Cobalt and Tungsten Extraction from Diamond Core Drilling Crowns by Aqua Regia Leaching

• Published in: Materials Vol. 17; no. 21; p. 5179
• Main Authors: Dimitrijević, Stevan P., Dimitrijević, Silvana B., Veljković, Filip, Ivanović, Aleksandra, Petrović, Sanja J., Maletaškić, Jelena, Veličković, Suzana
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 24.10.2024
• Subjects: Acid leaching; Adsorption; Circular economy; Cobalt; Composite materials; Coring; Diamond drills; Drilling and boring; Efficiency; Energy consumption; Environmental conditions; Environmental impact; Field tests; hydrometallurgical process; Hydrometallurgy; Infrared imaging; infrared thermography; Leaching; Mass spectrometry; metal recovery; Nanomaterials; Nitric acid; non-destructive testing; Nondestructive testing; Oxidation; Precious metals; Raw materials; Recovery; Robotics; Solvent extraction processes; Steel production; Structural integrity; Sustainable development; Thermography; transition metals; Tungsten; Tungsten compounds; Waste materials; Zinc; Serbia
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma17215179

In this work, a hydrometallurgical process for the recycling of diamond core drilling crowns by means of aqua regia leaching and subsequent alkali leaching was investigated. This investigation continues a previous study in which nitric acid was used for the acid leaching phase. In the current study, higher tungsten recovery was achieved, reaching 98.2%, which is an improvement of about 1.5%. Another advancement of this study was the high Co recovery (97.21%) and the high purity of the tungsten trioxide obtained, comparable to the previously proposed technological process. Furthermore, a novel laboratory method for testing recycled diamond drilling crowns based on infrared thermography was introduced. Although this innovative approach is not the most accurate, it is fast and cost-effective and provides valuable results before the actual field test is conducted as a final evaluation. In addition, the infrared thermography method offers the advantage of non-destructive testing, ensuring that the diamond drilling crowns can be assessed without compromising their structural integrity. Other instrumental methods used to characterize the products and intermediates were X-ray diffraction (XRD), scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDS), and laser desorption ionization mass spectrometry (LDI-MS). The analytical method for the concentrations in all working solutions was ICP-AES.