Through the site investigation of some passivated lime production plants in China, the working principle and grinding efficiency of different lime grinding equipment are described and compared in order to solve the issue of equipment selection in the active lime grinding process.

The analysis of working principle of ring hammer mill and its modification are carried out from the structure of the mill so that the mill can be operated on lime production line stably.

Blocking phenomenon occurs often in the rotary distributor of 600t•d-1 Maerz limekiln of the Mining Subsidiary of Handan Iron and Steel Company during production, which affects the production output and quality of active lime seriously. Through study and analysis, several modifications are done and the problem of blocking phenomenon of the distributor is solved satisfactorily. This provides the guarantee for smooth production.

The course of technical improvement of the de-dusting process system for the exhausted gas from the lime shaft kiln of Shaoguan Calcination Plant of Shaoguan Iron and Steel Group Co. Ltd. is described. After the pulse bag filter de-dusting process that is advanced in process is used to substitute the water scrubbing and spraying de-dusting process, the difficult problem of exhausted gas over-standard discharge is solved thoroughly, the good de-dusting result is obtained, and the discharge within standard and clean production are realized.

In order to meet the requirements of different users, a new type step shape shaft kiln with the mode of space calcination has been developed. The shaft kiln is characterized by material falling with pushing rod, multiple fuel adapation, less investment and high active lime reactivity. Through trial industrial use of the shaft kiln, a good result has been achieved and it has a good popularization use value.