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Cement kiln using basic refractory requirement and using
by Lili Han okordermaterials 1. The new dry process cement kiln refractory material usedLarge SP kiln and PC kiln kiln cylinder, directly combined magnesite chrome brick used for calcining zone, spinel brick or easy hanging furnace leather and good thermal shock stability magnesite-chrome brick is used in the transition zone, high alumina brick is used to decompose belt, insulation type alkali clay brick or ordinary clay bricks for kiln cylinder rear, refractory castable or before and after the apply of refractory brick used in kiln mouth;Within the preheating system normal alkali clay brick and alkali resistant castable used in vaults, duct type high strength alkali clay bricks used in three times, and with a lot of refractory castable, insulating brick series and series of calcium silicate board.Within YaoMen cover and cooling machine system, in addition to choose the material, also with silica carbide and silicon carbide composite brick, series, series of refractory castable, insulating brick series calcium silicate board and refractory fiber material seven categories of more than 30 kinds of refractory materials.On the nissan 2000 tons of cement kiln, brick building consumption of 1600 tons, dosage of normal production at the age of consumption of 400 tons.
2. Precalcining kiln demand for refractories
System of cement rotary kiln speed slow, precalcining kiln speed is 3 ~ 4 times of traditional cement kilns, high temperature and high speed and large diameter, kiln, kiln lining the preassigned transfer solution of thermal stress than the traditional cement kiln.The preheater, humidifying tower, electric dust collection for many times, precalcining kiln of K2O, difficult to overflow after SO2, KCl and other components of volatile kiln system.When after the establishment, sulfur, chlorine alkali balance, the volatile components in the furnace has a high concentration, significantly affect the service life of cement production and refractory materials.Precalcining kiln can bring considerable benefits, but the significant increase in the complexity of the kiln.Each part of the kiln problems may result in production.Therefore, require cement precalcining kiln refractory material used should have excellent quality and high stability.
System of cement rotary kiln speed slow, precalcining kiln speed is 3 ~ 4 times of traditional cement kilns, high temperature and high speed and large diameter, kiln, kiln lining the preassigned transfer solution of thermal stress than the traditional cement kiln.The preheater, humidifying tower, electric dust collection for many times, precalcining kiln of K2O, difficult to overflow after SO2, KCl and other components of volatile kiln system.When after the establishment, sulfur, chlorine alkali balance, the volatile components in the furnace has a high concentration, significantly affect the service life of cement production and refractory materials.Precalcining kiln can bring considerable benefits, but the significant increase in the complexity of the kiln.Each part of the kiln problems may result in production.Therefore, require cement precalcining kiln refractory material used should have excellent quality and high stability.
3. The new requirements for basic refractory cement industry
At present, magnesite chrome bricks in building materials industry will take approximately more than 60000 tons, produce residual brick containing 0.3% Cr6, plus about 24000 tons.Rotary kiln cement production in 2010 will reach 800 million tons, the consumption of building materials industry in magnesite-chrome brick is 500000 tons.
Magnesite chrome bricks in use will generate highly toxic and carcinogenic hexavalent chromium.Cr6, + can cause skin damage, upper respiratory tract inflammation, mucosal ulcers, skin cancer and lung cancer.Chromium resources in our country, the building materials industry emissions Cr6, + seriously polluted the environment.Basic refractory with high temperature calcination and excellent characteristics of resistance to chemical attack ability is strong, is to realize the cement kiln production of high quality, high yield, low consumption and long term operation of the key of kiln lining materials.But it is easy to be affected with damp be affected with damp metamorphism, thermal expansion rate, high coefficient of thermal conductivity and thermal shock stability is poorer.Currently applied to cement kiln of imported and domestic alkaline refractory materials mainly include direct combination of magnesite chrome brick, half direct magnesite chrome brick, the common magnesia chrome brick, dolomite brick, containing zirconium and does not contain all kinds of special magnesite brick, zirconium spinel brick and chemical combination is not burned magnesite chrome brick, etc.
Common magnesia-chrome brick containing 8% ~ 10% Cr2O3 often, directly combined magnesite chrome brick reached 10% ~ 16%, adding the function of chrome ore is significantly improve the performance of thermal shock stability on the brick.But they are in the cement kiln (especially the new dry process cement kiln) using alkali erosion, vulnerable to generate K2CrO2 containing hexavalent chromium minerals such as release to the environment, after using the residual brick contains 3 ca ยท CaCr03 such as water soluble minerals containing hexavalent chromium pollution also downstream water, the chromium pollution caused by human.In order to improve the erosion resistance of brick, and reduce or even eliminate the cause of chromium pollution to environment, development and utilization of foreign low chromium magnesite chrome brick, no special magnesite brick and dolomite brick etc new basic refractory has been successful.Poor chrome ore resources in China, and out-of-the-way place XiChui xinjiang, Tibet, chrome alloy steel imports are expensive, on the cement kiln at low chromium, no chrome brick instead of a high chromium of common magnesia-chrome brick and direct combination of magnesite chrome brick demand more urgent.
Long-term use of magnesite chrome bricks as cement rotary kiln thermal belt furnace lining.Use, part of the chrome brick will shift from Cr3, + is highly toxic and carcinogenic Cr6, +. Provisions in China standard: environmental water level IV Cr6, + content should be < 0.05 mg/l, grade I Cr6, environment water + content should be < 0.01 mg/l. the Cr6, magnesium chromium residue brick + is up to 2577 mg/kg. This is to say, can remove the residual brick pollution is 50000 ~ 250000 times its weight of water, seriously damaged the environment and threaten people's health.
More than a decade, refractory industry at home and abroad in search of magnesite chrome brick replacement materials has made a lot of work, but the effect is not ideal.China building materials science research institute under the support of national 863 project, an in-depth research on the issue.The results show that the Cr2O3 in magnesia refractory increase direct bonding degree, reduce erosion rate, improve thermal shock resistance and improve kiln skin adhesion effect.In short, China's cement industry towards the goal of modernization, need high quality of the environment friendly basic refractory.
4. The refractory industry to solve the problem
(1) green manufacturing is the main characteristic of refractories production technology in the new century.Represents the main ideas of green 3 r principle: Reduce, Reduce consumption, Reuse, Reuse, Recycle - recycling.In human population expansion, resource depletion and environmental damage, under pressure to achieve sustainable development we must use some now cannot use material, try to reuse the abandoned materials.
(2) reduce production and improve quality.Refractories production in our country of the world's first, cheap products, high-grade products, cement kiln refractory material used.In the future should be more high middle-grade products, stable product quality, and reasonable, cement kiln with the production and use of refractory materials are in the best state.
(3) improve the equipment.Improve the level of refractory plant production equipment, the production of high quality refractory material is one of the key, it directly affect product quality and overall dimensions, ill-equipped of refractory plant in our country, should be taken into consideration seriously.At the same time should strengthen the regulations and standards system construction, to promote cleaner production in accordance with the law.
At present, magnesite chrome bricks in building materials industry will take approximately more than 60000 tons, produce residual brick containing 0.3% Cr6, plus about 24000 tons.Rotary kiln cement production in 2010 will reach 800 million tons, the consumption of building materials industry in magnesite-chrome brick is 500000 tons.
Magnesite chrome bricks in use will generate highly toxic and carcinogenic hexavalent chromium.Cr6, + can cause skin damage, upper respiratory tract inflammation, mucosal ulcers, skin cancer and lung cancer.Chromium resources in our country, the building materials industry emissions Cr6, + seriously polluted the environment.Basic refractory with high temperature calcination and excellent characteristics of resistance to chemical attack ability is strong, is to realize the cement kiln production of high quality, high yield, low consumption and long term operation of the key of kiln lining materials.But it is easy to be affected with damp be affected with damp metamorphism, thermal expansion rate, high coefficient of thermal conductivity and thermal shock stability is poorer.Currently applied to cement kiln of imported and domestic alkaline refractory materials mainly include direct combination of magnesite chrome brick, half direct magnesite chrome brick, the common magnesia chrome brick, dolomite brick, containing zirconium and does not contain all kinds of special magnesite brick, zirconium spinel brick and chemical combination is not burned magnesite chrome brick, etc.
Common magnesia-chrome brick containing 8% ~ 10% Cr2O3 often, directly combined magnesite chrome brick reached 10% ~ 16%, adding the function of chrome ore is significantly improve the performance of thermal shock stability on the brick.But they are in the cement kiln (especially the new dry process cement kiln) using alkali erosion, vulnerable to generate K2CrO2 containing hexavalent chromium minerals such as release to the environment, after using the residual brick contains 3 ca ยท CaCr03 such as water soluble minerals containing hexavalent chromium pollution also downstream water, the chromium pollution caused by human.In order to improve the erosion resistance of brick, and reduce or even eliminate the cause of chromium pollution to environment, development and utilization of foreign low chromium magnesite chrome brick, no special magnesite brick and dolomite brick etc new basic refractory has been successful.Poor chrome ore resources in China, and out-of-the-way place XiChui xinjiang, Tibet, chrome alloy steel imports are expensive, on the cement kiln at low chromium, no chrome brick instead of a high chromium of common magnesia-chrome brick and direct combination of magnesite chrome brick demand more urgent.
Long-term use of magnesite chrome bricks as cement rotary kiln thermal belt furnace lining.Use, part of the chrome brick will shift from Cr3, + is highly toxic and carcinogenic Cr6, +. Provisions in China standard: environmental water level IV Cr6, + content should be < 0.05 mg/l, grade I Cr6, environment water + content should be < 0.01 mg/l. the Cr6, magnesium chromium residue brick + is up to 2577 mg/kg. This is to say, can remove the residual brick pollution is 50000 ~ 250000 times its weight of water, seriously damaged the environment and threaten people's health.
More than a decade, refractory industry at home and abroad in search of magnesite chrome brick replacement materials has made a lot of work, but the effect is not ideal.China building materials science research institute under the support of national 863 project, an in-depth research on the issue.The results show that the Cr2O3 in magnesia refractory increase direct bonding degree, reduce erosion rate, improve thermal shock resistance and improve kiln skin adhesion effect.In short, China's cement industry towards the goal of modernization, need high quality of the environment friendly basic refractory.
4. The refractory industry to solve the problem
(1) green manufacturing is the main characteristic of refractories production technology in the new century.Represents the main ideas of green 3 r principle: Reduce, Reduce consumption, Reuse, Reuse, Recycle - recycling.In human population expansion, resource depletion and environmental damage, under pressure to achieve sustainable development we must use some now cannot use material, try to reuse the abandoned materials.
(2) reduce production and improve quality.Refractories production in our country of the world's first, cheap products, high-grade products, cement kiln refractory material used.In the future should be more high middle-grade products, stable product quality, and reasonable, cement kiln with the production and use of refractory materials are in the best state.
(3) improve the equipment.Improve the level of refractory plant production equipment, the production of high quality refractory material is one of the key, it directly affect product quality and overall dimensions, ill-equipped of refractory plant in our country, should be taken into consideration seriously.At the same time should strengthen the regulations and standards system construction, to promote cleaner production in accordance with the law.
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About Lili Han 
okordermaterials
4 connections, 0 recommendations, 19 honor points.Joined APSense since, April 22nd, 2014, From Beijing, China.
Created on Dec 31st 1969 18:00. Viewed 0 times.
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