The effects of Cu2+adsorption on surface dissolution of albite

Interactions between feldspar minerals and aqueous solution are essential processes of element migration and gathering near the earth's surface. In this paper, coupling relationship between surface dissolution of albite and Cu2+ adsorption in various solutions is investigated. The release amounts of Si, Al and Na from albite are all lowest at pH 5 and increase with increasing or decreasing pH. The larger Al/Si ratios than 0.33 at pH 1 and 2 can be attributed to the formation of surface coatings that resemble a silica gel, also including the easier release of Al than Si in acidic solutions. According to XPS and EPR analysis, Cu2+& nbsp;ions are chemically adsorbed on albite surface to form inner-sphere type Cu(II) surface complexes at pH 5. Significantly, the adsorption of Cu2+& nbsp;ions could promote the releases of Si, Al and Na from the surface of albite to a certain extent. The promotion mechanism can be interpreted as the adsorbed Cu2+& nbsp;ions bring more bound H2O molecules getting to albite surface, resulting in the easier hydrolysis of Si-O-Si and Si-O-Al bonds. While, the final destination of Cu2+& nbsp;ions regulated by the dissolution of albite should be further investigated in next stage work.

Automated summary

This paper investigates the coupling relationship between surface dissolution of albite and Cu2+ adsorption, and finds that Cu2+ adsorption can promote the release of elements from the surface of albite.