Potassium Feldspar
Feldspar:
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.
Feldspars are potassium and aluminum salts, sodium and aluminum salts, and calcium and aluminum salts, respectively. Potassium aluminum silicates (KAlSi3O8), sodium aluminum silicates (NaAlSi3O8), and calcium aluminum silicates are the chemical names for feldspar (CaAl2Si2O8).
Feldspars tend to have a brittle to ductile transition in the 700 to 800 °C range – far lower than many of the materials with which they are mixed – and therefore it often behaves as a flux.
Chemical Specification:
| S.No | Components | Percentage | Presence |
|---|---|---|---|
| 1 | Silica (SIO2) | % | 66.06% |
| 2 | Iron (Fe2O3) | % | 0.07% |
| 3 | Aluminum ( Al2O3) | % | 17.32% |
| 4 | Calcium (CaO) | % | 1.21% |
| 5 | Magnesium (MgO) | % | 0.14% |
| 6 | Sodium (Na2O) | % | 2.99% |
| 7 | Potassium (K2O) | 11.61% | |
| 8 | Loss on Ignition (L.O.I) | % | 0.50% |
| Physical Properties | |||
| 9 | Whiteness | % | 58 |
| 10 | L Value | % | 78 |
| 11 | L Value | % | 78 |
| 12 | A Value | % | 2 |
| 13 | B Value | % | 4.5 |
| 14 | Shrinkage | % | 12.5 |
Potassium Feldspar (Grade - 2)
| S.No | Components | Percentage | Presence |
|---|---|---|---|
| 1 | SPotash (K2O) | % | 7.4 |
| 2 | Sodium (Na2O) | % | 4.1 |
| 3 | Calcium (Cao) | % | 0.65 |
| 4 | Aluminum Oxide (Al2O3) | % | - |
| 5 | Ferric Oxide (Fe2O3) | % | - |
| 6 | Silicon Oxide (SiO3) | % | - |
| 7 | Magnesium (MgO) | % | - |
| Physical Properties | |||
| 8 | Whiteness | % | 40.3 |
| 9 | L Value | % | 65.1 |
| 10 | A | % | 2.6 |
| 11 | B | % | 6.4 |
| 12 | Shrinkage | % | 12.5 |
INDUSTRIAL ADVANTAGES:
- Used as fluxing agents Ceramic Industries.
- Abrasives
- Enamel glazes
- Used as fluxing agents in Glass Industries.
- Fillers in the paint, rubber, adhesive and plastic industries.
- Porcelain
- Welding Electrodes.
- Includes floor tiles and shower basins bathrooms, glass for drinking water and other fluids, fiberglass used for insulation and different types of tableware
used for dishing meals.
Lumps:
Feldspar 100Mesh
Detailed Application of Feldspar:
The most important properties of feldspar to downstream industries and many other industries are their alumina and alkali content. For this reason, alkali feldspars (potassium feldspars) have a wide range of applications in paint industries, glass, and ceramic making industries. Here are some of the applications
of potassium feldspars.
Glass: Feldspar is a critical material in the production of glass. It is also a crucial raw material in its production as it tends to act as a fluxing catalyst. As a fluxing catalyst, it reduces the temperature of quartz while simultaneously helping to keep the viscosity of the produced glass at the right correct range.
Glassmaking accounts for around two thirds of feldspar used in the United States in any given year, with the majority of the balance being made up of use as fillers and in ceramics. For glassmaking purposes, feldspars are ground to 0.85 mm (20 mesh).
Fillers: Feldspars are functionally used as extenders and fillers in paints, rubbers, and plastics. It is an effective filler because of a number of factors. These factors include its stable pH, high chemical inertness, good dispersibility, impressive refractive index, resistance to frosting, high resistance to abrasion and low viscosity at high filler loading.
In paints, coatings and lacquers, ultra-finely milled feldspars are used as fillers. The non-toxic addition of feldspar is appealing as it reduces overall material cost, but does not impact on the colour density owing to its relatively low refractive indices in the region of 1.0 to 1.5.
Ceramics: Putting things in perspective, feldspar is considered the other most critical ingredient – besides clay – in the production of ceramics. It doesn’t have a
definite melting temperature, as it melts slowly throughout various temperatures. This is one of its advantages as it accelerates the melting of clays and quartz, while simultaneously allowing modulation of this crucial stage in the production process. They are generally used as fluxing catalysts to produce a glassy coating at low temperatures. They are also used as a source of alumina and alkalis in glazes.
Most often than not, feldspars improve the toughness, durability, and strength of the ceramic body. Also, they melt, soften and wet other components of the batch mix. Ceramic grade feldspars are typically ground to no more than 75 μm (200 mesh).
Porcelain: Feldspar, along with kaolin and quartz (as a form of silica) are the primary components in modern porcelain ceramics. These are ‘hard paste porcelain’ types, which compared to ‘soft paste’ are fired at temperatures around 1,400 °C, whereas ‘soft’ types are fired only at 1,200 °C. These types of porcelain
are regarded as stronger and much less likely to crack than ‘soft paste’ variants. Depending on firing type, it can resemble conventional stoneware or earthenware. As with all ceramics, it is now understood that one of the major reasons for feldspar’s inclusion is for its superior fluxing capabilities.
Enamel glazes: In enamel glazes, feldspar helps to enhance the aesthetics of the final product by ensuring that there are no errors in the final product. It is useful in the manufacturing of sanitary ware, ceramic tile glazes, tableware, giftware, electrical, and enamel frits. In sanitary wares, feldspars are used to
facilitate the optimization process.
Feldspar also has a host of other end-uses which include urethane, mild abrasives, paints, welding of red coating, production of steel and latex foam.
Welding: Potassium feldspars are very useful in the coating of welding electrodes due to their excellent fluxing properties. They are particularly used in the coating of electrodes used in the manual arc process, a process used for the welding ferrous alloys in general fabrication industries, shipbuilding, hard-facing and structural steelwork.
Abrasives: Along with magnesium oxide, magnesium chloride and other synthetic glue, feldspars are used as a bonding agent in the manufacture of wheels,
abrasives, disc and various other shapes.
Feldspar Processed Material:
- Feldspar Grits (Coarser Form)
- Feldspar Powder (100 Mesh, 200Mesh, 300Mesh, 400Mesh).
- Feldspar Lumps.
