Ammonia Decompose Scheelite Ore

Scheelite is the main raw material for tungsten smelting. The general method of smelting scheelite is pure alkali smelting. This method has a large amount of alkali and needs to be decomposed under the conditions of high temperature and high pressure. The pollutant discharge is serious, which is not conducive to the economic development of our country.

In view of the existing technology, a domestic scholar has put forward a method of ammonia decompose scheelite to the particle size of 0.01~0.05mm, adding ammonia water to a high-pressure reaction kettle, stirring speed of 1000~1200r.min-1, slowly heating up to 140~150°C, adding oxygen to 4~5h, cooling the temperature after the reaction is finished, when temperature is cooled and finished. When the degree reaches 30~50°C, the alkaline solution of the leaching residue and tungsten is obtained, and the alkaline solution of the tungsten is added to the alkaline solution of the tungsten, and the pH is 6~7. At 25~35°C, the D301 macroporous alkali anion exchange resin is added to the ion exchange 30~50min to obtain the D301 resin containing tungsten, the 40~50min is desorbed with 10%~14%'s ammonia water and the resin is then desorbed and then the resin is finished again to get ammonium tungstate solution. This method is implemented as follows:

The shattered scheelite was grinded to a particle size of 0.03mm, the ammonia water was added to the autoclave with a concentration of 13% ammonia in a high pressure reactor. The addition of ammonia was 5 times the weight of the scheelite and the stirring speed was 1100r.min-1, and the oxygen was slowly heated to 145°C, the oxygen partial pressure was 0.25Mpa, the reaction was 4h, the temperature was cooled, when the temperature reached 40°C. The alkaline solution of leaching residue and tungsten is obtained. The pH is 6.5 and the concentration of hydrochloric acid is 1mol/L in the alkaline solution of tungsten. At 30°C, the D301 macroporous base anion exchange resin is added to the ion exchange 40min to obtain the D301 resin containing tungsten, 45min with 13% ammonia water, the volume ratio of the ammonia to the D301 resin is 4:1. After desorption, the resin was regenerated and ammonium tungstate solution was obtained. The concentration of ammonium tungstate is 52.8 g/L, and the desorption rate of tungsten is 99.9%.

Compared with the existing technology, the ammonia decomposition scheelite adopts the extraction method of atmospheric pressure, normal temperature, low corrosion and high decomposition efficiency, simplifies the operation, saves the cost, overcomes the traditional method of extracting pure alkali in the process, and uses ammonia water to extract not only clean and subsequent pollution.

• < Prev
• Next >