Magnesium lignosulfonate is a family of water-soluble, lignin-derived anionic materials—not one universal purity, molecular weight, pH or application grade. Buyers should compare the exact commercial code, TDS revision, shipment COA and end-use test rather than assembling a specification from unrelated online ranges.
Material identity and functional chemistry
Lignosulfonates are heterogeneous, polydisperse macromolecular mixtures formed when lignin is cleaved and sulfonated during sulfite pulping or when another technical lignin is subsequently sulfonated. Sulfonate, carboxyl, phenolic hydroxyl and other groups contribute to water solubility, adsorption and electrostatic/steric effects. Magnesium is the principal counter-ion designation, but the full inorganic and organic composition varies by feedstock, process and grade.
Therefore, a single molecular formula or molecular-weight number does not adequately identify a shipment. Functional selection should use measurable grade properties and application testing.
Current Green Agrochem industrial grade comparison
| Property | GAC-MgLS-1 Grade One, Rev. 1.0 |
GAC-MgLS-2 Grade Two, Rev. 1.0 |
GAC-MgLS-L Liquid, Rev. 1.0 |
|---|---|---|---|
| Appearance | Yellow-brown powder | Yellow-brown powder | Black liquid |
| pH | 4–7 | Around 10 | Not stated in current TDS |
| Dry matter / solids | 95% min | 95% min | Around 45% solids |
| Water-insoluble matter | 1.0% max | 1.5% max | 1.0% max |
| Total magnesium and calcium | 8% min | 5% min | Not stated in current TDS |
| Lignosulphonate content | 55% min | 50% min | 50% min |
| Sulphate | 2% min | 2% min | Not stated in current TDS |
| Total reducing matter / reducing sugar | 7% min | 7% max | Around 7% |
| Density | 0.55 g/cm³ | 0.55 g/cm³ | Not stated in current TDS |
| Moisture | 7% max | 7% max | Not applicable as a powder-moisture specification |
| Documented shelf life | 24 months, original unopened packaging | 24 months, original unopened packaging | 12 months under recommended storage conditions |
These TDS values are described as typical production results for reference and do not replace the contracted specification or signed lot COA. Several definitions and methods—especially pH basis, total magnesium/calcium basis, reducing-matter method and powder density method—should be confirmed before technical comparison or equipment design.
How to choose among the industrial grades
| Decision factor | Why it matters | Qualification action |
|---|---|---|
| pH window | Grade One and Grade Two have materially different stated pH | Test in the actual formulation; do not neutralize or substitute without compatibility evidence |
| Insolubles | Affect screens, nozzles, filters, surface defects and sediment | Use the customer’s dilution water and process filtration |
| Counter-ion/mineral contribution | May change electrolyte balance and interaction with binders, clays, cement or pigments | Confirm analytical basis and formulation tolerance |
| Reducing matter/sugars | Can influence cement setting, colour, biological stability or other processes | Define the correct method and application acceptance test |
| Powder versus liquid | Changes freight, dissolution, active-solids calculation, tank/pump design and storage | Compare delivered cost and performance on equal active solids |
Application qualification—not automatic performance
Industrial grades may be screened for dispersion, binding, selected cementitious systems, ceramics/mineral slurries and other aqueous formulations when supported by the grade documents and trials. The product name alone does not guarantee water reduction, strength, set behaviour, salt tolerance, corrosion performance, drilling-fluid rheology or binder strength.
- Define the control and measurable acceptance criteria.
- Compare candidate grades on both as-supplied and dry-active bases.
- Hold water, raw-material lots, pH, temperature, addition order, mixing and conditioning constant.
- Measure immediate response, storage/hold stability and the final end-use property.
- Confirm the selected grade in a controlled production trial and lock the specification/COA requirements.
Evidence status of former generic properties
| Former value or statement | Evidence/status | Correct interpretation |
|---|---|---|
| Molecular weight 1,000–140,000 Da | No exact grade, distribution method or current supplier document identified | Polydispersity is real, but this range is not a shipment specification |
| Water solubility ≥98.5% | Not present as an exact-grade result in the reviewed TDS | Use water-insoluble matter and the agreed dissolution/filtration test |
| pH 4.0–6.0 at 5–10% solution | Conflicts with the distinct Grade One and Grade Two TDS values | Use the exact-grade pH and confirm concentration/method |
| Reducing sugars 5–7%; sulphate 4–6%; chloride ≤0.5%; ash ≤12% | Composite values not supported together by one reviewed exact-grade TDS | Do not publish them as a standard magnesium-lignosulfonate specification |
| Clear solution, organic-solvent stability and moderate-salinity functionality | Broad qualitative claims without an exact test system | Test clarity, solvent/electrolyte compatibility and performance in the actual formulation |
Feed and agriculture boundaries
GAC-MgLS-Feed is a separate animal-feed grade with its own composition, microbial/heavy-metal controls and use requirements; it belongs to LigninChina’s animal-nutrition division and its data must not be mixed into this industrial comparison. Magnesium micronutrient and fertilizer intent belongs to ChinaLignin’s agriculture division.
Buyer document checklist
Request the exact product code and current TDS/SDS, a signed shipment COA, analytical methods, intended application, packaging and storage information. For samples and grade matching, contact info@greenagrochem.com. Continue to the magnesium lignosulfonate product route for industrial procurement.
