Research On Construction Technology And Quality Control Of Manganese Slag Subgrade Based On Environmental Protection

Chinese electrolytic manganese production occupies the first place in the world,is an important strategic resource in China.Electrolytic manganese slag is the remaining acid leaching waste during the production of electrolytic manganese.With the development of electrolytic manganese industry,the amount of electrolytic manganese slag is increasing,which not only requires a large amount of land for stacking,but also the heavy metal elements and ammonia nitrogen in the manganese slag will enter the surrounding water environment,causing serious ecological environmental pollution.Guizhou province is the core industrial area of manganese resources in China.The surge in the amount of manganese slag has become a serious problem limiting the development of the local industry and endangering public health.Therefore,it is imperative to study the environmental protection methods of massive consumption of manganese slag.This paper studies the solidification technology of manganese slag and the method applied in embankment filling,in order to effectively consume manganese slag in large quantities.The main research is as follows:Through the study of the particle size of electrolytic manganese residue analysis,determination of moisture content test,liquid plastic limit,XRF,XRD,SEM test analysis of the basic physical and chemical properties,the results show that the specific gravity of 3.04,electrolytic manganese slag is greater than the general clay,main oxides including SiO₂、SiO₃、Ca O、Al₂O₃、Fe₂O₃、MnO、MgO and K₂O,p H is 5.6,not dry manganese slag moisture content of 32.7%.Through leaching toxicity analysis,the main pollutants in manganese slag are manganese ion and ammonia nitrogen,of which the content of manganese ion is 1097.713 mg·L^-1,548 times higher than the standard value of the Integrated Wastewater Disdischarge Standard（GB8978-1996）,and the content of ammonia nitrogen is 595.010 mg·L^-1,23 times higher than the standard value,which belongs to theⅡindustrial solid waste.The solidification test results showed that the pollutants in the manganese slag decreased with the increase of the content of quicklime.When the content was 10%,the manganese ion concentration was 9.069μg·L^-1and the ammonia nitrogen concentration was 11.67 mg·L^-1,all lower than the standard limit.The leaching concentration of ammonia nitrogen first decreases and then increases with the increase of water content.When the leaching concentration is the lowest,the water content is25%.Combined with the compaction test,it is known that the best water content of solidified manganese slag should be 23%.The engineering characteristics of 10%quicklime solidified manganese slag were studied by load-bearing ratio test,triaxial test,strength meter method and penetration test,etc.,and the CBR value was determined to be 68%,the effective stress strength parameter cohesion c=57.11k Pa,internal friction The angleφ=19.82°,the modulus of resilience is between 153.8MPa～188.5MPa,the strength is good,meets the specification requirements,the permeability coefficient is1.38×10^-5cm/s,and the pollutants are not easy to be groundwater Leaching,the column leaching test shows that the leaching amounts of manganese ion and ammonia nitrogen are less than the standard limit.According to the geotechnical parameters obtained from the laboratory test,PLAXIS finite element software was used to simulate and analyze the slope stability and stress and strain of the solidified manganese slag embankment.It was found that the maximum settlement value of the embankment was 129.4mm and the safety factor of stability was 1.84,which met the standard requirements and could effectively resist the settlement deformation.By manganese slag embankment construction technology for research,from the perspective of environmental protection,the construction technology,environmental protection measures,the construction quality and environmental quality,etc were analyzed,and the obtained manganese slag embankment construction,the method of part of manganese slag plant mixed method is put forward and fresh manganese slag"improved plant mixed approach",provide a reference for using manganese slag after road.