赤泥加入量对赤泥烧结砖的影响

Effects of red mud content on the sintered red mud bricks

研究赤泥加入量从30%增加到60%时对烧结砖抗压强度、抗折强度、吸水率、饱和系数、体积密度、线收缩率、石灰爆裂和泛霜的影响,并对砖的赤泥加入量为30%、50%、60%的物相进行分析。结果表明,在成型压力1MPa、烧结温度950℃、保温1 h的条件下,赤泥加入量为50%,即m(赤泥)∶m(页岩)∶m(硅矿)∶m(骨料)∶m(黏土)=50∶20∶14∶10∶6时,性能最好。产品的抗压强度为24MPa,抗折强度为5MPa,吸水率为25%,饱和系数为0.905,体积密度为1.34 g/cm3,线收缩率为2.23%,无石灰爆裂,轻微泛霜。产品主要物相有玻璃相、石英、钙铝黄长石、硅灰石、霞石、硅酸铝钾,这些成分支撑了赤泥烧结砖的强度,其中钙铝黄长石有助于提高砖的抗压强度,霞石不利于抗折强度的提高。

The present essay is to study the effect of red mud content on the property of sintered red mud bricks.The recent fact is that while making the bricks,the red mud addition has been increased form 30% to 60% to the unfired bricks.In order to make clear the real effect of red mud addition on the quality of the bricks,we have tested the compression strength and break strength of the said bricks along with their water absorption and saturation efficiency when added with red mud.When we tested the bulk density and the line shrinkage of the said bricks,we have noticed that when the red mud addition takes account for 30%,50% and 60%,the results indicate that the better properties could be achieved under the optimum conditions,which stand as follows： the optimal briquetting pressure is 1 MPa,the calcination temperature should be 950 ℃ and the calcination time should be one hour.And the raw material ratio should be that： the red mud accounts for half of the total amount,the shale accounts for 20% of the total amount,whereas the silicon ore should take 14% of the total composition.As to the aggregate,it should account for 10% of the total sum,but the clay just takes 6% of the total constitution.The ideal properties of the brick should be as follows： the compressive strength of sintered brick should reach 24 MPa whereas the break strength is 5 MPa.The moisture absorptive power should be 25% and the saturation coefficient is 0.905.However,the bulk density proves lower,that is,only 1.34 g/cm3 while the linear shrinkage is 2.23%.In addition,the added composition should also contain glass phase,quartz,gehlenite,wollastonite,nepheline and potassium aluminium silicate in the bricks,which can contribute to the strength of the said bricks.The gehlenite in the brick composition can also help to improve its compressive strength,though the nepheline may not be good for the flexural strength improvement.