Effects of heat and cyclic reuse on the properties of bentonite-bonded sand
Effects of heat and cyclic reuse on the properties of bentonite-bonded sand
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热和循环再利用对膨润土砂性能的影响
DOI：
10.1127/ejm/2018/0030-2784
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发表时间：
2018
影响因子：
2.1
通讯作者：
Schmahl W.W.
中科院分区：
文献类型：
--
作者：
Schiebel K;Jordan G;Kaestner A;Schillinger B;Georgii R;Hess K.-U;Böhnke S;Schmahl W.W.
膨润土结合石英砂是铸造工业中最常用的模具材料。然而，在铸造过程中，型砂会发生变化，从而使其性能变差。因此，这项工作的目的是获得准确的见解蒙皂石蚀变和属性变化之间的关系。为此，热预处理和循环再利用的砂的湿拉伸强度与水在砂内的运动学有关，如通过原位中子射线照相术和中子衍射测量的。经过22次干燥（T= 120 °C）和再润湿（3wt%）循环的砂显示出蒙脱石基底反射的d值的变化。然而，拉伸强度没有显著变化与这些修改相关。首先，用低至225 °C的温度预处理的砂显示出拉伸强度的降低，这与紧密结合的水的损失或脱羟基无关。对于高于300 °C的温度，拉伸强度的降低与紧密结合的水的损失或早期脱羟基之间的相关性是明显的。随着蒙脱石在670 °C以上完全脱羟基，观察到预热砂的湿拉伸强度的完全损失。结果表明，只要保持较低的砂温，型砂循环使用对型砂质量影响不大。对于铸造实践，结果意味着严格分离热暴露砂是有利的。
Bentonite-bonded quartz sand is the most common mould material used in foundry industry. During casting, however, the moulding sand undergoes alterations, which deteriorate its properties. Aim of this work, therefore, was to gain accurate insights into the relation between smectite alteration and property change. To this end, the wet tensile strengths of heat pre-treated and cyclically reused sands were related to the kinematics of water within the sand as measured byin situneutron radiography and neutron diffraction. Sands subjected to 22 cycles of drying (T= 120 °C) and remoistening (3 wt%) revealed modifications of thedvalues of the basal reflections of smectites. No significant change of tensile strength, however, was associated with these modifications. Contrarily, sands pre-treated with temperatures as low as 225 °C revealed a reduction of tensile strength, which was neither correlated to the loss of tightly bound water nor to dehydroxylation. For temperatures above 300 °C a correlation between the reduction of tensile strength and the loss of tightly bound water or early dehydroxylation was evident. With completing dehydroxylation of the smectites above 670 °C, total loss of wet tensile strength of the pre-heated sands was observed. The results showed that cyclic use of moulding sand had little impact on the sand quality as long as the temperature of the sand remained low. For the practice in foundry, the results imply that a rigorous separation of heat-exposed sand is advantageous.
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影响因子：
3.1
作者：
Artur Kuligiewicz;A. Derkowski
通讯作者：
Artur Kuligiewicz;A. Derkowski
Na/Ca-蒙脱石体系的水蒸气等温线和浸泡热—I：均离子粘土
DOI：
--
发表时间：
1975
期刊：
影响因子：
--
作者：
R. Keren;I. Shainberg
通讯作者：
I. Shainberg
铜 (II) 与蒙脱石的相互作用：物理方法的证据
DOI：
--
发表时间：
1974
期刊：
影响因子：
--
作者：
M. McBride;M. M. Mortland
通讯作者：
M. M. Mortland
陶瓷行业铸造副产品的回收：粘土砖中的生砂和芯砂
DOI：
--
发表时间：
2012
期刊：
影响因子：
--
作者：
R. Alonso;A. Coz;J. Viguri;A. Andrés
通讯作者：
A. Andrés
DOI：
10.1016/j.nima.2011.08.022
发表时间：
2011-12-11
影响因子：
1.4
作者：
Kaestner, A. P.;Hartmann, S.;Lehmann, E. H.
通讯作者：
Lehmann, E. H.