Application Intermediate Medium Calorimetry To Study The Microwave Energy Absorption Ability Of Solid Materials

The application of microwave heating is based on whether interact between solid materials and microwave and how strong it is. Formula (P=2πfε0ε"E2), used to calculate the absorbing ability of materials by previous, need the basic datais such as the dielectric constant of the material, the electric field intensity and atc., which are difficult to get for the factors of particle size, purity, temperature of the materials. So it is hard to use the theoretical formulas to predict the microwave absorbing ability of solid materials. In addition, it is the same hard to reflect the true state of material temperature by using the thermometer to directly measure the temperature of the materials in the microwave field, and there is high requirements on the thermometer. Therefore, in this thesis, we try to study the microwave absorption capacity of the solid materials using a new method name Intermediate Medium Calorimetry and it provide the basis for the rational application of microwave heating technology.Intermediate Medium Calorimetry, testing the temperature of medium material (water) to calculate the power absorbed by different materials, is invented by the Guangxi University, and has got the national invention patent. In this thesis, we have study the absorbing microwave capacity about24kinds of solid materials and the law of the impact of the relevant factors. The main conclusions can be drawn as follows:(1) Intermediate Medium Calorimetry is easy and convenient to operate, and is not affected by shape, size, mass of materials. So the method can be easily used in testing the microwave energy absorbing of difference minerals.(2) The optimal operation conditions of the testing method are that water can be used as the medium to absorb microwave with addition mass of500-600g; the microwave heating time should be less than240s; the microwave vessel material is suggested to use high purity quartz; and repeat test is recommended to improve its reliability and representativeness.(3) There is no obvious relationship between the absorbing ablility of the materials and their categories, color of mineral, the metal cation, and the quantity of water of crystallization. Therefore, it is difficult to predict the absorbing ablility of the materials only according to these properties.(4) In the discussed materials, copper oxide and manganese dioxide show the strong absorption, followed by manganese sulfate, and silica does not absorb microwave. For the concentrate sample, lead concentrate show the strongest in absorbing microwave, weakest for zinc concentrate.(4) In the testing range of microwave irradiation time and microwave power output, which show small effect on absorption of material; mixing the materials do not affect on their individual microwave absorbing ability, but for the strong absorption of material, the increasing of material mass will change energy distribution absorbed between water and material.