KrollVerfahren

The KrollVerfahren, also known as the Kroll process, is a method for producing magnesium metal. It was developed by William Kroll in the late 1930s and is a significant advancement in metallurgy. The process involves the high-temperature reduction of magnesium chloride with calcium.

The core of the KrollVerfahren is a two-step reaction. First, molten magnesium chloride (MgCl2) is reacted with molten calcium metal (Ca) in a vacuum furnace at temperatures around 1100-1200 degrees Celsius. This reaction yields magnesium vapor and calcium chloride (CaCl2). The chemical equation for this step is: MgCl2 (l) + Ca (l) → Mg (g) + CaCl2 (l).

The magnesium vapor is then condensed into solid magnesium metal. The calcium chloride byproduct can be recycled or used in other industrial applications. This process is crucial because it allows for the production of high-purity magnesium, which is essential for various industries, including aerospace, automotive, and electronics.

Before the KrollVerfahren, magnesium was primarily produced using electrolytic methods, which were more energy-intensive and produced a less pure product. The Kroll process offered a more economical and efficient way to obtain magnesium, especially for high-demand applications. The success of the KrollVerfahren also paved the way for the development of similar processes for producing other reactive metals like titanium and zirconium.