Calcined magnesite powder

The most critical factor is the MgO (Magnesium Oxide) content, which typically ranges from 75% to 95%. For industrial applications like floor flooring or abrasive stones, a purity of 85-90% is standard. You must also specify the Activity (Reactivity), often measured by the citric acid test, as this determines how the powder reacts with magnesium chloride. Additionally, pay close attention to the Particle Size (Mesh); common requirements are 200 mesh or 325 mesh to ensure a smooth finish in end-products.

For agricultural or animal feed grades, ensure the product is Heavy Metal Compliant (Lead, Arsenic, and Mercury limits) and carries FAMI-QS or ISO 22000 certifications. For construction use (MGO boards), the LOI (Loss on Ignition) should be strictly controlled, usually between 4% and 9%, to prevent cracking or instability in the final cementitious structure. Always request a COA (Certificate of Analysis) from the latest production batch.

It is widely used in Hydrometallurgy for precipitating metals, in Environmental Protection for flue gas desulfurization and wastewater treatment, and in Agriculture as a fertilizer or feed additive. In the building sector, it is the core ingredient for Magnesium Oxychloride Cement (MOC) used in fireproof boards, lightweight wall panels, and grinding wheels.

The primary risk is Quality Inconsistency between the sample and the bulk cargo, as magnesite is a natural mineral. To mitigate this, use Third-Party Inspection services (like SGS or Intertek) at the loading port to verify MgO content and particle size. Another risk is Moisture Absorption; since the powder is chemically active, it can absorb moisture from the air during sea transit, leading to caking. Ensure the supplier uses Jumbo bags with inner PE liners and moisture-proof seals.

Focus on Volume-Based Pricing; because this is a bulk commodity, a 500-ton order can significantly reduce the per-ton price compared to a 20-ton trial. Ask for Tiered Pricing based on MgO purity levels. Furthermore, negotiate Payment Terms that include a percentage held until the Pre-shipment Inspection (PSI) is passed. For long-term cooperation, seek a Price Adjustment Formula linked to raw magnesite ore market indices.

Calcined Magnesite is generally classified under HS Code 251990. It is usually shipped in 20ft Containers (maximized for weight, typically 25-28 tons) or as Break Bulk for very large orders. Check your local Import Duties and whether your country requires a Phytosanitary Certificate (if used for agriculture) or specific MSDS (Material Safety Data Sheets) for customs clearance. Ensure the Incoterms are clearly defined, preferably FOB or CIF, to manage logistics risks effectively.