The massive amount of sodium silicate in the used sand was a pollution source, especially in the waste water from the wet reclamation of used sand. A new process of wet reclamation by biologically treating the waste w...The massive amount of sodium silicate in the used sand was a pollution source, especially in the waste water from the wet reclamation of used sand. A new process of wet reclamation by biologically treating the waste water produced during the wet reclamation process of used sand was studied in the paper. In the work, the precultivation of N. palea was performed firstly, and three different scrubbing solutions： （1） tap water, （2） modified medium for N. palea, and （3） filtrate of the broth treated by N. palea for 15 days, were used. The results of the primary investigation show that a de-skinning ratio of 90% is obtained when using the scrubbing solution containing modified medium for N. palea at the ratio 1：2 of sand and scrubbing solution, and the maximal concentrations of Na^＋ and SiO3^2- are 1.49 g.L-1 and 0.51 g.L-1, respectively. The results of the optimal biomass, pH value decrease and Na^＋ and SiO32 consumption indicate the optimal incubation conditions are at the irradiance of 5,000 lux and 25 ℃. Using the filtrate of the broth treated by N. palea for 15 days as the scrubbing solution directly, a de-skinning ratio of 93% is the highest compared to the results of the tap water and the modified medium for N. palea. In the biological process using N. palea, less water is used and little wastewater is produced, which is advantageous to the purpose of green manufacturing and environmental protection.展开更多
Inorganic binder used in casting process has the advantages of low odor,labor-friendly conditions,and relatively low cost,which is one of the main development directions for casting molding materials in the future.How...Inorganic binder used in casting process has the advantages of low odor,labor-friendly conditions,and relatively low cost,which is one of the main development directions for casting molding materials in the future.However,compared to organic binders(such as resin binders),inorganic binders exhibit lower bonding strength and are more sensitive to environmental humidity.This sensitivity poses challenges,particularly in the reclamation of used sand,thus limiting their broader application.In this paper,the research and application status of inorganic binders(mainly silicate inorganic binders)and their curing methods are summarized.In addition,the research and application of phosphate inorganic binders and 3D printing inorganic binders that are being developed are introduced.Meanwhile,a detailed comparative analysis is conducted on the challenging issue of“reclamation for used sand”in the application of inorganic binders.Finally,the development direction of inorganic binders is clarified.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51075163)the Research Fund for the Doctoral Program of Higher Education of China (No.20100142110017)
文摘The massive amount of sodium silicate in the used sand was a pollution source, especially in the waste water from the wet reclamation of used sand. A new process of wet reclamation by biologically treating the waste water produced during the wet reclamation process of used sand was studied in the paper. In the work, the precultivation of N. palea was performed firstly, and three different scrubbing solutions： （1） tap water, （2） modified medium for N. palea, and （3） filtrate of the broth treated by N. palea for 15 days, were used. The results of the primary investigation show that a de-skinning ratio of 90% is obtained when using the scrubbing solution containing modified medium for N. palea at the ratio 1：2 of sand and scrubbing solution, and the maximal concentrations of Na^＋ and SiO3^2- are 1.49 g.L-1 and 0.51 g.L-1, respectively. The results of the optimal biomass, pH value decrease and Na^＋ and SiO32 consumption indicate the optimal incubation conditions are at the irradiance of 5,000 lux and 25 ℃. Using the filtrate of the broth treated by N. palea for 15 days as the scrubbing solution directly, a de-skinning ratio of 93% is the highest compared to the results of the tap water and the modified medium for N. palea. In the biological process using N. palea, less water is used and little wastewater is produced, which is advantageous to the purpose of green manufacturing and environmental protection.
基金supported by the National Natural Science Foundation of China(Nos.52275334,52205361,51075163,and 50575085).
文摘Inorganic binder used in casting process has the advantages of low odor,labor-friendly conditions,and relatively low cost,which is one of the main development directions for casting molding materials in the future.However,compared to organic binders(such as resin binders),inorganic binders exhibit lower bonding strength and are more sensitive to environmental humidity.This sensitivity poses challenges,particularly in the reclamation of used sand,thus limiting their broader application.In this paper,the research and application status of inorganic binders(mainly silicate inorganic binders)and their curing methods are summarized.In addition,the research and application of phosphate inorganic binders and 3D printing inorganic binders that are being developed are introduced.Meanwhile,a detailed comparative analysis is conducted on the challenging issue of“reclamation for used sand”in the application of inorganic binders.Finally,the development direction of inorganic binders is clarified.
