Overview
Quicklime Lump, or calcium oxide (CaO), is produced by calcining limestone (CaCO₃) at high temperatures (~900–1,200°C). It is a cornerstone material in industrial processes due to its high reactivity and alkaline nature. In metallurgy, it is essential for slag formation to remove impurities during steel production. Its exothermic reaction with water (slaking) also makes it valuable in construction and environmental applications. Historically, quicklime has been used since ancient times for mortar and soil stabilization. Modern production methods ensure consistent quality, with lump forms preferred for controlled reactivity in bulk handling. Industrial grades prioritize low silica and sulfur content to avoid detrimental effects in steelmaking.
Physical and Chemical Properties
Quicklime Lump is characterized by its high melting point (2,572°C) and density (3.34 g/cm³), making it stable under extreme conditions. It reacts vigorously with water to form calcium hydroxide (slaked lime), releasing significant heat—a property leveraged in self-heating materials and wastewater treatment. The compound is insoluble in organic solvents but reacts with acids to form salts. Its hygroscopic nature necessitates dry storage to prevent premature slaking. Particle size and porosity affect reactivity, with finer lumps offering faster reaction rates. Industrial specifications often include tests for available lime index (AVI) to quantify active CaO content, typically targeting ≥90% for slagging applications.
Main Applications
In steelmaking, Quicklime Lump is a fluxing agent to form slag, which absorbs phosphorus, sulfur, and silica impurities. The basicity of CaO ensures efficient impurity removal, improving steel quality. Construction industries use it to produce lime mortar, plaster, and stabilized soils, benefiting from its binding properties and low cost. Environmental applications include pH adjustment in water treatment and flue gas desulfurization (FGD). It also serves as a precursor in chemical synthesis, such as calcium carbide or bleaching powder production. Emerging uses include biodiesel catalysis and hazardous waste stabilization, showcasing its versatility.
Safety and Storage
Quicklime is a corrosive substance that can cause severe burns upon contact with skin or eyes. Dust inhalation may lead to respiratory irritation. Strict PPE (gloves, goggles, respirators) is mandatory during handling. Storage requires airtight, moisture-proof containers or silos to prevent unintended slaking and heat generation. Spills should be neutralized with dry sand or vermiculite, not water, to avoid exothermic reactions. Facilities must ensure adequate ventilation to disperse dust. Transport regulations often classify it as a hazardous material, requiring UN1910 labeling for international shipments.
B2B Procurement Guide
When sourcing Quicklime Lump, prioritize suppliers with ISO or metallurgical-grade certifications. Key parameters include CaO content (≥90%), low magnesia (<2%), and minimal impurities (e.g., SiO₂ <1.5%). Bulk purchases should assess logistics, as moisture exposure during transit can degrade quality. Pricing fluctuates with energy costs (calcination is energy-intensive) and regional availability. Long-term contracts may offer stability. For steel plants, just-in-time delivery minimizes storage risks. Always request Material Safety Data Sheets (MSDS) and batch-specific certificates of analysis.