Microwave Energy Applied Research In The Molybdenum Chemicals

Based on the summary of the present situation of the molybdenum chemicals (ammonium molybdate, molybdenum trioxide and sodium molybdate) and the application of the microwave energy on dryness , calcination and synthesis, the new application of microwave energy on drying ammonium molybdate, calcining ammonium molybdate to prepare for molybdenum trioxide and synthesizing sodium molybdate has been studied in this dissertation. A new technology preparing for molybdenum chemicals has been developed.The effect factors ,such as time, microwave power and green sample weight, and the technical conditions drying ammonium molybdate by microwave have been studied, the processing optimum conditions have been obtained by orthogonalized experiment. The optimum reaction conditions are that microwave power is 700W,time is 90 s, green sample weight is Sg.The results show that the dehydration ratio of ammonium molybdate can reach 100% under optimum reaction conditions .The results of this experiment indicate that the drying time of microwave method is 33 times as fast as that the traditional method. Dehydration and temperature models drying ammonium molybdate by microwave heating have been discussed. Due to the particularity by microwave heating, the mode of microwave heating is opposite to that of conventional heating. The grain cracks of ammonium molybdate has occurred by analyzing microstructure of production,these cracks are propitious to next calcination.The effect factors ,such as time, microwave power and green sample weight, and the technical conditions calcining ammonium molybdate by microwave have been studied, and the mechanism decomposing ammonium molybdate has been discussed. The processing optimum conditions have been obtained by orthogonalized experiment. The processing optimum conditions are that microwave power is 700W, calcining time is 8 min and green sample weight is 2g. Under the optimum conditions ,the decomposing ratio can reach 99.97%. The time of microwave calcination is only 1/10 of that of traditional method.The effect factors ,such as time, microwave power and green sample weight, and the technical conditions synthesizing sodium molybdate by microwave radialization have been studied , and the processing optimum conditions have been obtained byorthogonalized experiment. The processing optimum conditions are that microwavepower is 700W, synthesizing time is 20min and green sample weight is 5g. Under the optimum conditions ,the synthesizing ratio can reach 99.8%. The product was analyzed by X-ray diffraction, the results show that the product is sodium molybdate.The mechanism synthesizing sodium molybdate has been discussed.