Zur Chemie und Konstitution borsaurer Salze. XVI. Über die Hydrate des Magnesium(1:3)‐borates, MgB₆O₁₀ · x H₂O

Abstract

Mit steigender Konzentration der Komponenten MgO und H3BO3 treten relativ unabhängig von der Temperatur bei B/Mg · 6 nacheinander die Hydrate MgB6O10 · 7,5 H2O, MgB6O10 · 7 H2O, MgB6O10 · 6 H2O und MgB6O10 · 5 H2O im System MgOB2O3H2O auf. Die gleichen Substanzen sind auch im System MgOB2O3H2OMgCl2 Bodenkörper. Das 7‐ und 6‐Hydrat sind hier in bezug auf MgB6O10 · 5 H2O unter der Mutterlauge metastabil. Bei der Entwässerung liefert lediglich das 7‐Hydrat nach Verlust von 2 Mol H2O eine definierte Hydratstufe; diese, MgB6O10 · 5 H2O (T), wässert über die Dampfphase wieder zum 7‐Hydrat an und ist vom zuerst genannten 5‐Hydrat verschieden.

Effect of Magnesium Borates on the Fire-Retarding Properties of Zinc Borates

“…At all the reaction temperatures and reaction times, Mcallisterite is observed to be the major phase, whereas admontite is major only at 70 ∘ C and 90 min. These results are also consistent with the results reported in Derun et al [26] and Lehmann and Rietz [29], where the authors synthesised different types of magnesium borates (MgB 6 O 10 ⋅ H 2 O ( = 5, 6, 7, and 7.5)).…”

Thermochemistry of aksaite

“…(2,7) All the reagents were analytical grade (Beijing Chemical Factory, P.R.C. The solid was separated, washed thoroughly with distilled water, and then with alcohol and ether.…”

“…Aksaite, (1,2) MgB 6 O 10 · 5H 2 O, is a magnesium borate mineral with a structural formula of MgB 6 O 7 (OH) 6 · 2H 2 O and is found in several places in the world. Until now, there have been no reports on the thermodynamic properties of aksaite.…”

Synthesis and Thermodynamic Properties of Magnesium Borates

“…On the base of literatures [10,11], Jia et al [12] reported a modified synthesized method of aksaite (MgO•3B 2 O 3 •5H 2 O). A brief procedure was to use MgO, which was obtained by thermal decomposition of Mg(OH) 2 •4MgCO 3 •6H 2 O in an electric furnace at T=873 K for about 3 h, H 3 BO 3 , MgCl 2 •6H 2 O, and H 2 O (mass ratio= 1: 9.3: 50: 12.5) were transferred to a flask with a reflux condenser at the boiling temperature of 395.15 K and became a clear solution.…”

“…The thermodynamic properties of magnesium borates mentioned were given in Table 2. 9,10,13]. [17] reported the thermodynamic properties of the aqueous ternary system (MgB 4 O 7 -MgSO 4 -H 2 O) at 298.15 K using isopiestic method, and qualified based on Pitzer ion-interaction model.…”