Wood is mostly cellulose, hemicellulose and lignin. Paper and pulp production keeps the cellulose fibre; the lignin is the main by-product. In sulfite pulping it is dissolved as lignosulfonate, and recovering that liquor makes it a raw material for many industries. This page lists the main uses and where to find technical detail for each.
Why lignosulfonate is useful
Lignosulfonate is a water-soluble, negatively charged polymer. It sticks to particle surfaces and keeps them apart (dispersing), and when it dries it holds particles together (binding). Most of its uses come from one of these two effects.
Main uses
| Industry | Role | Technical detail |
|---|---|---|
| Concrete and gypsum | Water reducer and set retarder | Concrete admixtures |
| Unpaved roads and mining | Dust suppressant and soil binder | Dust suppression |
| Animal feed | Pellet binder | Feed pellet binding |
| Agriculture | Fertiliser binder, dispersant and micronutrient carrier | Lignosulfonate in fertilisers |
| Ceramics and refractories | Body binder and slip dispersant | Ceramics |
| Oil and gas | Drilling-mud thinner | Drilling fluids |
| Lead-acid batteries | Negative-plate expander | Battery expanders |
| Carbon black, coal and briquettes | Granulation binder, slurry dispersant | Carbon black |
| Dyes and pesticides | Dispersant for solid formulations | Pesticide formulations |
Environmental notes
Using lignosulfonate gives a use to a pulp-mill side stream, and its SDS describes it as not classified as hazardous and expected to be inherently biodegradable. Whether a particular use lowers the environmental impact of the final product depends on what it replaces and has not been measured by an LCA. See environmental and safety data.
Frequently Asked Questions
What is lignosulfonate made from?
It is made from lignin recovered from the spent liquor of sulfite wood pulping, the process that separates cellulose fibre for paper and pulp.
What are the main uses of lignosulfonate?
Concrete water reducers, dust control, feed pellet binding, fertiliser binding and dispersing, ceramics, drilling muds, lead-acid battery expanders and carbon black granulation.
Why is lignosulfonate called a by-product?
Pulp and paper production keeps the cellulose fibre. Lignin is removed in the process, and in sulfite pulping it leaves the mill dissolved in the liquor as lignosulfonate.