This paper introduces the existing national and local pollutants emission standards in Hebei,Shandong and other provinces for lime industry in China,and analyzes the reference oxygen content,the emission concentration limits and the change trends of particulate matter,sulfur dioxide and nitrogen oxide.The result shows that the most stringent limits for the above three pollutants are respectively 10 mg/m3,50 mg/m3 and 100 mg/m3, the value of reference oxygen content ranges from 8% to 10%.Based on their own conditions,lime industry enterprises should implement correct emission standards and policy requirements and do a good job in production management and environmental protection.

After 40 years of rapid development since the reform and opening up,China’s economic and social development has made historic achievements that attract worldwide attention.However,with the rapid growth of industry,the environmental situation is very grim,and the emissions of various pollutants are still at a very high level,especially in the eastern region,which is close to or exceeds the environmental capacity.The implementation of cleaner production is an inevitable trend in the development of China’s environmental protection work,an inevitable choice to realize the strategy of sustainable economic and social development,and a win-win strategy that takes into account both industrial development and environmental resources protection.

The waste gas temperature of vertical kiln is between 180 ℃ and 200 ℃,which can meet the heat requirement of waste heat boiler and meet the standard of heating and bathing.The comprehensive utilization of exhaust heat of vertical kiln responds to the national calls of energy-saving and emission-reduction and cost decreasing and effect increasing,which can save lots of cost for enterprises.

The breakage of checker brick in regenerator of the coke oven is associated with high content of impurities such as Fe2O3,K2O and so and.The used semi-silica brick composition analysis showed that the increasing amplitude of Fe2O3 and K2O are lower than fireclay brick.The main compositions of the used fireclay brick and semi-silica checker brick are kaoline, glasses phase, mullite and magnesium aluminum titanium iron oxide based precipitation phase.The Fe2O3 content in matrix phase and precipitation phase is high.The solid solution of K2O with kaoline phase reduces the melting point of check brick and the brick performance.Fe2O3 and CO undergo repeated oxidation-reduction reactions with checker bricks during the heat exchange and heating cycle of the regenerator,which is presumably the cause of excessive expansion and deformation of the volume of checker bricks.Therefore, improving the quality of bricks and reducing the impurity content are beneficial to prolonging the service life of the regenerator.

Horseshoe-shape erosion and poor tightness would occur when casting the Al2O3-C and Al2O3-ZrO2-C sliding plate for steel calcium treatment.Mechanism of damage to the Al2O3-ZrO2-C sliding plate by the calcium treatment steel during casting is analyzed in details.Al2O3-MgO-C sliding plate is developed through burning,oil immersion,and drying,which is mainly made from fused magnesia,Al2O3-MgO spinel and corundum,etc.as raw material.The diameter of the sliding plate hole is also optimized.As a result,erosion resistance of the sliding plate is effectively improved,which can be used much more times.

The un-fired and non-dipped pitch metal-ceramic bonding Al2O3-C sliding plate are developed.The phase composition and microstructure of the residual bricks are analyzed by XRD,SEM and EDS.The results show that the in-site reaction of the added metal Al powder produces a non-oxidized reinforcing phase,and its microstructure is mainly changed from carbon-bonded to non-oxide and ceramic.The non-oxide and carbon of the working layer are oxidized to form a decarbonized layer during use,resulting in loose structure and reduced strength.The hole is enlarged by the casting of high temperature molten steel,and the sliding plate working surface wears due to mechanical friction.The service life of the sliding plate is comparable to that of high temperature fired Al2O3-ZrO2-C sliding plate when used in bulk,which is superior to high temperature fired Al2O3-C sliding plate.

This paper briefly introduces the length detection method, replacement and improvement scheme and effects of double-D kiln gas gun in lime workshop of No.1 steel making plant of our company, and puts forward some suggestions on prolonging the life of the gun.

This paper introduces the enriched oxygen unit with membrane in aspects of technical features,configuration,working principle and its PLC control system,including the hardware,as well as the programming for digital I/O and analog I/O.