Caustic Soda Pearls

About This Product

Caustic soda pearls are solid sodium hydroxide (NaOH, CAS 1310-73-2) in the form of small, free-flowing spheres. They are made by spraying molten anhydrous caustic soda into the top of a prilling tower, where the droplets solidify as they fall. The listed product is a technical grade at 99.0% NaOH minimum with a pearl size of 0.4–0.6 mm. The uniform size is the point of the form: pearls pour, meter and weigh predictably, dissolve evenly and produce less dust than flakes. Pearls and flakes are chemically identical and a producer's two forms usually share one specification, so the choice is about handling. Pearls are the natural fit for screw and vibratory feeders, weigh hoppers and automatic dosing on clean-in-place and bottle-washing plants, and for dry blending with other powders, where a narrow particle size reduces segregation in the finished blend. Beyond technical grade, rayon, food (E524) and pharmacopoeia grades exist as separate products with their own purity criteria; technical pearls are not for food or pharmaceutical use. In detergent powders, dishwasher products and drain-cleaner granules, pearls supply the alkalinity that saponifies fats and breaks down protein soils. Small soap makers and laboratories prefer them because they can be weighed accurately with little dust. In water and effluent treatment they raise pH and precipitate metals as hydroxides without adding hardness, and in textile processing they serve scouring and mercerising baths. Chemical and metal-finishing plants use them for pH control and alkaline cleaning. The parameters buyers agree are the NaOH assay, sodium carbonate, sodium chloride and iron, plus the particle size range where pearls feed dosing equipment. Carbonate is worth watching because it rises whenever the product is exposed to air. Check every batch certificate of analysis against the agreed limits, and if you are switching from flakes, substitute on a like-for-like NaOH basis. Under CLP, pearls carry the same classification as any solid caustic soda: severe skin burns and eye damage (H314) and possibly corrosive to metals (H290). They ship as UN1823, SODIUM HYDROXIDE, SOLID, Class 8, packing group II, and classify under HS 2815.11 like every solid form. Treat the safety data sheet for the supplied product as the controlling document. For imports into the EU or Great Britain, ask which company holds the REACH or UK REACH registration that covers your import and use. Because pearls dissolve faster than flakes, they also release their heat of solution faster, so add them gradually to cold, stirred water, never water to caustic, and take extra care in small vessels. Pearls lose their free flow once they absorb moisture, so store bags sealed in a dry, covered area away from acids, ammonium salts and aluminium or galvanised metal, and reseal part-used bags at once. When you enquire, state the grade, NaOH minimum and impurity limits, any particle-size requirement for your feeder, the pack format, the volume per shipment and per year, and the destination and Incoterms.