Effect Of Humic Acid Materials On The Solidification Of Mn In Electrolytic Manganese Slag And Its Control

With the rapid development of electrolytic manganese industry,the environmental problems caused by the stacking of electrolytic manganese slag are increasingly prominent.Rainfall leaching causes a large number of Mn to be transferred to the soil and water body,which seriously endangers human health.Therefore,the treatment of electrolytic manganese slag yard needs to be solved urgently.Its solidification and stabilization technology is the most economic and effective means at present.Therefore,to explore an effective method for Mn in electrolytic manganese slag It has important theoretical basis and practical significance to fix and reduce Mn.In this study,two kinds of humic acid materials,lignite and humic acid sodium,were selected as raw materials to prepare different modified and composite materials.Humic acid materials with better solidification efficiency for Mn in manganese slag were preliminarily selected,and the solidification mechanism was explored by combining characterization methods.Then,the adsorption characteristics of the materials and the regulation of Mn in manganese slag were further explored through adsorption experiments and pot experiments It can provide scientific basis for reducing pollutant migration and ecological restoration of storage yard.The main conclusions of this experiment are as follows:?1?The experimental results of the solidification efficiency of humic acid materials for Mn show that the solidification efficiency of lignite and humic acid sodium for Mn in manganese slag are 27.5%?31.5%and 7.2%?27.6%respectively,and the solidification ability of modified lignite and humic acid sodium for Mn in electrolytic manganese slag is only slightly improved,among which the solidification efficiency of insoluble humic acid for Mn in manganese slag is the most prominent,reaching 45.8%After compounding the selected insoluble humic acid,sulfonated humic acid sodium with chitosan and water-soluble phenol formaldehyde resin,the curing efficiency of chitosan insoluble humic acid composite and phenol formaldehyde resin sulfonated humic acid sodium composite to Mn in electrolytic manganese slag reached 55.7%and 73.1%respectively when the dosage was 10%.?2?Through SEM,elemental analysis,BET,FTIR and XRD characterization of humic acid materials,the results showed that:compared with the modified materials,chitosan insoluble humic acid composite and phenolic resin sulfonated humic acid sodium composite increased some holes,and the surface of the materials increased some convex structures,the specific surface area,average pore diameter,pore volume and so on were improved in different degrees,The specific surface area increased by56.8%and 122.0%respectively compared with that before modification,and the crystal structure was reorganized,the crystal position of Si O₂was changed,and some crystal structures such as Na₂CO₃,C₆₀,Na₂Si₂O₅,N₄H₄were added.According to the analysis of FTIR results,the curing mechanism of chitosan insoluble humic acid composite for part of Mn in manganese slag was due to the chemical chelation between oxygen-containing functional group and Mn cooperation.?3?The results show that the adsorption performance of phenolic resin sulfonated humic acid sodium composite is better than that of chitosan insoluble humic acid composite.When the p H is 5,the temperature is 20?,and the dosage of adsorbent is1g,the adsorption rate of Mn²⁺in the solution with 50ml Mn²⁺concentration of10mg/L is 2 hours,the adsorption characteristics of the adsorbent for Mn²⁺were in accordance with Freundlich adsorption model,the maximum saturated adsorption capacity was 13.486mg/g,and the adsorption process was multi-layer adsorption.?4?The results of pot experiment showed that:the curing efficiency of phenolic resin sulfonated humic acid sodium composite and chitosan insoluble humic acid composite was 62.6%and 79.6%on the 28th day after they were cured with 50%water content and electrolytic manganese slag.The results showed that the growth of ryegrass was significantly promoted by the improved EMR matrix,and the best content of chitosan insoluble humic acid composite was 5%.The plant germination rate,height and biomass of ryegrass increased by 182.6%,56.7%and 175.6%on the28th day compared with the blank control,and the content of Mn in the leachate decreased by 83.7%compared with the matrix of manganese slag,the average content decreased by 49.6%.To sum up,humic acid materials have good solidification effect on Mn in electrolytic manganese slag,have good inhibition effect on Mn leaching and migration in manganese slag,and are beneficial to plant growth,especially the chitosan insoluble humic acid composite materials show good control effect.The modified humic acid materials,as well as the composite materials prepared with chitosan and phenolic resin,can be applied to the electric field The ecological management of manganese slag yard.