Lime can no longer burn burn again
Quicklime generally contains excessive lime, excessive lime ripening slow, and if the lime paste hardening occurs again after ripening, will cause swelling and cracking caused by aging. In order to eliminate the harm of excessive lime, lime should be aged about 2 weeks after ripening.
Production process: the original lime production process is to limestone and fuel (wood) layered laying, firing for a week to get calcined. In modern times, mechanical, semi mechanized kiln, rotary kiln, boiling furnace and other equipment are used for production. The calcination time is correspondingly shortened, and the production of lime with rotary kiln only takes 2~4 hours, and the production efficiency can be increased by more than 5 times compared with the vertical kiln. In recent years, there have been cross flow type, double slope type and oil burning circular kiln and short rotary kiln with preheater. The energy-saving process and equipment have been greatly improved. The fuel has also been expanded into coal, coke, heavy oil or liquefied petroleum gas.
In practical production, the calcination temperature is usually increased to 1000~1100 DEG C for accelerated decomposition. Owing to the large size of limestone raw material or uneven temperature distribution during calcination, lime and lime are often contained in lime. Calcium carbonate in poor lime is not completely decomposed and lacks cohesive force when used. Excessive lime structure is dense, and the surface is often coated with a layer of molten material, melting very slowly. Because the production of raw materials often contain magnesium carbonate (MgCO3), because this lime also contains minor components of Magnesium Oxide (MgO), according to the number of Magnesium Oxide content, lime into calcium lime (MgO = 5%) and magnesia lime (MgO>5%).
Any natural rock consisting mainly of calcium carbonate, such as limestone, chalk, dolomitic limestone, etc., can be used to produce lime.
Can the lime as the main component of calcium oxide, usually method was mainly composed of calcium carbonate rock, calcined at high temperature, then decomposition of carbon dioxide and calcium oxide (chemical formula: CaO, namely lime, also known as Yun Shi).
