Abstract:
Wasted turquoises from Maanshan, Anhui Province, are treated and improved via thermochemical polymerization by hydrogen aluminium of phosphoric acid, which is similar to turquoise in chemical composition, and relevant auxiliary materials (such as congealment accelerator, activator, infiltrator, defoamer and dispersant) with different proportion. Environment scanning electron microscopy, X-ray powder diffraction, infrared absorption spectrum and full chemical analyses are employed to investigate by comparing the composition, crystal structure, mineral composition, surface feature, gemmological and mechanical properties of turquoises before and after thermochemical polymerization. The results indicate that thermochemical polymerization and thermochemical hardening help to enhance the technological and mechanical properties of wasted turquoise. Thermochemical polymerization facilitates dissolving and complexing of the grain border of turquoise crystallines to form flocculated structure without remarkable changes in chemical composition and crystal structure of the master turquoise, but with enhancement of the technological properties and increasing of mechanical strength of the material.