石灰石细度对紫色砂页岩烧结砖质量的影响

模拟砖厂现行的烧结工艺,在800℃下,通过对石灰石细度为>-1Φ、>0Φ、>1Φ、>2Φ、>3Φ和>4Φ等6种系列的紫色砂页岩砖坯小样的室内烧结实验,获得了以下认识:1)石灰石细度是影响紫色砂页岩烧结砖质量的一个至关重要的因素.在不同细度下,烧结砖发生石灰爆裂的石灰石临界含量不同,并且其临界含量随着石灰石细度的增大而降低;2)石灰石细度不同,对烧结砖质量影响的方式也不同.粒度越粗,由游离CaO吸湿消解产生的膨胀应力越集中,越容易产生石灰爆裂现象;粒度越细,产生的膨胀应力越容易被分散,越有助于减弱或消除石灰爆裂的发生.另外,建立了石灰石细度与烧结砖发生石灰爆裂的石灰石临界含量之间的关系曲线,可为砖厂的现实生产提供指导.

The Influence of Granularity of Limestone on the Quality of Sintering Bricks of Purple Sandy Shale

At 800℃,simulating active sintering process of local brickards,through indoor sintering experiment on pint-sized adobes of purple sandy shale in which granularities of limestone are >-1Φ,>0Φ,>1Φ,>2Φ,>3Φ and >4Φ,respectively,this paper draws conclusions as follows:1) the fineness of limestone is a vital factor impacting on the quality of sintering bricks of purple sandy shale.In condition of different finenesses,the critical contents of limestone which causes lime burst in sintering bricks are distinct,and lower along with augment of the fineness of limestone;2) when the finenesses of limestone are variant,their influencing modes on the quality of sintering bricks are different too.The more coarse is the grain-size of limestone,the more concentrative is the swelling stress derived from reaction between free-CaO and H2O,the more serious is the lime burst of sintering bricks,and vice versa.In addition,relation curve between the fineness of limestone and the critical contents of limestone is established,and it may guide production of local brickards.