Magnesium lignosulfonate dispersant grades keep solid particles separated and suspended in water. This page explains how it disperses, where it is used and how to test it in your system.
How It Disperses
The anionic polymer adsorbs on particle surfaces and gives them a negative charge. Particles repel each other, so the suspension stays fluid at higher solids and settles more slowly.
Where It Is Used
| System | Purpose |
|---|---|
| Pesticide wettable powders and suspensions | Dispersion and suspensibility when mixed with water |
| Dyes and carbon black | Keeps pigment particles apart |
| Cement raw-mix slurry | Lowers viscosity (deflocculant) |
| Drilling mud | Thinner |
| Ceramic slips | Fluidity at lower water |
How to Test
- Prepare the system without dispersant as a control.
- Add the dispersant at three or more levels.
- Measure viscosity, suspensibility or settling over time.
- Check storage and heat stability for formulations.
- Compare with your current dispersant at equal cost.
Grade Choice
- Grade One: low insolubles, pH 4 – 7; the usual starting point.
- Grade Two: alkaline (pH around 10).
- Liquid: for pumped dosing.
| Grade (code) | Form | Lignosulphonate (dry basis) | pH | Other key values |
|---|---|---|---|---|
| Grade One (GAC-MgLS-1) | Yellow-brown powder | 55% min | 4 – 7 | Total Mg + Ca 8% min; insolubles 1.0% max; reducing matter 7% min |
| Grade Two (GAC-MgLS-2) | Powder | 50% min | around 10 | Total Mg + Ca 5% min; insolubles 1.5% max |
| Liquid (GAC-MgLS-L) | Liquid, about 45% solids | 50% min | — | Insolubles 1% max; reducing sugar about 7% |
| Feed Grade (GAC-MgLS-Feed) | Light to dark brown powder | 55% min | 4.5 – 6.5 | Pb 10, As 3, Cd 1 mg/kg max; Salmonella negative in 25 g |
Dispersant technology across lignosulfonates: greenagrochem.net.
Compared With Synthetic Dispersants
Naphthalene sulfonate (NNO) and melamine-type dispersants are synthetic and can be stronger in specific systems, such as some dyes. Lignosulfonates are bio-based and usually lower in cost, and many formulators combine both. Compare at equal cost in your own formulation.
Packing and Storage
- Powder: 25 kg lined woven bags or 500 – 600 kg jumbo bags; 24 months unopened; keep dry and reseal opened bags.
- Liquid: flexitank, IBC or drums; 12 months; protect from freezing.
- Keep away from strong oxidizers, acids and bases (SDS).
Frequently Asked Questions
Is magnesium lignosulfonate a good dispersant?
It is an effective anionic dispersant in many water-based systems; test it against your current dispersant.
Which magnesium lignosulfonate grade is used as a dispersant?
Grade One is the usual starting point because of its low insolubles.
How much dispersant is needed?
Set the dose by trial, measuring viscosity or suspensibility at several levels.
Can magnesium lignosulfonate replace NNO?
Sometimes partly. Test blends and full replacement for dispersion, viscosity and stability.
Does it work in hard water?
Usually, but test with your water; high salt levels can affect performance.
