticles (AuNPs) with controlled size (10–20 nm) from Au³⁺ precursors.

Key Benefits

• Powerful chelation of Cu(I/II), Fe(III), and other heavy metals.

• High water solubility – easy to handle and dose.

• Selective action in flotation processes – improves metal recovery.

• Effective corrosion inhibition in acidic media.

• Versatile – applicable in mining, water treatment, chemical synthesis, and nanomaterials.

• Moderately biodegradable (BOD₅/COD ≈ 0.3).

Safety and Handling

• Oral LD₅₀ (rat): >2000 mg/kg – low acute toxicity.

• May cause skin and eye irritation; use appropriate personal protective equipment (gloves, safety goggles) when handling.

• Hygroscopic – protect from moisture to prevent caking.

• Store in a cool, dry place, away from strong oxidizers and acids.

• Shelf life: typically 24 months under recommended storage conditions.

Quality Assurance
Each batch is tested for purity, water content, and chelating performance to ensure consistent quality.