Analysis of electrolytic manganese slag characteristics and study of influencing factors in southwest China
More than half of the manganese producers in China are located in the southwest region,and the annual generation of tens of millions of tons of electrolytic manganese slag,mostly disposed of by damming and stockpiling,poses a great threat to the environment.In this paper,characterization and leaching toxicity experiments are conducted on the electrolytic manganese slag from southwest China.The basic physical properties such as water content,pH of leachate,soluble salt content and particle size are first determined from the collected electrolytic manganese slag,and then X-ray fluorescence spectrometry(XRF),X-ray powder diffractometer(XRD),scanning electron microscopy(SEM)and inductively coupled plasma mass spectrometry(ICP-MS)are used to analyze the chemical composition,phase composition,microscopic morphology and leaching toxicity of manganese slag.The research results show that the maximum difference between the average mass water content of new and old manganese slag of different enterprises is more than 19％,and the highest difference of leachate pH is 0.95 and 1.45 respectively.In addition,the soluble salt content of fresh manganese slag can reach up to 15.15％,and the index of soluble salt content needs to be paid attention to in the environmentally friendly treatment.The main chemical components in manganese slag were SO3,SiO2,CaO,Fe2O3 and Al2O3,with average mass fractions of 20.55％,13.69％,16.06％,14.88％and 4.93％in all samples,respectively.In addition,the main mineral phases in the manganese slag were gypsum,quartz,mica,microplagioclase,chlorite,burnt gypsum and pyrite,etc.The characteristic peaks of gypsum and quartz in the old and new manganese slags of enterprise C and enterprise E show opposite trends during the stockpiling process influenced by the stockpiling conditions,and the characteristic peaks of gypsum and quartz in the manganese slag of enterprise C are enhanced during the stockpiling process,but enterprise E is weakened.Besides,the leaching toxicity characteristics of manganese slag show that the leaching concentrations of Mn2+and NH4+-N both decrease continuously during the process of stockpiling,but the concentrations of Mn2+and NH4+-N in the leaching solution of historical manganese slag still exceed the limits of GB/T 8978-1996 primary emission standards by 65.92-935.00 times and 2.56-63.80 times,and the long-term stockpiling still has a large risk of environmental pollution in long-term storage.The purpose of this study is to provide data support for the treatment and disposal of electrolytic manganese slag in China.
environmental engineeringelectrolytic manganese slagharmless treatmentresource utilizationphysical and chemical propertiesleaching toxicity
NETL
NSTL
万方数据
维普
