Research on Polluting Characteristic of Tungsten Residue from Ammonium Paratungstate (APT)

The tungsten residue from 14 ammonium paratungstate (APT) industries was sampled, the total concentrations of heavy metals in the residue and the leaching concentrations were respectively analyzed by Solid Waste-extraction Procedure for Leaching Toxicity-sulphuric Acid & Nitric Acid Method (HJ/T 299-2007) and appendix S of Identification Standards for Hazardous Wastes-identification for Extraction Toxicity (GB 5085.3-2007), and the polluting characteristics of the tungsten residue defined. The results show that the total concentrations of heavy metals of tungsten residue are in accordance with the normal distribution, and Cu, Zn and As have relatively high concentrations, with maximum value of 6 260, 25 000 and 26 900mg/kg, and mean value of 3 510, 4 560 and 5 640 mg/kg respectively. On other hand, the leaching concentrations of Pb, As and Hg are higher than others, with maximum value of 33.6, 26.2 and 0.85 mg/L, which are 6.72, 5.24, 8.5 times higher than the standard values stipulated by GB 5085.3-2007, and the exceeding standard rate is 14.3%, 21.4% and 42.9% respectively. Tungsten residue is attributed to hazardous waste, whose featured pollutants are As, Mo and Hg.