Lignosulfonate Lignin is used as a binder HS 3804000090

Lignin sulphonates, also referred to as lignosulphonates or lignin sulphonic salts, are by-products of paper production. Wood, the base material from which most paper is made, is primarily composed of two types of materials: carbohydrates (such as cellulose and hemicellulose) and lignins. Lignins are molecularly complex and diverse, and difficult to break down. They are undesirable within most paper, so the lignin is extracted by cooking the woody material under pressure with sulphite chemicals. This process produces a liquor containing sulfonated lignin called lignosulphonate. The liquor is purified through fermentation, which produces alcohol that is removed. During these processes, the chemicals that are used can create various lignin sulphonic salts, such as sodium lignosulphonate, calcium lignosulphonate or magnesium lignosulphonate.

The Lignosulfonate molecule is composed of about 50 phenylpropane structural units with large molecular structure and functional groups such as sulfonic acid group, phenolic hydroxyl group and carboxyl group, which makes lignosulfonate binder. In industrial production, the drip-drip acid pulping red liquid is easy to bond to other objects and dust after drying, which is related to the adhesion of lignosulfonate. Because the bond of lignosulfonate has not reached the requirement, it is necessary to enhance the bond by modification.

There are two main ways for lignosulfonate modification to be used as binder, that is, direct heating and mixing of lignosulfonate and phenolic resin, or partial substitution of lignin for phenol modified phenolic resin. The curing temperature of the modified binder is low and the curing speed is fast. Lignosulfonate is purified from natural plants, easy to biodegrade, and the modified binder is green and environmentally friendly, and the production cost is lower [. Compared with the unmodified binder, the modified binder molecule tends to diffuse on the surface of the adhesive, and the polar groups of the two are close to each other to generate electrostatic attraction, which further enhances the bonding effect.

The binder is a kind of lignosulfonate extracted by ultrafiltration from the red liquid pulped by sulfite process. It has the advantages of natural, green, low carbon and environmental protection. It can be used in the refractory industry and is a new modified product that can be used alone or in combination with other binders. Strengthening the wet strength of the embryo, especially the early strength of the hollow brick, can meet the strength needs of the manipulator. Reduce product moisture content, reduce drying time, economy and energy saving; Good plasticity, excellent demoulding performance, reduce hydraulic power consumption and mold loss, improve the service life of the mold; Compact products, reduce damage, improve the yield; The dosage only needs 0.2% ~ 0.3% (dry base), reducing the cost of use.