Zinc Borate Chemical Garden and Zinc Borate Powders from Tincal Mineral and Zinc Sulfate Heptahydrate

The formation of the first membrane, swelling crystal by incoming water from semipermeable membrane and irregular shaped branches were observed optical microscopy, when zinc sulfate heptahydrate crystals immersed in saturated borax solution. powders obtained mixing dilute aqueous solutions had B, O, Na, S Zn elements. Presence Na 1/2B4O7.xH2O was indicated EDX analysis. molar ratio B 2O3/ZnO around 2. FTIR analysis absorbance values asymmetric stretching vibrations B(3)-O at 1351 cm-1 to that (4)-O 1026 increased with their heating time 90ºC during preparation. X-ray diffraction patterns presence Zn(OH)2 4(OH)6(SO4)·4H2O. borate compounds not crystalline since no sharp peaks related borates present x-ray diagram. There two mass loss steps TG curves powders. step 150-350ºC second 700-950ºC due elimination decomposition ions respectively. submicron a mixture borate, Zn(OH)2, Zn4(OH)6(SO4)·4H2O they could be used as lubricant additive small particle size 600 nm.