Naphthalene sulfonate formaldehyde sodium salts is synthesized from raw materials,crude naphthalene,sulfuric acid,formaldehyde and caustic soda,etc.

So naphthalene sulfonate formaldehyde sodium salts contains sodium sulfate.

Sodium sulfate has a feature:when working temperatures drops to below 5 ℃,sodium sulfate will crystallize,it oftern happens in winter especially in cold region.the sodium sulfate crystals will has a negative effect to concrete performance.SO try to remove this crystal...