Sulfuric Acid-Phosphoric Acid Mixed System to Treat Wolframite

At present, the main method of industrial decomposition of tungsten minerals is the NaOH decomposition process. This method must be used in extreme conditions (high temperature and high alkali) to realize the effective decomposition of tungsten ore. However, the acid decomposition method of tungsten ores has a very high thermodynamic reaction trend, but the decomposition is often incomplete due to the limitation of kinetics.

Some scholars have provided a method for extracting tungsten from wolframite raw materials. In the process of grinding wolframite, calcium containing calcium containing material is added, and the ore material obtained after reaction is decomposed by sulfuric acid and phosphoric acid mixed acid system. The main process is as follows:

The wolframite concentrate with a particle size of less than 250 m (containing WO₃ 71.3%) and apatite (containing P₂O₅ 35.81%) are added to the ball milling tank after being batching, and the ball milling reaction is 2h after the liquid and solid ratio 0.5:1mL/g is added to the water. After the reaction is terminated, the tungsten ore is filtered to dry 24h.

At 80 ℃, the mixed acid solution with H₂SO₄ concentration of 250g/L and H₃PO₄ concentration of 300g/L is used to extract 4h, the ratio of liquid to solid is 10:1mL/g, and the leaching rate of tungsten is 99.2%. After the filtrate is extracted by the tertiary amine based extractant, the mother solution is filled with the loss of sulphuric acid and returns to a new round of leaching. Under this decomposition condition, the leaching rate of tungsten is 99.1%.

The wolframite concentrate (including WO₃71.3%) with a particle size less than 250 m and apatite (including P₂O₅35.81%) is added to the ball grinding tank and is added to the ball milling tank after adding the liquid to solid ratio 0.5:1mL/g to 2H. After the reaction is terminated, the tungsten ore is filtered and dried by 24h and analyzed by X ray diffraction.

At 80 ℃, the mixed acid solution with H₂SO₄ concentration of 250g/L and H₃PO₄ concentration of 300g/L is used to extract 4h, the ratio of liquid to solid is 10:1mL/g, and the leaching rate of tungsten is 99.2%. After extraction of tungsten by tertiary amine extractant, mother liquor is added to the spent sulfuric acid to return to the new round of leaching. Under the same decomposition conditions, the leaching rate of tungsten is 99.1%.

This method has realized the high efficient decomposition of wolframite and wolframite at normal temperature and atmospheric pressure. It breaks through the limitation that the sulphuric acid phosphoric acid mixed acid system can not deal with the wolframite and the mixture of wolframite. The calcium containing substance is widely used, the price is low, and the phosphoric acid is generated during the decomposition. It can be used to make up the phosphoric acid consumed in the decomposition process. The circulation process of the leaching agent can only be supplemented with sulfuric acid to the initial level. The whole process is easy to operate and easy to industrialize.

• < Prev
• Next >