The researchers used tungsten-containing waste to prepare ammonium paratungstate (APT) by leaching, extraction and ammonium sodium double salt method. Therefore, tungsten is effectively recovered. The quality of the prepared APT is higher. And it can further prepare tungsten oxide from APT. This method reduces the process cost by effectively recycling the salt-containing waste liquid generated in the process, which is worthy of vigorous promotion.
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A process for preparing ammonium paratungstate using tungsten-containing waste, including the following steps: 1. Raw material pretreatment; 2. Water leaching; 3. Impurity removal; 4. Heavy metal removal; 5. Molybdenum removal; 6. Acid extraction, evaporation and crystallization; 7. Double salt; 8. Conversion; 9. NaCl precipitation; 10. Precipitation of ammonium chloride; 11. Using the Hou's alkali method to prepare sodium carbonate and ammonium chloride from NaCl prepared in step 9, wherein, the sodium carbonate can be new_ed to step 1, and ammonium chloride can be new_ed to step 3, step 7 and step 8 for recycling.
