This paper introduces the development situation of lime industry in 2018 and the technical characteristics and development trends of the rotary kiln,puts forward some solutions to the problems faced and predicts the development prospect in 2019.

This paper introduces the technical development status of mechanized lime shaft kiln with mixed fuel in 2018 and proposes improving measures for operation management and technical problems,and puts forward some thoughts and prospects for the optimization of industrial structure,upgrading of kiln equipment and green development.

Through the optimization on process operation,equipment improvement and equipment maintenance for the two internal crushing lines,the work efficiency is improved,stable supply of sintered flux products is ensured and production costs are reduced.

Aiming at the characteristics of low compressive strength of ordovician Majiagou limestone,easy to be pulverized in rotary kiln calcination process and seriously burst at low temperature,a new technology is explored to pretreat the ore,which reduces the bursting degree of ore in calcination process,improves calcination environment, realizes stable quality and increase production.

The traditional castables are prepared with calcined bauxite base material with simple particle size distribution,and filled with a lot of cement and water,resulting in larger accumulated voids.The penetration of liquid aluminium and electrolyte can not be well prevented during use.In addition,the bonding strength of high alumina cement-bonded castables is reduced due to the removal of a large amount of bonding water.When the temperature reaches between 900  ℃ and 1 100  ℃,most of the high aluminum cement bonding strength will be lost.By partly replacing the bauxite with silicon bricks and introducing water reducing agent and superfine powder into the matrix,the product performance can be effectively improved and the castables for aluminium  reduction cell can be produced.The social effect and economic benefit are obvious.

In order to solve the problems,such as low temperature hydration of magnesia based refractory bricks,temperature and pressure fluctuations and partition control of hot air volume inside the heat treated furnace,we set two preparation rooms separately at the inlet and outlet of the furnace and some hot air circulation devices inside the furnace,and took partition control of hot air volume to ensure the required thermal condition.

Used magnesia carbon bricks are produced into regenerated materials.The samples of regenerated magnesia carbon bricks contains 20% regenerated materials.The structure analysis and component analysis are studied by polarizing microscope of Axioskop40,scanning electron microscopes of XL30TMP and energy dispersive X-ray of PHOENIX.The result shows that in high temperature,magnesia particles of the regenerated materials in magnesia carbon bricks are gradually eroded from the edge,fake particles are detected in regenerated magnesia carbon bricks,and anti-oxidants in used magnesia carbon bricks are whole oxidized or partial oxidized.