Feldspar is the most abundant group of minerals in the Earth’s crust. Their use in industrial applications is widespread. In fact, feldspar can be found in a great many objects we use on a daily basis!
Half the Earth’s crust
Feldspar is the name given to a group of naturally occurring alumino-silicate minerals containing varying amounts of potassium, sodium, calcium, and/or lithium. The feldspar group of minerals is by far the most abundant group of minerals in the Earth’s crust, making up about 50% of all rocks. Feldspar minerals are essential components in igneous, metamorphic, and sedimentary rocks, to such an extent that the classification of a number of rocks is based on their feldspar content.
Although highly present in igneous rocks like granite, commercial feldspar is generally mined from pegmatite or feldspathic sand deposits.
Feldspars are generally divided into three categories, feldspar, pegmatite and feldspathic sand, and are primarily used in industrial applications for their alumina and alkali content. Feldspars and pegmatites play an important role as fluxing agents in ceramics and glass production, and are valuable functional fillers in the paint and adhesive industries.
Feldspar is a tectosilicate with the chemical composition
KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8
Physical properties
- High alumina and alkali content
- High potassium content
- Low iron content
- Chemical inertness
- pH stable
- Consistent hardness (6-6.5 on Mohs scale)
Glass and ceramics lead the way
In glassmaking, Multi Mineral Processing feldspars are excellent fluxing agents for flat and container glass, as well as for insulation wools. Feldspar is an excellent source of alumina which improves end product hardness, durability, and resistance to chemical corrosion.
Used in ceramics, feldspar and pegmatite are the main vitrifying or fluxing agents used during the firing process of ceramic bodies. Fluxes melt at an early stage in the firing process forming a glassy matrix that bonds the other components of the system together, ensuring the durability of fired bodies. Multi Mineral Processing feldspars contain low levels of coloured oxides, so they are particularly prized for white tiles and sanitaryware production.
Fine-milled Multi Mineral Processing feldspars are valuable multi-functional fillers and extenders in applications such as paints for their good dispersibility, chemical inertness, stable pH, high resistance to abrasion, and low viscosity.
Multi Mineral Processing has a wide portfolio of feldspar and pegmatite products. With in-depth knowledge of how feldspar interacts in our customers’ end products, we will continue to harness our minerals to help customers improve performance, reduce costs and minimize their carbon footprint.