Magnesium lignosulfonate (CAS No. 8061-54-9) is a water-soluble anionic polyelectrolyte polymer derived from the sulfite pulping process of wood, primarily softwood. It is supplied as a yellow-brown powder (Grade One and Grade Two) or a black liquid, and is used across various industries due to its versatile properties.
Technical Specifications
- Product Name: Magnesium Lignosulfonate (Magnesium Lignosulphonate)
- Appearance: Yellow-brown powder (GAC-MgLS-1, GAC-MgLS-2); black liquid (GAC-MgLS-L)
- Solubility: Readily soluble in water; water-insoluble matter 1.0% max (Grade One), 1.5% max (Grade Two)
- Lignosulfonate Content: 55% min (Grade One), 50% min (Grade Two), dry basis
- Dry Matter: 95% min (powder grades)
- pH: 4–7 (Grade One); around 10 (Grade Two)
- Moisture Content: 5% max
- Total Magnesium & Calcium: 8% min (Grade One), 5% min (Grade Two)
- Total Reducing Matter: 7% min (Grade One), 7% max (Grade Two)
- Molecular Weight: Broad range, typically 1,000–140,000 Da (polydisperse; literature range for lignosulfonates, not a product specification)
- Chemical Formula: Not precisely defined due to its complex polymeric structure
- Main Components: Magnesium salt of lignosulfonic acid, containing sulfonated phenylpropane units
Grades, TDS and MSDS
| Grade | Key values (current TDS) | Documents |
|---|---|---|
| Grade One (GAC-MgLS-1) | Yellow-brown powder, pH 4–7, lignosulphonate 55% min | TDS · MSDS |
| Grade Two (GAC-MgLS-2) | Yellow-brown powder, pH around 10, lignosulphonate 50% min | TDS · MSDS |
| Liquid | Black liquid, around 45% solids, lignosulphonate 50% min | TDS · MSDS |
| Feed Grade | Pellet binder grade with heavy-metal and microbiological limits | TDS · MSDS |
Values are typical results from the current Green Agrochem TDS; each shipment carries a batch COA. For packing, samples and prices, contact LigninCorp. For what each value means and how the grades compare with calcium and sodium lignosulfonate, see the magnesium lignosulfonate reference on Lignosulfonate.com.
Production Process
Magnesium lignosulfonate is extracted from pulping liquor via purification, evaporation, chemical treatment, and drying. It is a byproduct of the sulfite pulping process, where wood chips are treated with magnesium-based sulfite or bisulfite salts (MgSO₃ or Mg(HSO₃)₂) under acidic conditions (pH 1–5). The process involves sulfonation and hydrolysis, introducing sulfonic acid groups to the lignin structure, enhancing its water solubility. The final product can be supplied as a powder or liquid (the liquid grade, GAC-MgLS-L, has around 45% solid content).
Key Properties
- Water Solubility: Highly soluble, making it effective as a dispersant and viscosity modifier.
- Anionic Polyelectrolyte: Contains sulfonic and carboxyl groups, contributing to its surfactant and dispersion capabilities.
- Binding and Dispersing: Acts as a binder for powdery/granular materials and a dispersant for insoluble solids/liquids in water.
- Plasticizing: Enhances workability in concrete and ceramics by reducing water content.
- Chelating: Can bind metal ions, useful in applications like wastewater treatment.
- Dust Suppression: Forms a high-viscosity, sticky layer when dried, effective for dust control on roads and industrial processes.
Applications
- Concrete Admixture:
- Ceramics and Refractory Materials:
- Oil and Gas Industry:
- Other Uses:
Chemical and Physical Characteristics
- Structure: Complex, amorphous polymer with phenylpropanoid units (primarily guaiacyl units). Sulfonation occurs on the side chains, not the aromatic rings, enhancing solubility.
- Vibrational Spectroscopy (literature values from characterisation studies of lignosulfonates, not product specifications):
- XPS Analysis (literature values, not product specifications):
- Stability: Stable at room temperature under normal storage conditions. Avoid strong bases, acids, and excessive heat.
Safety and Toxicological Data
- Hazards: Not classified as hazardous under normal industrial handling based on available data (GAC-MgLS MSDS, section 2). Fine powder may cause temporary mechanical irritation to eyes, skin, nose or throat.
- Health Effects:
- Eyes: May cause irritation; flush with water for at least 10 minutes.
- Skin: Non-poisonous but may cause irritation; wash with soap and water.
- Inhalation: No specific acute effects; remove to fresh air if irritation occurs.
- Ingestion: Seek medical attention or contact poison control.
- Environmental: No product-specific aquatic toxicity data are available; lignosulfonates are generally regarded as having low aquatic toxicity relative to synthetic dispersants. Mobile in soil because of high water solubility (MSDS, section 12).
Disposal and Handling
- Disposal: Dispose of in approved landfills or apply at recommended rates. Follow federal, state, and local regulations.
- Handling: Wear overalls, safety glasses, gloves, and a dust mask if excessive dust is present. Avoid generating dust and wash hands after use.
Additional Notes
- MSDS Availability: Material Safety Data Sheets are available from suppliers like Green Agrochem.
- Suppliers: Companies like Green Agrochem provide magnesium lignosulfonate in various forms. For pricing or samples, contact suppliers directly
- Research Applications: Used in studies for phenolic resin composites and as a bio-adhesive in particleboard manufacturing with low formaldehyde emissions.
