Olivine Mineral

Olivine is a mineral that contains a mixture of forsterite (more than 90%) and fayalite in solid solution with beneficial properties such as a high melting point, high density and high magnesium content.

Olivine is used in the following fields

Iron-Steel Industry: Today, most important field of usage of olivine is iron-steel industry.


Use as an abrasive

In many countries Olivine is used to clean surfaces of buildings and bridges. For this purpose, olivine is sprayed by pressurized air to clean dirt, rust and similar unwanted material on surfaces. Air pressurized powder olivine is also used to obtain smooth or uneven surfaces or to cut any part of a building or decor. Before 1988, this was done by silica sand but it was prohibited because of its harm to health and olivine began to be used as it does not contain free silica.

 

Cast Industry

Essentially, cast industry used mostly quartz sand. But in troubled cases between mold and casted metallic material, molds made from olivine are preferred. When casting, quartz sand react with metal while olivine has no reaction with metal. As silica sand causes low melting temperature and so steel sinters on sand, only molds made from olivine are used particularly in manganese steel casting. For this reason first burns and then holes will form on surface of steel. But olivine does not generate any low temperature with manganese steel. In cast production, chrome and zircon may be added in small ratios to olivine sand at times.


Advantages of olivine in cast industry against silica sand are as follows:


  • Rather low and uniform dilatation against temperature. Thus less failures caused by dilatation.
  • Because of low dilatation temperature bentonit and 3% water will be sufficient as binder
  • Constant resistance against thermal choc
  • Can be easily shaped
  • Formation of olivine from partly angled particles cause more extensive green strength
  • Silica sand causes to silicosis disease as for olivine has no such an effect
  • During process, olivine calcines easily and takes small amount of water in its structure so reuse would be easy


Refractory Industry

Forsterite brick production from olivine has been in progress because of high fusion degree of olivine. Refractory degree of forsterite bricks is about 1890° C.


Blast furnaces in iron-steel industry, cement sector and many furnaces requiring high temperature are using these bricks as internal bricks. They are also used to produce many refractory material.


Olivine is also used to cover inner side of pots. Olivine is not so resistant against slag in blast furnaces containing high CaO so is generally used in less hot and base parts of blast furnaces. Steel material containing olivine gets cool more quickly.


Using as a ballast material

Because of its high density, olivine is used in fields where balance function is essential. Petroleum platforms in North Sea use olivine to balance platform. Olivine fill pores of concrete of platform and assist to balance function by its weight.


Olivine pebbles are used in railways in order to ensure a strong and balanced base. Relatively angular and sound pebbles ensure a good drainage and prevent railway to slip.