Tungsten and molybdenum are the traditional superior resources of China. With the increasing consumption and continuous development and utilization of high quality tungsten and molybdenum resources, complex ore of lower grade and impurity has to been dealt with. It increases the difficulty of the beneficiation and metallurgy from the processing of raw material, especially for some similar elements, such as tungsten and molybdenum separation. On the other hand, with the rapid development of science and technology, the user puts forward higher requirements on the product purity. The traditional eliminating molybdenum method not only has the problems of long process, heavy pollution, high tungsten loss and higher cost, but also the molybdenum content has a narrow range in material liquid. And the depth of molybdenum also can not meet the new requirements. In recent years, rising of molecular design has gone deep into the chemistry, molecular engineering, chemical industry, medicine, mineral processing and other fields. People have gone deep from the macroscopic field of material into the substance of the microscopic world. With the aid of computer molecular structure to design intelligent system and the computer simulation and other modern means of science and technology, people have been able to compound a certain properties of special reagent which is used to solve specific practical problems. Although there are some properties differences between tungsten and molybdenum, these differences are not very clear. Simple use of these tiny differences is difficult to separate tungsten and molybdenum deeply and efficiently. Therefore, the study on the efficient and economic method of eliminating molybdenum from sodium tungstate solution deeply becomes a major topic in the study of tungsten metallurgy.

 

Next, let’s have a look at several effective eliminating molybdenum methods proved through a large number of experiments. First of all, let's take a look at the first approach - selective precipitation of eliminating molybdenum from sodium tungstate solution. 

1. On the basis of predecessors' successful experience, it starts from the specific system of tungsten smelting process and quantum chemistry, structure chemistry, molecular design theory. According to the nature differences of tungsten and molybdenum compounds, after a lot of analysis and research, selective precipitator M1152a has been made successfully from Na2W04 and (NH4) 2 WO4 solution to eliminate molybdenum.  

2. These reagents have a strong affinity to molybdenum in tungstate solution. It can make molybdenum form the stable and refractory compounds precipitation under simple and mild conditions. It hardly militates with tungsten of solution so as to realize the effective depth separation of tungsten and molybdenum. 

3. In the experiment process, we need to pay attention to the influence on eliminating molybdenum which is had by precipitation agent type, the precipitation agent dosage. In order to guarantee the good molybdenum effect, the reagent cost should be reduced as far as possible at the same time. For M1152a, the eliminating molybdenum agent dosage is advisable in 3-4 times the amount of theory. 

4. Finally, consider the rate of tungsten recovery in the process of eliminating the molybdenum from sodium tungstate solution to choose the most effective precipitation.