Yield control index of southern China's ionic-adsorption rare earth based on information entropy

Yield quotas of ionic rare earth rationed by Chinese government from 2006 has played an important role in guiding rare earth productivity in China. The ionic rare earth yield quotas are analyzed in six provinces in Southern China to demonstrate the yield changes by adopting information entropy theory. The results show that the quotas have experienced stages of "stability-growth-stability". The information entropy, equilibrium degree and dominance degree changed gradually from 2006 to 2008. However, from 2008 to 2011, the information entropy and equilibrium degree rose rapidly, while the dominance degree fell fast. And then from 2011 to 2014, the information entropy, equilibrium degree and dominance degree returned to the steady stage. Researching results on factors affecting on quotas show that the control management implementation provided orientation for quota determination. Rare earth concentrate price fluctuation tendency has been consistent with information entropy variation between 2006 and 2011. After 2012, rare earth price fell dramatically with steady mining quota. The reserve-production ratios are in conformity with information entropy curve in three stages. The relationship between production quotas and influencing factors are discussed by describing the changes of the quotas from the point of information entropy, which has great significance to grasp the change trend of production quotas.