| Magnesium smelting is an industry with high consumption of energy and heavy pollution. As the increasing international demand of metallic magnesium, China has become the largest manufacturer and exporter. Magnesium industry has brought good economic benefit, but the effect of the by-products in the smelting process on the environment should not be ignored. About six to seven tons of magnesium slag that can cause serious pollution will be made along with one ton of magnesium. The reasonable and effective treatments of magnesium slag which can realize the maximization economic benefit under the precondition of low environment pollution need to be solved.Coal resources are the main energy consumption pattern in China, which results in a lot of sulfur dioxide emissions and air pollution and acid rain that have seriously threaten the human living. Taking the path of sustainable development and energy saving and emission reduction, China uses lots of SO2 control technologies to reduce the harm of SO2. Setting up efficient, low cost and operationally reliable desulfurization facilities and using usual, high-efficiency desulfurizer are the effective approaches to make SO2 harmlessly treated.At the base of the previous research achievements, the thesis approximately simulates furnace spraying calcium in a home-made CFB reactor which is small style and in material fluidized thermal state. To the question of low magnesium slag desulfurization efficiency, adopting hydration and steam activation to activate magnesium residues and improve the pore structure can enhance desulfurization efficiency of magnesium slag.The temperature 950℃of the boiler and the furnace gas composition are simulated in the experiment.Desulfurization reaction experiments are made and the data of respective activation samples are analyzed and compared. It shows that the activated magnesium slag has significantly higher calcium utilization than the unactivated. Comparing hydration and steam activation, the latter is more effectiveness obvious.Metal magnesium slag is activated under condition of steam temperature 120℃, the calcium utilization is 39% at 90 minutes which is 15% higher than the unactivated calcium utilization and hydration activation calcium utilization is 33%.The experiment shows activation technologies have great effect on increasing magnesium slag calcium utilization. Because steam has a larger volume than water if they have the same quality, it is easier to connect with desulfurizer. Reducing water consumption is a feasible, simple, economic and promising activation technology in the event that activation effect is assured. Analytic comparisons are made about activated magnesium slag, unactivated magnesium slag, lack desulfurizer, specific surface area of different desulfurizers and pore volume through nitrogen adsorption automatic specific surface area analyzer. Experimental analysis indicate that the activation technologies change the pore configuration and improve specific surface area and pore volume of magnesium slag.As a result,calcium utilization are raised.The difference of desulfurization efficiency of desulfurizer grows mainly out of the difference of specific surface area and pore volume. Experimental determination:Magnesium slag specific surface area 1.725 m2/g, pore volume 0.002314 cm3/g, hydration activation magnesium slag specific surface area 1.83 m2/g, pore volume 0.008458 cm3/g, steam activation magnesium slag specific surface area 3.81m2/g, pore volume 0.0196068 cm3/g.Scanning electron microscope is used to scan the surfaces of the specimens from point to point. By comparing structures before and after magnesium slag activation sample, before and after desulfurization and before and after activated magnesium slag desulfurization, it is clear and direct to find the change of surface structure.The conclusions drawn by circulating fluidized bed desulfurization reaction, physical characteristics of magnesium slag contrast and micro observed by scanning electron microscope can be confirmed one another and a reasonable and effective treatment approach and a cheap efficient desulfurizer to control so2 discharge are found.
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