Preparation of Low Ratio Magnesium Ccement by Acid Leaching Treatment of Boron Mud  

作　　者：YANG Mei ZHANG Mingzhe CHEN Hao 杨梅(School of Materials Science and Engineering,Shenyang Jianzhu University,Shenyang 110168,China)

机构地区：[1]School of Materials Science and Engineering,Shenyang Jianzhu University,Shenyang 110168,China [2]School of Physical Science and Technology,Shenyang Normal University,Shenyang 110168,China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2025年第1期120-129,共10页武汉理工大学学报（材料科学英文版）

基　　金：Funded by Provincial Basic Research Projects(No.LJKMZ20220947)。

摘　　要：The effects of liquid-solid ratio and reaction time on the leaching rate of magnesium at room temperature were investigated,as well as the effects of the molar ratio of MgO/MgCl_(2),the amount of water added,and the amount of acid-impregnated slag dosed on the compressive strength and water resistance of LR-MOC.The results showed that the magnesium element in the boron mud could be maximally leached under the conditions of 1:1 concentration of hydrochloric acid at room temperature,liquid-solid ratio of 2.5 mL·g^(-1),and reaction time of 5 h,and the main products were amorphous SiO_(2) as well as a small amount of magnesium olivine which had not been completely reacted.The LR-MOC prepared using the acid-soaked mixture could reach a softening coefficient of 0.85 for 28 d of water immersion when the molar ratio of MgO/MgCl_(2) was 2.2,the amount of water added was 0 g,and the acid-soaked slag dosing was 40 wt%,which also led to an appreciable late-strength,with an increase of 19.4%in compressive strength at 28 d compared to that at 7 d.Unlike previous studies,LR-MOC prepared in this way has a final strength phase that is not the more easily hydrolysed 3-phase but the lath-like 5-phase.For this phenomenon,we analyzed the mechanism and found that,during the acid leaching process,a part of amorphous SiO_(2) dissolved in the acid leaching solution formed a silica sol,in which Mg^(2+)played a bridging role to make the silica sol more stable.With the addition and hydrolysis of MgO,the silica sol gel coagulation slows down,providing a capping layer to inhibit the hydrolysis of the 5-phase crystals and providing some strength after coagulation.The amorphous SiO_(2) in the other part of the acid-impregnated slag generated M-S-H gel with Mg^(2+)and OH-,which synergised with the dense structure composed of interlocking crystals to improve the water resistance of LR-MOC.

关 键 词：boron mud magnesium chloride-oxygen cement acid immersion water resistance silica sol 

分 类 号：TQ172.1[化学工程—水泥工业]