What is Magnesium Chloride Flake?

Magnesium chloride flake comes straight from the evaporation of brine or sea water, shaping up as thin, white to pale gray flakes. The product often carries a bright, slightly bitter taste and dissolves easily in water, giving a clear solution that holds much promise in different chemical and industrial settings. People see it as a stable salt that finds use in a surprising number of areas—deicing roads in the winter, dust control, making textiles, supporting agriculture, and even stepping into nutritional roles. The HS Code for magnesium chloride usually runs under 28273100, which helps identify it quickly for customs and logistics. Looking at the molecular formula, you get MgCl₂·6H₂O for the hexahydrate form that dominates the market. Magnesium chloride arrives not only as flakes, but also as powder, pearls, compact crystals, and sometimes as a ready-made liquid solution. The specific density swings between 1.56 g/cm³ and 1.65 g/cm³, so it sinks well in water, and its solid state holds up under regular room temperatures—great for handling and storage.

Chemical Properties and Structure

Magnesium chloride is made up of magnesium ions and chloride ions, connected by ionic bonds, creating a solid crystal lattice structure. Each molecule sticks to six water molecules, giving it a hydrated state you can actually feel when touching the flakes—there’s a bit of softness, almost a waxy feel. Its molecular weight gets calculated at about 203.3 g/mol when considering the hexahydrate version. This material melts at 117°C, but when you keep it heated above that point, it begins to lose water, shrinking down to the anhydrous form. The water solubility is remarkable, making it effective wherever fast dissolution is required. Its pH is near neutral in solution, which means there aren't harsh reactions when adding to water. That specific behavior gives people flexibility in process industries, especially those that can’t tolerate strong acids or bases. In my chemical handling experience, the visual and physical differences between powder, pearls, and flakes really depend on the drying and crystallization process. Powder clumps up faster in humid air, while flakes hold their form better over time.

Applications and Raw Material Insight

Uses for magnesium chloride start with the raw material itself—typically extracted from brine pools, sea water, or underground deposits where magnesium salts naturally concentrate. Processing strips away other minerals, leaving nearly pure MgCl₂, often with a faint trace of minerals like calcium or sodium. For roads, it beats out rock salt by being less corrosive and working at lower temperatures. In agriculture, it improves soil structure and pulls some double duty by supplying magnesium, an essential plant nutrient. I’ve seen dusty driveways in rural areas trade patchy, flying gravel for a smooth track after a proper magnesium chloride application in late spring. Factories lean on it, too, using the flakes to condition textiles, in firefighting agents, and to set dyes. Food processors use it as a coagulant for tofu—though only the food-grade type qualifies here—and it even treats water by pushing out heavy metals. That’s a level of versatility not many chemicals offer. As a raw material, it leaves a small, reliable supply chain footprint compared to more complex compounds that pull on rare metals or hazardous reactants.

Handling, Safety, Hazard, and Health

Anyone storing or working with magnesium chloride has to care about safe storage and transport, even if it’s seen as mild compared to alkalis or heavy oxidizers. The flakes can draw moisture from the air, so sealed containers are a must. If left exposed, they clump or begin to turn liquid. Personal protective equipment (PPE) should include gloves and eye protection—not because it’s acutely toxic but since the salt can irritate sensitive skin and eyes. Inhalation of dust is not recommended. Spills clean up with water, but run-off should stay controlled to avoid impact on local water bodies, as high concentrations change pH and may harm aquatic life. Short-term contact rarely causes serious harm; chronic skin exposure or accidental ingestion in large amounts could upset electrolyte balance, especially for people already at risk. In my old shop, a bag tore on a humid day, and within an hour the workbench was just as sticky as a salt marsh. That was enough to drill home the value of simple containment. While enviro agencies do not class it as a hazardous material on the same level as strong acids or alkalis, magnesium chloride deserves respect like any industrial-grade chemical. Waste and spills ought to be managed with local guidelines top of mind.

Specifications and Standards

Industry standards expect magnesium chloride flakes to include between 46% and 48% pure MgCl₂ by weight, with the rest being water and trace minerals. Bulk density commonly lands around 0.85 to 0.95 g/cm³, which affects packaging and transport costs. The crystals should remain free-flowing, white or off-white, and nearly odorless. Most suppliers certify against sharp limits for heavy metals, non-soluble matter, and foreign substances. Whether ordering for deicing or for use in specialty chemicals, users want a full certificate of analysis attached to every batch. Market options range from 25 kg bags to one-tonne bulk sacks, with labeling showing HS Code, net weight, gross weight, and batch/lot ID for traceability. In my procurement experience for bulk chemicals, a shipment missing paperwork or arriving with caked blocks instead of flakes was a red flag—suggesting either poor storage or diluted raw materials. Reliable quality and documentation not only keep buyers confident; they support downstream uses where technical consistency isn’t just a preference but a requirement by law.