NEWS

What is the standard for the screening rate of limestone for 325 mesh desulfurization?

Asker: Pawan
Ask date: 10/11/2018 11:42:35AM
Question: What is the standard for the screening rate of limestone for 325 mesh desulfurization?

Reply：

Dear Pawan,

Limestone (lime)-gypsum wet desulfurization is a mature and widely used desulfurization process in the world.It is preferred to use limestone as raw material. In order to ensure the comprehensive utilization of desulfurization gypsum and reduce the amount of wastewater discharged, the content of CaCO3 in the limestone used for desulfurization should be higher than 90%. The fineness of limestone powder needs to be determined based on the characteristics of limestone and the comprehensive optimization of the desulfurization system and the limestone grinding system.

For boilers burning low-sulphur fuel coal, the fineness of limestone powder should be guaranteed to be 91% of the screen passing rate of 250 mesh; when burning high-sulfur coal, the fineness of limestone powder should be guaranteed at 325 mesh 90 % pass rate. Excellent quicklime powder can also be used as the desulfurization medium, and the grade of quicklime should be higher than 85%.

To prepare limestone powder with 250 mesh or 325 mesh,the mill is mainly made up of raymond mill (pendulum mill), suspension roller mill, ball mill or European type mill. In recent years, with the demand for fineness of limestone powder and the need for energy saving and emission reduction, more and more power plants choose European mill for desulfurizing to prepare limestone powder.

MTW European type grinding mill is a new grinding equipment with the international technology level and a number of independent patented technologies developed by Kefid's experts to absorb the new European grinding technology and concept. It adopts bevel gear transmissions, internal thin oil lubrication systems and curved air ducts. It has the features of stable performance, convenient operation, low energy consumption, adjustable finished product size and equipped with special dust collector.It has been widely used in a number of power plants' desulfurization limestone milling projects.