Limestone Grinding Process

2021-05-17

Limestone is the main raw material for the production of cement, concrete coarse and fine aggregates, lime, etc. Its crushing and grinding are generally dry process, and the corresponding process is selected according to different application fields:

For limestone used in metallurgy and road construction, the ore is generally crushed and screened.

For the 250-45μm fine powder products used as feed additives and common fillers, the ore is generally crushed by a particle crusher, hammer crusher, impact crusher, etc. directly with Raymond mill, vertical mill, roller mill, etc. , Impact mill and other grinding.

For the ultrafine limestone powder and high-grade fillers used for flue gas desulfurization, ultrafine pulverization and fine classification are generally required, and the process equipment is basically the same as the ultrafine calcite pulverization.

At present, most of the limestone powder used in the building materials industry is to grind limestone or stone chips produced in the process of aggregate production to make the fineness meet the specified requirements.

Limestone Grinding Process

The limestone grinding process mainly includes two types:

Open circuit process: The process in which the material passes through the mill once and is used as a finished product for the next operation;

Closed-circuit process: when the material is separated from the mill by one or several levels, the fine particles are used as the finished product, and the coarse particles are returned to the mill for re-grinding.

The opening process is relatively simple, with the advantages of less equipment, less investment, and simple operation. However, because the materials need to meet the fineness requirements before they can be milled, over-grinding is prone to occur, and the finely ground materials easily form a cushion layer, which prevents the coarse materials from further grinding, greatly reduces the grinding efficiency and increases the power consumption.

Therefore, most limestone powder manufacturers currently choose a closed-circuit process, which can reduce the phenomenon of over-grinding, improve the efficiency of the mill, and reduce energy consumption. In addition, the limestone powder produced by the closed-circuit process has uniform particle size and is easy to adjust, which can meet the requirements of different finenesses.