Study Of The Calcination Of Magnesite Process With The Environment-protecting And Energy-Saving

The topic chosen four kinds of low-grade magnesite as experimental material, analysis of mineral composition and microstructure of the magnesite by using XRD? SEM and other means of detection, study on the decomposition process of magnesite. Through a series of experiments show that the thermal of magnesite complete decomposition smaller than the theory, there is no direct relationship with mineral crystal form that apparent porosity and density is inversely proportional to the volume of magnesite.Magnesite decomposition related to internal impurities, the more impurities, the worse the degree of development of magnesite crystals, the lower the decomposition temperature and intensity.The simulation to three section of the rotary kiln calcination, investigation magnesite crystal,taste and impurities have an effect on activity of light burned magnesium, to determine the optimum process parameters of rotary kiln calcined magnesite. The results show that using rotary kiln three calcined low-grade magnesite and the calcination temperature at 700?, periclase grains is the minimum and activity is the best. The blowout, powder, activity and strength of fine grain magnesite is better than coarse-grained magnesite, more suitable for calcining rotary kiln burning. As harmful impurity,serpentine should be avoided in calcining light burning powder, in calcination process, the dehydration of serpentine generate M2S and MS, MS and MgO reaction generate M2S, resulting in MgO content decreased, the activity was reduced.Effect of calcination temperature on the activity of magnesite by using citric acid and hydration. With XRD and SEM observation phase composition and microstructure after burning. The effects of relationship between periclase grain size and activity, using orthogonal experiment improved hydration, shorten the test time.Through the research found that four kinds of minerals MgCO3 grain did not decomposition completely at 600?, there is mother salt illusion, magnesite decomposition completely at 700-800?, the crystal structure and grade of magnesite had no effect on preferred orientation for the growth of periclase grain, the periclase grain is the smallest when the calcination temperature of 700?, the grain gradually merge and grow with the temperature increases, there is a clear contour and grain boundaries at 1000?. Periclase grain size depends on the calcination temperatureand no relationship with magnesite crystal. Through orthogonal optimization of hydration and determine the test conditions for 20 ml of distilled water,MgO quality of 1.0g, hydration time 2 h, to use new methods was standard,for average relative error is +1.16%, less than±3.00% that magnesium industry standard has been stated, fully meet the experimental error requirements of building materials industry, provide the reference data revision of industry standards in the future.