Investigating the method of tungsten leaching from hydrocracking catalyst HC-102 W/Ni/Al2O3/SiO2

Abstract

This study investigates the process of extracting tungsten from used hydrocracking catalyst (specifically model 102-HC W/Ni/Al2O3, SiO2), and provides valuable insights into the efficient recycling of tungsten from secondary sources. Tungsten samples are isolated with sodium hydroxide(NaOH, caustic soda or lye) and then analyzed using X-ray fluorescence (XRF) methods. The main components of the sample are lithium-aluminum-tungsten-oxide (LiAIW2O4), nickel-molybdenum oxide (NiMoO4), tungsten oxide (WO3), and silicon oxide (SiO2). The experimental design focuses on parameters such as roasting temperature, roasting time, pulp density, leaching temperature, and leaching time during the sample preparation and leaching operation. The time and temperature of roasting have a combined effect on tungsten extraction, with temperature being the main factor. Increasing the pulp density reduces tungsten extraction, and longer leaching time with sodium hydroxide improves tungsten recovery. Under the conditions of roasting temperature 800 °C, roasting time 120 min, pulp density 10 %, leaching temperature 70 °C, and leaching time 60 min, the tungsten dissolution recovery rate is 92.3 %.

Keywords

• Resource management
• Recycling of tungsten
• Leaching
• Hydrocracking catalyst
• Sodium hydroxide