| With the development of modern industrial technology, concentrations of Ni2+、Cu2+ and other heavy metal ions in water are accumulating which exceed the self-purification capacity of water bodies, water pollution has become increasingly severe. As an adsorbent to remove the heavy metal ions, mineral materials have the merits such as large adsorption capacity, good removal effects, lower cost, simple operation process and equipment, easy recycling. Maifanite is a kind of silicate rock class complex mineral which is nontoxic and harmless. It has a certain adsorptive property since the silicate-based chemical composition and the porous structure. However, the adsorptive performance of Maifanite can be affected by Maifanite composition, structure, morphology and other factors.To this end, the paper used XRF、ICP-OES、XRD、SEM、laser particle analyzer to analyze Maifanite chemical composition, structure and morphology; Maifanite dosage, the initial concentration of heavy metal ions solution, static contact adsorption time were designed as the orthogonal experiments to explore the effect on the unmodified Maifanite adsorption properties of Ni2+、Cu2+ in water; Size modification, acidation modification, calcification modification and thermal modification were carried out to discuss the effect of parameters such as particles, H2SO4 concentration, dosage, processing time, Ca Cl2 concentration, dosage, processing time, and heating temperature, time on the adsorption properties of Ni2+、Cu2+ in water. This provides a thinking and method to further improve the purification effect of Maifanite on heavy metal ions pollution water.The main conclusions of this paper are as follows:1. The main chemical components and contents of Maifanite were: w(Si O2)=69.70%、w(Al2O3)=18.07%、w(Na2O)=6.06%、w(K2O)=2.52% and w(Ca O)=2.12%. Main mineral phases of Maifanite were quartz and calcium-albite. Maifanite had porous structure. Small particle sizes and pore structures characteristics of Maifanite were suitable as water purification adsorbent material.2. When Maifanite dosage was 20 g, Ni2+、Cu2+ initial concentration was 50 mg/L, static adsorption time was 24 h, the Ni2+、Cu2+ adsorption rates by unmodified Maifanite were best as 64.20% and 67.12% respectively.3. In the size modified part, Ni2+、Cu2+ adsorption rates were highest at 200 meshes as 78.97%, 81.05% among the 40~200 meshes.4. H2SO4 concentration was 2.5 mol/L, H2SO4 dosage was 50 m L, acidation processing time was 0.5 h, the adsorption rates of Ni2+、Cu2+ by acidation modified Maifanite were 83.94%, 86.87%.5. Among the experiments of calcification modified Maifanite preparation and the adsorption property study, Ca Cl2 solution concentration was 2.5 mol/L, Ca Cl2 dosage was 180 m L, calcification processing time was 2.5 h, the Ni2+、Cu2+ adsorption rates were respectively as 86.85%, 88.01%.6. Study on adsorption of thermal modified Maifanite, under optimal conditions as 250 ℃, 2 h, the modified Maifanite showed better adsorption performance to Ni2+、Cu2+ in water as 91.07% and 92.31%.7. Parallel contrast studies had been done on Maifanite adsorption rates of three kinds of chemical modifications. The results revealed that, the best adsorption rates reached 91.07%, 92.31% when the absorbent was thermal modified Maifanite. Compared the Ni2+、Cu2+ adsorption rates between unmodified and thermal modified Maifanite, the modified ones increased by 41.85% and 37.53%. |
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