Low Cost Treatment of Tungsten Waste

Tungsten containing waste is complex, difficult to extract and complicated. This kind of APT is manufactured by traditional methods with long process flow, narrow range of raw materials, large investment in equipment, unstable products and poor economic benefits. In recent years, people have made some explorations in the preparation of ammonium parotungstate from waste materials containing tungsten and achieved some results.

Some scholars have published a method of recovering ammonium partrungstate from waste containing tungsten. The main contents are as follows:

1. Mixed the raw material and sodium carbonate by the ratio of 1:0.6 to the weight ratio and sintered at 700 centigrade temperature in the reflecting furnace for 2 hours in the melting or semi melting state, and the caking is made out. The water leaching: first, the cooled sintered materials are Gran with water in the ball mill, and then the slurry is pumped into the iron trough to ensure the tungsten content in the solution. The ratio of 30g/L is added to the boiling water for 1 hours, and the filter, washing and filtrate are filtered and washed with the plate frame pressure filter to enter the next program; the lotion is returned to the grinding section to be used as grinding water and leaching water, and the filter cake is treated separately according to the valuable elements.

2. The leaching filtrate is pumped into the drums, heated and stirred with 2N sulfuric acid to adjust the pH to 9.5, adding 20 liters of saturated ammonium chloride and Magnesium Sulfate solution per m³ material liquid, stirring for 1.5 hours, using 2N sulphuric acid for pH to 8, boiling for 30 minutes, statically for 4 hours, and filtering and washing with a plate frame filter, except filtrate into the next program. The washing liquid is returned to the grinding section to be used for grinding water and leaching water. The filter cake is processed separately according to the valuable elements.

3.In the dechroming bucket of the filtered filtrate, heated and stirred and heated to 40, the sodium sulfide was added by 2 times the content of molybdenum and chromium. The pH value was adjusted to 8-10 by 2N sulfuric acid, and heated to the boiling point for 1.5 hours. The filter was filtered by the plate frame filter, and the filtrate entered the next program, and the cake was sold to chromate plant as chromium residue.

The above recovery method has a wide range of preparation methods, with the exception of simple procedure, short process, high yield of tungsten, stable quality of tungsten, good physical and chemical properties, small investment in equipment and low production cost with acid extraction of tungsten waste to produce ammonium paratungstate.

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