Question

The common impurities present in bauxite are:
A. \[F{e_2}{O_3},Si{O_2}\]
B. \[NaCl,MgC{l_2}\]
C. \[AlC{l_3},MgC{l_2}\]
D. \[CaC{l_2},MgC{l_2}\]

Answer 1

Hint: Bauxite is a rock formed from a reddish clay material called laterite soil and is most commonly found in tropical or subtropical regions. Bauxite consists primarily of aluminum oxide compounds (alumina), silica, iron oxides, and titanium dioxide.

Complete step by step answer:
The major impurities in Bauxite are iron oxides (goethite & hematite), silicon dioxide, the clay mineral kaolinite as well as small amounts of anatase. Consequently, its composition varies considerably with alumina constituting from about 50% to about 70%.
Bauxite ore is the world’s primary source of aluminum. The ore must first be chemically processed to produce alumina (aluminum oxide). Alumina is then smelted using an electrolysis process to produce pure aluminum metal. Bauxite is typically found in topsoil located in various tropical and subtropical regions. The ore is acquired through environmentally responsible strip-mining operations.
Bauxite has a number of impurities in it including iron oxides (hematite and goethite), \[F{e_2}{O_3}\] the sand silicon dioxide \[Si{O_2}\] the clay mineral kaolinite and small amount of \[Ti{O_2}\] known as anatase.

So, the correct answer is Option A.

Note: Impurities are removed from bauxite by leaching a bauxite ore using a leach solution to dissolve impurities from the bauxite ore and form a pregnant leach solution containing the impurities in solution, removing the leached bauxite ore from the pregnant leach solution using a solid-liquid separation process to produce a clarified pregnant leach solution, and concentrating the clarified pregnant leach solution to recover a recycle stream including water for recycling to the leaching process. In addition, the concentrated leach solution can be subjected to an impurity removal process to recover purified leach solution for recycling to the leaching process.