Lime

When purchasing lime, the most critical factor is the Available Lime Content (Active CaO or Ca(OH)2). For high-grade industrial applications, look for Quicklime (Calcium Oxide) with a purity of ≥90% or Hydrated Lime (Calcium Hydroxide) with a purity of ≥92%. Additionally, monitor the Magnesium Oxide (MgO) content, which should typically be <2% for high-calcium requirements, and the particle size distribution (mesh size), as finer powders (e.g., 325 mesh) react faster in chemical processes.

Verify that the supplier adheres to ASTM C911 (for chemical lime) or ASTM C5 (for quicklime in structural use). For water treatment applications, ensure compliance with NSF/ANSI Standard 60. It is essential to request a Certificate of Analysis (COA) for every batch and check for ISO 9001:2015 certification to guarantee consistent manufacturing processes and quality control.

Quicklime is preferred in steel manufacturing (as a flux to remove impurities) and mining due to its high reactivity. Hydrated Lime is more stable and commonly used in water treatment (pH adjustment), flue gas desulfurization, and the construction industry for mortars and plasters. For environmental sectors, lime is vital for sludge stabilization and acid neutralization.

The reactivity (slaking rate) is crucial for Quicklime. High-reactivity lime reacts within 2-5 minutes, which is necessary for fast-paced industrial cycles. You should request a slaking curve report from the supplier to ensure the exothermic reaction meets your specific machinery's thermal tolerances and processing times.

Quicklime is classified as a Class 8 Corrosive Substance (UN1910) for air transport and requires careful handling for sea freight. It is highly exothermic when in contact with moisture, posing a fire risk. Ensure the supplier uses moisture-proof, UV-resistant PP woven bags with PE inner liners and that containers are hermetically sealed to prevent hydration during transit.

Utilize the Secured Trading services on Made-in-China.com to protect your payments. Before placing a bulk order, hire a third-party inspection agency like SGS or Intertek to perform a Pre-Shipment Inspection (PSI) to verify the chemical composition and weight. Always start with a sample test to confirm the lime's activity level matches the technical data sheet.

Lime is a volume-driven commodity. Negotiate based on Total Cost of Ownership (TCO), including the cost of specialized packaging and logistics. For orders exceeding 100 tons, seek a volume discount of 5-10%. Additionally, discuss long-term supply contracts to hedge against price fluctuations in raw limestone and energy costs (kiln fuel), which directly impact lime pricing.

You must ensure the supplier provides a comprehensive Material Safety Data Sheet (MSDS) in the language of the destination country. Other required documents include the Commercial Invoice, Packing List, Bill of Lading, and a Certificate of Origin. For specific regions, a GHS-compliant label must be affixed to all packaging to pass customs safety inspections.