Extraction of Sodium Tungstate from Tungsten Ore by Pyrometallurgical Smelting

Tungsten is one of the strategic metals produced from tungsten ores through sodium tungstate. The hydrometallurgical process is a common technology for extracting sodium tungstate from high-grade tungsten concentrates. The grade of tungsten ore is decreasing, and the mineral processing to produce a high-grade concentrate suitable for the hydrometallurgical process is becoming more difficult. It is desirable to develop a new technology to effectively recover tungsten from the complex low-grade tungsten ores. A fundamental study on the pyrometallurgical processing of wolframite was carried out through thermodynamic calculations and high-temperature experiments. The wolframite was reacted with Na2CO3 and SiO2 at 1050-1200 degrees C and then leached with water to obtain a sodium tungstate solution as a feed for the traditional process of APT (Ammonium paratungstate). The factors affecting the extraction rate of tungsten from wolframite were investigated in air and neutral atmosphere. The extraction rate of tungsten was found to increase with increasing Na2O content and decrease with increasing SiO2 addition and temperature. The extraction rate in argon was higher than that in air for wolframite.

Automated summary

Tungsten is extracted from tungsten ores using a hydrometallurgical process. However, as the grade of tungsten ore decreases, it has become more challenging to produce high-grade concentrates suitable for this process. Therefore, a new technology for recovering tungsten from low-grade ores is desired. A study on pyrometallurgical processing of wolframite was conducted, where it was reacted with Na2CO3 and SiO2 and then leached to obtain a sodium tungstate solution. Factors affecting the extraction rate of tungsten were investigated, with Na2O content, SiO2 addition, and temperature being found to influence the rate.