Method for recovering excess sodium hydroxide in tungsten smelting crude sodium tungstate solution

Abstract

The invention discloses a method for recovering excess sodium hydroxide in a tungsten smelting crude sodium tungstate solution. The method comprises the steps of mixing a tungsten ore raw material and water according to the volume ratio of 10: 3, then adding into a ball mill for ball milling to obtain tungsten ore slurry, adding a sodium hydroxide solution into the tungsten ore slurry to perform alkali autoclaving to obtain alkali autoclaved slurry, and performing pressure filtration on the alkali autoclaved slurry twice so as to obtain a crude sodium tungstate solution; pumping the crude sodium tungstate solution into a feeding and preheating device; enabling sodium tungstate crystal slurry obtained by separation after the well preheated crude sodium tungstate solution sequentially passes through a three-effect evaporation unit, a one-effect evaporation unit and a two-effect evaporation unit for evaporation and crystallization to enter a plate frame for pressure filtration so as to obtain a concentrated odium hydroxide solution and sodium tungstate crystals. The method disclosed by the invention has the advantages of high degree of automation, convenience in operation and capabilities of greatly reducing energy consumption, reducing later-stage wastewater neutralization control burden, reducing labor cost, reducing labor intensity and being easy to implement, and is in line with the national policies of reducing cost, increasing efficiency, saving energy and reducing emission.

Description

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AI Technical Summary

Benefits of technology

This technology uses triple-effect mixing flows for achieving efficient vapor condensations at very small temperatures without causing unwanted reactions or impurities from other materials being added into the system. By controlling these conditions, this technique allows for effective purification of solutions containing different chemical compounds such as calcium nitrate (CaN03) salt). Additionally, there are technical benefits like improved solubility, higher recoveries rates due to less volatile components remaining behind on solidified product surfaces compared to conventional methods, resulting in more consistently produced products over time.

Problems solved by technology

This patents describes methods for efficiently extracting valuable mettalcum (NaT) values from waste solutions containing rare earth elements like scandium (Sc), tantallium(Th2), niobium (Nioborus). These technical problem addressed in these inventions include efficient extraction without generating large amounts of water vapor during decompositioremediation operations due to its volatilizing characteristics at temperatures above 100°C while minimizing energy usage compared to other techniques.

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