Hebei Messi Biology Co., Ltd. hydromagnesite of Tibet Bango Lake is white needle-like, plate-like, about 0.2-0.5 cm long, often constituting radial set of crystals. Single crystals extend along the C-axis, (010) the deconstruction is complete. Calculated specific gravity (according to D = (n-1)/K) is 2.313. Converted to Eagle’s hardness of 4 after measurement with microhardness tester. It is difficult to carry out crystallographic studies because of the small size of the crystals and their structural and tectonic limitations.
Microscopically it is plate-like, colorless, with predominantly positive extension, biaxial crystalline ortho-luminescence, Ng=1.544±0.002, Nm=1.527±0.002, Np=1.526±0.002, Ng-Np=0.018, (+)2v=78°–90°, parallel extinction. It is essentially similar to the optical constants of the mineral contained in the literature, except that no bicrystals are seen, and also the ductility is different. The absence of bicrystals is not only seen by us, but is also characteristic of hydromagnesite from the Caucasus, Western Tuva, and Tora in the USSR.
As early as the fifties, people have noticed that in the top of the lake sediment layer in Bangor, often sandwiched with a layer of white chemical sediment. Most scholars believe that it is a kind of calcium precipitation formed before the demise of the lake, due to the shallow lake water, calcium concentration in the water increases. Since chemical deposits in lakes can often indicate the characteristics of regional paleogeographic environments, in recent years, we have carried out in-depth microanalysis of this white chemical deposit to understand its main components and the formation environment, in order to further reveal the evolutionary history of hydromagnesite.
Hydromagnesite is a kind of natural alkali carbonate mineral with abundant reserves, which was first discovered in the late 1950s in areas such as Lake Bango in Tibet. China has now proved the hydromagnesite resource content of more than 100 million tons, is a rare large-scale deposits, mainly distributed in the northern Tibet salt lake area and some salt lake area in Qinghai. hydromagnesite pure texture, white color, “snow-white” or “white-flower” called, its chemical formula is 4MgCO-Mg (OH)-4H2O, in which the content of CaO and other impurities is low, the impact on the general application is very small, is the preparation of flame retardant, active magnesium oxide, heavy magnesium alkali carbonate, nano-magnesium hydroxide and other magnesium products such as high-quality raw materials of minerals. However, due to the limitation of geographical, transportation and other factors, it has not been better developed and utilized, and the research on the preparation of nano-magnesium oxide with different characteristics from hydromagnesite has not been reported.
Hebei Messi Biology Co., Ltd. used hydromagnesite of Lake Bangor in Tibet as raw material, and adopted the process route of “calcination, hydration and calcination” to prepare magnesium oxide with different characteristics. The effects of different calcination temperatures and times on the morphology, crystallinity, grain size and specific surface area of magnesium oxide and the effects of the second “hydration + calcination” on the morphology of magnesium oxide were investigated.
Hebei Messi Biology Co., Ltd. prepared magnesium oxide nanoparticles with different morphologies by controlling the calcination temperature and time under the simple process route of “calcination-hydration-calcination” using natural magnesite from Bango Lake, Tibet, without adding any reagent in the experimental process. The effects of different calcination temperatures and times on the morphology, crystallinity, grain size and specific surface area of MgO were investigated. The products were characterized by TGDTG, BET, XRD, SEM and TEM. The results showed that the increase of temperature or the extension of calcination time could help to improve the crystallinity of MgO, promote the crystal growth and reduce the specific surface area. Calcined at 650℃ for 1h, mesoporous reticulated magnesium oxide with specific surface area as high as 188.3m2/g can be obtained; calcined at 850℃ for 4h, rod-like and dumbbell-like magnesium oxide nanoparticles can be obtained, and flaky magnesium oxide nanoparticles can be obtained from mesoporous reticulated magnesium oxide with high specific surface area by “hydration+calcination” again.
Nano magnesium oxide (MgO) is a new type of highly functional fine inorganic materials, due to the nanomaterials of the surface effect, volume effect, quantum size effect and macroscopic quantum tunneling effect and other special effects, and has a number of different from the body of the light, heat, electricity, magnetism, mechanical and chemical properties. In recent years, it has important applications in the fields of antimicrobial agents, catalysts, adsorbents, advanced ceramics, optoelectronic materials, refractory materials, fillers, medicine and so on. Nano magnesium oxide usually has different morphological features, and different morphological features lead to different properties, and its main forms are powder, film, sheet, rod, tube, filament, etc., as well as some special morphology.