Study On Preparation Of High Purity And High Activity Magnesium Oxide From Microcrystalline Magnesite In Sichuan And Tibet And Its Adsorption Properties For Lead Ions

In recent years,the modern industrial industry has continued to develop.The industrial wastewater generated during the production process cannot be properly treated,which has brought irreversible harm to human health and directly threatened human survival and development.As a kind of treatment agent for industrial wastewater that has gradually risen in recent years,active magnesium oxide has received more and more attention and research.However,at present,various types of active magnesium oxide obtained through a simple magnesite calcination process still have problems such as low product quality and rough processing methods.This not only caused a huge waste of resources,but also brought severe challenges to the sustainable development of China's mineral resources.This article uses the characteristics of the low content of impurities Fe,Al,Ca,and Si in the microcrystalline magnesite in the LeiWuqi region of Tibet,China,to explore and optimize the product development and application of this type of magnesite,to develop high purity and highly active magnesium oxide.At the same time,based on this product,the adsorption performance of simulated lead-containing industrial wastewater was studied.The research contents include:mineral properties of microcrystalline magnesite;high-purity Mg?OH?₂ is obtained by using light-burned magnesia of calcined ore product as raw material,and changing the amount of hydrating agent NH₄Cl,hydration temperature,stirring time,and solid-liquid ratio,and chemical composition of the hydration product,hydration rate?calcinated by holding at 1100?for 2h?,XRD and micro-morphology analysis to optimize the hydration process;high-purity Mg?OH?₂precursor was used to prepare active magnesium oxide,and the calcination temperature and holding time were Influence of activity and micro-morphology;The effect of solution pH,adsorption time,reaction temperature,and addition amount of magnesium oxide on Pb²⁺removal rate and Pb²⁺concentration of simulated lead-containing industrial wastewater was studied using high-purity and high-activity magnesium oxide as the adsorbent.Based on the above research,the microcrystalline magnesite in Sichuan-Tibet region is determined in this article.The purity is as high as 47.56%and the quality is extremely high.It is more suitable for the development of high-quality magnesium chemical products.The optimal process conditions are:0.75%NH₄Cl addition,75minutes of stirring time,solid-liquid ratio of 1:15.Under these conditions,the hydration rate can reach 94.56%;hydration under the optimal process the MgO content of the product obtained after impurity removal is less than 99%?w?after burning reduction?soaking at1100?for 2h?,which indicates that the light-burnt powder of this type of microcrystalline magnesite can be hydrated to remove impurities to prepare extremely pure hydroxide.The best process for preparing highly active magnesium oxide from high-purity Mg?OH?₂ is:calcination at 600?for 3h,the iodine value activity and citric acid activity of magnesium oxide reach 220.93mg I₂/gMgO and 8.21s,respectively,with excellent quality and long activity index super chemical industry standards,the best conditions for the adsorption of high purity and high activity magnesium oxide are:pH=6,adsorption time 30min,reaction temperature 75?,the amount of magnesium oxide added 3.5g,the minimum concentration of Pb²⁺after adsorption reaches 64.17mg/L,for Pb²⁺the maximum removal rate reached 93.88%,which provided a new direction for the future development and research of magnesite in the Sichuan-Tibet region.