Question

Which one of the following minerals is contained in the monazite sands?
1. Oil
2. Uranium
3. Thorium
4. Coal

Answer 1

Hint:
Monazite is found in the placer deposits, and it is rich in monazite. The large deposits of monazite sands are found in India, Madagascar, and South Africa. Monazite sand does not have oil and coal.

Complete answer:
The Monazite sand constitutes the Earth’s rare metals, which occurs in the earth’s crust in an isolated crystal format.

The monazite sand is radioactive, and it contains a high amount of thorium, which is used for geological study. The rich ore contains sand, and the ore of thorium is mainly extracted from the monazite sand.

From the monazite, thorium is extracted with a separation process. Sundaram estimates that Rs. 96,000 crores of monazite were illegally exported to the countries over a decade and by the private beach sand manufacturers.

Depending on the region, Monazite contains uranium of 0.2 to 0.4 percent in the form of uranium oxide, and it also contains 4.5 to 9.5 percent thorium as thorium oxide.

Thorium is a weak radioactive metallic chemical element, it is silvery, and when exposed to air, it tarnishes black. The thorium is an electropositive actinide and has a high melting point.

The thorium mineral sand is contained in the monazite sand.

Thus, option 3. Thorium is the correct answer.

Note:
In India, the sand is found in the coastal areas of Kerala and Tamil Nadu. India is the third-largest producer of monazite sand. For thorium, lanthanum, and cerium, monazite is an essential ore. In placer deposits, it is also found. Huge deposits of monazite sands occur in India, Madagascar, and South Africa. In India, the deposits are especially rich in monazite.