Process for preparing magnesium borate whiskers with high aspect ratio by utilizing carnallite

• Main Authors: MENG QINGFEN, ZHU DONGHAI, BIAN SHAOJU, LI WU, SUN QIUJU, NAI XUEYING, DONG YAPING, LU HUIGANG
• Format: Patent
• Language: Chinese; English
• Published: 29.12.2010
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; CHEMISTRY; CRYSTAL GROWTH; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

The invention relates to a process for preparing magnesium borate whiskers with high aspect ratio by utilizing carnallite, comprising the following steps: (1) pretreatment: proportionally dissolving carnallite in water, removing the undissolved substances by filtration and obtaining the carnallite solution; (2) mixing reaction: mixing boric acid, alkali, fluxing agents and the carnallite solution obtained in the step (1) to react and then sieving the reactants after drying the reactants at 50-200 DEG C and grinding the dried reactants to obtain the sintering materials; (3) sintering: heating the sintering materials obtained in the step (2) under the constant temperature of 750-950 DEG C for 2-10h and obtaining sinter cakes after natural cooling; and (4) aftertreatment: obtaining filter residues and filtrate after infiltrating the sinter cakes in water at 50-95 DEG C and centrifugally washing the sinter cakes, obtaining the magnesium borate whiskers after the filter residues are dried and simultaneously obtain