Usually the alkali decomposition conditions for wolframite are: alkali concentration of 500 g / L, the base amount of the theoretical amount of 160, reaction time of 4h, each batch of wolframite 1 t. In the various process conditions of alkali decomposition, such as temperature, time and alkali concentration, the temperature has the greatest impact on the leaching rate of tin. In normal decomposition conditions, tin leaching rate increased with temperature increasing and the increase rate is much faster than the increase rate of tungsten leaching rate, the reason of which is the leaching reaction of tin is more inclined to thermodynamically controlled than tungsten. So the production often needs making a balance between the decomposition rate of tungsten requirements and product quality requirements of different minerals to determine the optimum reaction temperature. At this temperature, the low leaching degree of tin and high leaching rate of  tungsten achieves the best combination.

 

However, this detinning process is mainly carried out at high temperatures (160 ~ 170 ℃), because temperature changes have little effect on the leaching rate of tin at low decomposition temperature. Thus, for the atmospheric mechanical agitation leaching process of caustic soda, because the temperature is low (only 105 ~ 110 ℃), this detinning process is not meaningful then.