How to Recovery Tungsten and Tin Metals from Waste Ammonium Paratungstate

At present, the recycling of tungsten resources mainly focuses on tungsten-containing alloy waste and tungsten-containing catalyst waste. Ammonium paratungstate waste contains a lot of sediment, and its acid-base solubility is poor. The chemical recovery method is used to recover and utilize the environment, which is polluted greatly, the equipment is corroded seriously and the cost is high. Therefore, although there are many studies on ammonium paratungstate waste recycling, most of them are still in the laboratory pilot study stage. Recently, some scholars have published a method to recover tungsten and tin from waste. The process includes these steps:

(1)Grinding 80 meshes of APT waste by ball mill;

(2)The grinded material is classified by a round sieve, and the material with more than 80 meshes is returned to the ball mill for grinding, and the material with less than 80 meshes enters the next process.

(3)The classified 1000 g ore sample is evenly added into the feeding trough within 30 minutes, the working parameters of the shaker are selected, the flushing water and the inclination angle of the bed surface are adjusted, so that the distribution of the material on the bed surface is sector-shaped, and the feeding device is adjusted to receive the products separately. After the separation process, stop the machine, keep flushing water, clean the bed surface, and classify the remaining particles on the bed into the product; select low-grade coarse concentrate.

(4)The selected low-grade coarse concentrate is grinded by a bar mill to less than 120 meshes for screening, and the materials with more than 120 meshes are returned to the bar mill for further grinding, and the materials with less than 120 meshes enter the next process.

(5)Magnetic minerals such as iron sand are separated from materials less than 120 mesh by wet magnetic separator, and non-magnetic minerals such as tungsten-tin minerals, gold, silver and copper are also separated for the next flotation process.

(6)The separated tungsten-tin-rich minerals were added to the flotation tank at a liquid-solid ratio of 3:1, adjusted PH value to 3 with sulfuric acid, and then xanthate 900g/T, No. 2 oil 400g/T and sodium silicate 800g/T were added in turn. The sulfide ore and high tin-tungsten minerals are separated by stirring for 1 hour. The sulfide ore is used to recover other metals and the high tin-tungsten minerals are used as raw materials for the next process.

(7)Put the high-grade tin-tungsten minerals selected in step (6) into the groove shaker, and further select the high-grade tin-tungsten minerals with a stroke of 15m/m, a stroke of 240 rpm and a longitudinal slope of 0.1 degree for the next step.

(8)Put the high-grade high-stannum tungsten obtained by step (7) into the flotation tank with a liquid-solid ratio of 4:1, adjust PH to 8, then put sodium sulfide 420 g/T, No. 2 oil 500 g/T, sodium silicate 700 g/T, 733 paraffin oxide soap flotation agent 300 g/T, stirring for 1 hour, the Scheelite Concentrate and tin concentrate can be obtained by flotation.

This technology is easy to control and easy to operate. It is not as difficult to realize as other APT waste recycling processes. Its production cost is low, wastewater can be recycled, and it is environmentally friendly. It is a technology of reducing, harmless and resourceful APT waste. It has remarkable economic, social and ecological benefits.

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