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.

In this industry branch, olivine is used as dispersant and slag regulator in blast furnaces. Irregular iron stone and coke are used in blast furnaces to produce steel. But these row materials are not sufficiently pure. Thus row material put in blast furnace must adequately be melted and mixed to slag.

As solvent, olivine has an important role in fusion necessary in first step. Adding olivine increases MgO value and consequently viscosity of slag. High MgO value of olivine brings in action slag viscosity independently from composition of materials in blast furnace. This is another advantage.

Besides, olivine has an important assistance to sintering. Namely, using olivine in sinter facilities decreases sintering degree and so coking coal consumption also decrease and capacity increase due to increase of sinter’s stiffness. This process also ensurehomogenous dispersion of iron minerals in furnace and so impurities will remove from environment more easily.

Another characteristic of olivine is to prevent alkalis in furnace come together.

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.

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

Using 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.

Using as an Electric heater: These heaters are called “Night Storage Heaters”. Bricks made of olivine designed like a radiator absorb and store temperature and heat houses by emitting temperature especially during daytime.

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.