Method and device of obtaining active lime by vacuum calcining limestone

Abstract

A process for preparing high-activity lime by vacuum calcining of lime stone includes such steps as crushing lime stone, loading in tank, heating in electric vacuum furnace at 750-900 deg.C under 100-1000 Pa, and quick cooling. Its activity is 380-450 ml.

Description

Technical field: [0001] The invention relates to the field of lime production, in particular to a method and a device for obtaining highly active lime by vacuum calcining limestone. Background technique: [0002] At present, there are two main methods of producing active lime - shaft kiln method and rotary kiln method. The pressure P in the calcination zone of the shaft kiln and the rotary kiln is 110-130kPa, and the temperature in the calcination zone is t 煅 The temperature is 1000-1200°C. The activity of the lime obtained by calcining limestone at such a high pressure and temperature is generally less than 360ml, and once it stays in the high temperature zone for a long time, the lime will sinter and become burnt lime, losing active. In recent years, there has also been a method of adding salt to calcined limestone to obtain active lime, but the activity of the lime produced by this method is generally still less than 360ml, which is generally lower than that of the shaf...

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Problems solved by technology

[0003] To sum up, the prior art has not solved the contradiction between lime activity and limestone decomposition rate—high calcining temperature, limestone decomposition rate is fast, but lime activity is low, even over-burning and losing activity; and calcining temperature is low , although the activity of lime is high, the decomposition rate of limestone is slow and the calcination time is long; while the calcination temperature is low, it may cause raw burning, which will also reduce the activity of lime

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