Lignosulfonate Industrial Binder
Lignosulfonates are water-soluble binders made from lignin. Dissolved in the mixing water, they wet fine particles and, as the product dries, hold the particles together. They are used to briquette coal, coke and charcoal fines, to agglomerate ore and metal powders, to bind foundry sand cores and to give ceramic and refractory bodies green strength. Calcium lignosulfonate is the grade most often used; sodium grades dissolve faster.
How a lignosulfonate binder works
- The binder is dissolved or dispersed in the mixing water and blended with the fines before pressing, pelletizing or forming.
- During pressing or forming, the solution fills the gaps between particles and gives the green product its handling strength.
- As water evaporates during drying, the lignosulfonate forms solid bridges between particles; dried strength is usually much higher than green strength.
- Because lignosulfonate stays water-soluble, dried products can soften if they get wet. Covered storage, a water-resistant additive or a combined binder system is used where this matters.
- At high temperature the organic binder burns out, so in fired products (pellets, cores, ceramics) other bonds take over after firing.
Where lignosulfonate binders are used
Coal, coke and charcoal briquettes
Fines from screening and handling are pressed into briquettes that can be stored, transported and used like lump fuel or reductant. For charcoal and biomass, lignosulfonate is used as an alternative or addition to starch or molasses.
What to test
- Green and dried strength (drop and crush)
- Water resistance
- Ash and sulfur added for the end use
Lignosulfonate as a briquette binder · Briquette binder: coal, charcoal, biomass
Ore and metal powder agglomeration
Ore concentrates, mill scale and metallurgical dusts are agglomerated into pellets or briquettes for recycling or furnace charging. Lignosulfonate gives green and dry strength before firing; its sulfur and alkali input is checked against the furnace limits.
What to test
- Green ball strength and drop number
- Dry and fired strength
- Sulfur and alkali input
Lignosulfonate as a metal powder binder · Lignosulfonate as a pellet binder
Foundry sand cores
In sand cores and moulds, calcium lignosulfonate is used as a water-soluble binder that gives the core strength after drying; it burns out during casting, which helps the core break down for removal.
What to test
- Dry strength
- Gas evolution during pouring
- Collapsibility after casting
Ceramic and refractory green strength
In ceramic bodies and refractory mixes, lignosulfonate acts as a temporary binder (and dispersant) that gives the formed piece strength before firing.
What to test
- Green and dry strength
- Slip or mix rheology
- Residue after firing
Ceramic & Refractory Additives · Refractory castables and ramming mixes
Carbon black pellets
Wet pelletizing of carbon black with a lignosulfonate binder is covered on the carbon black application page.
Lignosulfonate compared with molasses, starch and bentonite
| Binder | Type | Strength develops by | Points to check |
|---|---|---|---|
| Lignosulfonate (Ca / Na) | Organic, water-soluble | Drying | Water resistance; sulfur and Ca/Na added to the product |
| Molasses | Organic, sugar-based | Drying; often combined with lime to cure | Sticky handling; curing time; moisture pick-up |
| Starch | Organic, polysaccharide | Gelatinization and drying | Cooking or pre-gelatinized grade; cost |
| Bentonite | Inorganic clay | Moisture binding and firing | Ash / silica and alumina added to the product |
Binders are often combined; the choice depends on the material, the strength needed, storage conditions and what the end use allows in ash, sulfur and alkali.
Choosing a grade
| Product | Typical role |
|---|---|
| Calcium lignosulfonate | Briquette, pellet and foundry binder |
| Sodium lignosulfonate binder grade | Fast-dissolving binder for pelletizing and briquetting |
| Magnesium lignosulfonate | See magnesium lignosulfonate binder |
Typical dosage / technical notes. Dosage depends on particle size, moisture, pressing or forming conditions and required final strength, and is set by trial.
Trial checklist
- Green strength and dried strength (drop and crush tests)
- Water resistance of the dried product
- Ash, sulfur and alkali added by the binder for your end use
- Drying time and temperature
- Binder dose against cost per tonne of product
FAQ
Can lignosulfonate be used as a briquette binder?
Yes. Lignosulfonates are used as binders in briquetting and pelletizing applications where grade selection is important.
Lignin binder or molasses binder?
Both are organic binders that gain strength on drying. Molasses is often cured with lime; lignosulfonate needs no curing agent but stays water-soluble. Trials on your fines decide which gives the strength and water resistance you need, or whether a combination works best.
Which grade is commonly considered?
Calcium lignosulfonate and sodium lignosulfonate are commonly reviewed for binder applications.
What materials are commonly bound with lignosulfonate?
Coal and coke fines, charcoal, ore and metal fines, foundry sand and ceramic or refractory mixes.
What production details matter before testing a binder grade?
Particle size, moisture, target crush strength, binder dosage range, pressing method and post-drying conditions all affect binder selection and trial performance.
Other binder uses
Request Technical Recommendation
Send the material, the process, the target strength, annual consumption and destination port. Our technical team can recommend a suitable grade and provide TDS, MSDS, COA and sample support.