What are the properties of calcium carbonate and its uses

What are the properties of calcium carbonate is question that you may ask yourself. Calcium carbonate, or limestone, is a mineral and a soft mineral at that. It can be white, brown, green or even black. The majority of chalk used in construction was once limestone since it becomes hard when mixed with water and it can also be found in things like tusks from elephants. In fact the word chalk comes from the name of the area where this substance was first discovered by miners who were looking for lead ore close to Dorking, England back in 1790. Chalk has many properties, like thermal insulation and acid-resistance as well as sometimes being made into an abrasive material for sharpening knives or scouring surfaces with ease.

Physical properties of calcium carbonate

1. Physical hardness

Curling up your hand and placing it on a piece of chalk will demonstrate the hardness of calcium carbonate. It is a soft mineral that is used when a harder surface is needed but one that might be damaged by say a rock or brick.

2. Cleavage and fracture properties

Chalk does not have cleavage properties, meaning it does not break evenly along any lines or planes that would allow it to break into multiple pieces as a softer mineral would. Instead, this mineral breaks along planes formed by the crystal structure of calcium carbonate but it does so in a conchoidal pattern, meaning like the inside of an eggshell. This means that, although the material itself is soft it can still be broken into pieces by a sharp object.

3. Crystal structure

The calcium carbonate crystal structure has many cubic faces, meaning all the plane surfaces are cubes or hexagons. This makes it strong and gives it the ability to break into many pieces if broken carefully.

4. Heat resistance

The hardness of calcium carbonate allows it to endure heat without quickly melting or softening under temperatures of more than 700℃. This means that limestone can be used for things like scouring pots and pans and this is actually one of the main uses for chalk nowadays.

5. Ice resistance

The hardness of calcium carbonate makes it able to survive temperatures of more than 800℃ for as long as half an hour. This makes it useful for things like making ice blocks in a refrigerator to keep food cold.

6. Thermal conductivity

Chalk is a very good thermal conductor, meaning it can transmit heat quickly across them easily. This means that the temperature in a room hanging around 70°F or 25℃ will be raised by 40 ℃ (104 °F or 38℃) if the air temperature is 75°F or 24℃ and this will create a room temperature of 88°F (31℃).

7. Thermal expansion coefficient

Chalk has a thermal expansion coefficient low enough to make it useful for the construction of things like kilns. The coefficient is 0.00015, meaning that for every degree Celsius rise in temperature the size of the material will increase by 0.000015 cm or 0.006 inches.

8. Abrasion resistance

Chalk can be made into a fine abrasive that is used to sharpen knives and other tools that may need sharpening. It is also used to give surfaces a smooth surface like scouring pads and scrubbing pads that are used to wash dirt and grease off surfaces.

Uses of calcium carbonate

1. Abrasive

CaCO₃ can be used as an abrasive for sharpening knives, scissors and other tools. It is actually soft enough to use on human skin as a remedy for cuts and scrapes and it can even be used to exfoliate skin to remove dead skin cells. This helps to answer the question; what are the properties of calcium carbonate.

2. Antacid

Some people still believe that the use of chalk to treat indigestion is a true remedy but this is not the case. The reason this remedy has been widely believed in the past is because it was once recommended by one of the top doctors of his time, Dr. Benjamin Ward Richardson. The truth is that chalk does not do anything to help indigestion and it certainly does not stop diarrhea. In fact, chalk can cause indigestion by creating a lower pH in the stomach because it lowers the intestinal pH and this makes food absorption more difficult. It can also make diarrhoea worse by taking in water and creating a jelly like substance that blocks the intestines.

3. Household item

Chalk is used today as a mild abrasive cleaner or even as a cosmetic product, especially to remove stains on clothes. It is also used to mark turf fields during sports games but this use has decreased in recent times.

In conclusions, what are the properties of calcium carbonate, can be answered that calcium carbonate is a soft mineral. It is also a mineral that is used in many different ways even though it is not very strong or hard. Curling your hand on a piece of chalk will demonstrate the softness of this material but it can be made into an abrasive used to sharpen knives and stones, and made in to scouring pads to wash surfaces clean.