Reduction of Chromium Oxide from Slag by Silicon and Magnesium
In metallurgy and chemical engineering, the reduction of chromium oxide from slag is a process in which metal compounds are removed from a given slag. This process involves mixing molten metal and silicon or magnesium, then melting the slag with a burner, and lastly separating the metal compounds from the slag with a filtering system. The purpose of this short paper is to illustrate and explain the reduction of chromium oxide from slag by silicon and magnesium.
Chromium is both a metal and a non-metal, and is the only elemental metal to possess the characteristics of both. Chromium oxide, therefore, is the result of combining chromium with oxygen and is a glossy black powder that is water insoluble. The chromium oxide in slag is not a useful additive and must be removed through the reduction process.
The use of silicon and magnesium to reduce chromium oxide from slag is beneficial due to their lower melting points. Silicon, when heated in air, melts and vaporizes at 1414°C. Magnesium, on the other hand, melts and vaporizes at 640°C. These comparatively low temperatures optimize process efficiency and minimize energy consumption compared to the reduction of chromium oxide from slag with other metals.
The actual reduction of chromium oxide from slag with silicon and magnesium consists of three steps. First, a molten metal and silicon or magnesium is mixed and melted with a burner in a refractory lined container. This creates an environment for the reduction of chromium oxide from slag. Secondly, a filtering system is used to separate the metal compounds from the slag, producing a slag rich in chromium oxide but depleted of useful metal compounds. Lastly, the slag rich in chromium oxide is then treated in an acid attack to remove any residual chromium oxide.
The reduction of chromium oxide from slag using silicon and magnesium is a simple and cost effective process that can be conducted with relative ease. It requires little to no energy input and produces minimal environmental impact. More importantly, it is the most efficient and economical way to remove chromium oxide from slag, yielding a slag that is rich in chromium oxide but depleted of useful metal compounds. The process is both simple and safe and can quickly and effectively reduce chromium oxide from slag.
