Study On Dolomite Heating By Microwave And Magnesium Metal Preparing

Magnesium and magnesium alloy as new application materials have been widely used in military, civilian and other areas in recent years. In China ,Magnesium industry have developed rapidly in recent years, and currently Pidgeon process is the main process of producing magnesium in China. Although Pidgeon process is a relatively mature technology, but from the perspective of recycling economy and sustainable development facts, there are still some problems exist, which restrict the further development of the process. It mainly reveal in three areas: environment pollution, destruction of resources and labor intensity. This is runs against to the current concept of "clean production", "Optimization of production", so it is necessary to study corresponding improvement measures according to the problem that traditional crafts cause. Microwave technology combines with the traditional method through controlling the relevant parameters, which can be a way to improve Pidgeon process.To achieve the purpose of saving energy and reducing consumption.Through heating dolomite which creates burnt dolomite by microwave technology, and analyzing the reduction process by Thermodynamics and Kinetics theory, we can find out the restrictive step of microwave heating and the relevant factors that impact reduction process. Accord to the conclusions design specific experiments.And through the result of reducing furnace heat balance, the microwave reduction way compared with traditional method, energy-saving 30-35%.In the microwave heating experiment, we used equipment M W-L0316V Longtech microwave oven and a high-precision infrared thermometer Ravtek to measure temperature. Compare with the traditional heating methods, the burning loss ratio and the rate of hydrate activity by microwave heating were studied. The results show that: the necessary technology to achieve a better quality of burnt dolomite, which represents burning loss ratio of 46.5 -47.5%, hydrate activity of 36 percent. Traditional heating temperature range is 1250-1300℃, and the heating time is 140-180 min; microwave heating temperature range is required for 1200-1240℃, the heating time is 100-130 min, which means 50-60℃lower than the traditional heating temperature and 40-50min time reduction.In the Magnesium reduction experiment, while adding burnt dolomite,ferrosililium and fluorite to vacuum reducing furnace under certain conditions, through controlling the reduction temperature, reducing time,charge fineness,briquette pressure system,different silicon content in feeding and magnesium price compare the price of ferrosilicon price, we can Find out the relations of these parameters with Reduction efficiency of magnesium and the availability of silicon, than determine the best parameter values. Experiments show that: In order to improve the efficiency of Reduction efficiency of magnesium, availability of silicon, and reduces the consumption of raw materials and lower production costs, the best of conditions and the control of gradient scope is reducing temperature1175-1200℃; recovery time by 7-8h, increasing the ball can appropriately extend the time. Ball pressure (working pressure):150-160kg / cm2, (referring to burden fineness of 100% 100 mesh); mixture silicon ratio: M = 1.1-1.15, when Magnesium Price: Ferrosilicon prices> 3.0, M is close to 1.2. When Magnesium Price: Ferrosilicon prices< 3.0 M is close to 1.0.