(Institute of Mineral Materials and Applications, Southwest University of Science and Technology, Mianyang 6210/0, Sichuan)
The project comes from the National Natural Science Foundation "Study on Interlayer Structure and Multi-body Self-assembly Mechanism of Vermiculite-bearing Minerals" (40 102006).
First, the content introduction
The samples used in this study were collected from industrial vermiculite in Yuli vermiculite mine, Xinjiang.
(I) Saturated adsorption of ammonium by industrial vermiculite
When the industrial vermiculite sample is saturated with ammonium, the exchangeable cations between layers are released, and the total number of exchangeable cations released is consistent with the total number of adsorbed ammonium ions. This shows that the adsorption of ammonium by samples is almost all ion exchange adsorption. The main factor that determines the saturated adsorption capacity of ammonium by industrial vermiculite is the content of vermiculite crystal layer in the sample structure.
(2) Adsorption of heavy metal ions (Cu2+, Pb2+, Zn2+) by industrial vermiculite.
The results show that industrial vermiculite has strong adsorption capacity for ammonium ions and heavy metal ions, and its adsorption capacity is positively correlated with the content of vermiculite crystal layer in the structure. At low concentration, the adsorption of metal ions Cu2++, Pb2 ++ and Zn2 ++ belongs to ion exchange adsorption, and the adsorption equilibrium can be reached within 30 ~ 60 min. The pH value of the solution and the concentration of ions in the solution have great influence on the adsorption capacity. At high concentration, the ion exchange adsorption of heavy metal ions reaches saturation, mainly physical adsorption.
Second, popularization and application
Vermiculite has excellent cation exchange performance and adsorption performance, and has important applications in agriculture, horticulture, environmental protection, construction and other fields. Vermiculite is one of the nonmetallic minerals with good resource prospects and potential advantages in China. Because the vermiculite industry in China does not pay enough attention to the development of new products and uses of vermiculite, the application of vermiculite in China is more limited to light thermal insulation materials. Facing the fierce competition of increasing thermal insulation materials, the development of vermiculite industry has been seriously affected.
In the aspect of environmental protection, the treatment and reuse of industrial sewage has become an increasingly important topic for human beings. At present, many works have been done at home and abroad to treat heavy metal ion wastewater by using the ion exchange adsorption characteristics of natural mineral rocks (including vermiculite), but most of them are in the laboratory research stage. For industrial vermiculite, the main reason for adsorption is cation exchange, which is determined by vermiculite crystal layer and its properties in industrial vermiculite. The research results provide a theoretical basis for the application of vermiculite in the treatment of wastewater containing ammonium and heavy metal ions.
Three. Identification, awards and patents
200 1 won the third prize of scientific and technological progress in Sichuan province.