Quicklime[2]

Updated: 2026-09-16

Overview

Quicklime, or calcium oxide (CaO), is a fundamental chemical compound produced by heating limestone (calcium carbonate) in a kiln. This process, known as calcination, drives off carbon dioxide, leaving behind the highly reactive quicklime. It has been used for centuries in construction, agriculture, and industrial processes due to its versatile properties. Quicklime is known for its strong alkaline nature and exothermic reaction when mixed with water, producing slaked lime (calcium hydroxide). This reaction is harnessed in various applications, from mortar production to pH adjustment in water treatment.

Physical and Chemical Properties

Quicklime appears as a white to grayish-white solid with a crystalline structure. It has a high melting point of 2,572°C and a boiling point of 2,850°C, making it stable at high temperatures. Its density is approximately 3.34 g/cm³, and it reacts vigorously with water, releasing significant heat. The compound is highly alkaline and reacts with acids to form salts. It is insoluble in most organic solvents but dissolves in acids. Quicklime’s reactivity with water makes it hygroscopic, requiring careful storage to prevent unintended reactions.

Main Applications

Quicklime is a cornerstone in the construction industry, where it is used to produce mortar, plaster, and limewash. Its ability to stabilize soil makes it valuable in road construction. In steel manufacturing, quicklime acts as a flux to remove impurities during the smelting process. Water treatment facilities use quicklime to adjust pH levels and soften water. It is also employed in chemical synthesis, particularly in producing calcium hydroxide and other calcium-based compounds. Additionally, quicklime is used in waste treatment to neutralize acidic waste and reduce odors.

Safety and Storage

Quicklime poses several hazards, including severe skin and eye irritation upon contact. Inhalation of dust can cause respiratory issues, making proper ventilation and personal protective equipment (PPE) essential. It should be stored in airtight containers in a dry environment to prevent moisture absorption. In case of exposure, affected areas should be rinsed immediately with plenty of water. Quicklime fires should not be extinguished with water due to the exothermic reaction; instead, use dry chemical extinguishers. Proper labeling and handling protocols are critical to ensuring workplace safety.

B2B Procurement Guide

When procuring quicklime, prioritize suppliers with a proven track record of quality and reliability. Key factors to consider include purity (typically 90-95% CaO), packaging integrity, and compliance with safety standards. Bulk purchases often offer cost savings, but ensure storage facilities are moisture-free. Request certificates of analysis (CoA) to verify chemical composition. Evaluate transportation logistics, as quicklime is sensitive to environmental conditions. Establishing long-term contracts with reputable suppliers can secure consistent quality and pricing.