Alumina (Al2O3) is an intermediate raw material generated during the production of aluminum from bauxite ore. Processing parameters such as particle size, Al2O3 polymorphs, or impurities have a direct impact on the use of energy and chemicals during refining and smelting and therefore affect both the efficiency and profitability of the process.
Particle size directly affects the rate of alumina dissolution in the electrolytic baths in the smelter. Furthermore, fines present an issue for both health and safety and product transport. On-line particle-size analysis during the production of alumina has increased throughput by 50%, and achieved payback within 12 months by avoiding the need to reprocess ‘out of spec’ material.
Knowledge of the different Al2O3 modifications is vital in predicting and optimizing its behavior during the smelting process. γ-Al2O3 is the desired polymorph for electrolysis, as it dissolves more easily during the smelting process than α-Al2O3. For this reason, the ratio of the different polymorphs of alumina must be monitored with X-ray diffraction (XRD).
The drive for sustainable metal manufacturing and increased ESG requirements make fast and accurate impurity monitoring mandatory in liquors and red mud. Our X-ray fluorescence solutions allow elemental analysis in real-time, during the process and in the laboratory. XRD instruments can monitor the phase composition of red mud, which ensures compliance with safety and environmental standards.
Production of aluminum from purified alumina by electrolysis (the Hall-Héroult process) requires an immense amount of electrical energy. Continuous monitoring of the bath composition is of paramount importance in determining, adjusting, and maintaining optimal conditions, which result in significant cost and energy savings when successfully carried out.
X-ray diffraction (XRD) makes it possible to monitor electrolytic bath composition, as well as quickly and accurately predict the relevant process parameters of different types of electrolytic baths (with the addition of Ca, Mg, Li, and K). The method calculates bath ratio along with excess AlF3 and CaF2, as well as free alumina content and liquidus temperature.
The respective lifetime of carbon anodes, that are required and consumed during aluminium smelting, are mainly controlled by the average crystallite size (Lc) of the graphite platelets, as well as particle size and contaminations. XRD is a standard method (ASTM D5178) for the determination of crystallite size, and is implemented in Malvern Panalytical’s solution for electrolytic bath analysis.
To ensure frequent and safe analysis, Malvern Panalytical offers completely automated laboratory solutions, including sample preparation tailored to the specific needs of each aluminum smelter.
Aluminum metal and its alloys can be found everywhere in our daily life; in cars, cans, smartphones, and airplanes. To guarantee high-quality standards of alloyed or coated aluminum, permanent control of composition and impurities is mandatory for manufacturers – whether the aluminum is produced from primary raw materials or recycled material.
Our high-throughput analytical solutions based on XRF technology allow the monitoring of aluminum metals and alloys and can be automated and adapted to each manufacturing process. XRD can also check metal properties such as stress and texture to avoid out-of-spec metals production.