Feldspar is an aluminosilicate mineral of alkali metals or alkaline earth metals such as potassium, sodium, calcium, and barium, and is one of the important rock-forming minerals. Pure feldspar is rarely found in nature, even in the mineral known as "potassium feldspar", there may be a symbiosis or some albite mixed in. According to the type of deposit, feldspar can be divided into pegmatite-type feldspar, white granite-type feldspar, granite-type feldspar, and feldspar-type placer.


Due to the different types of deposits and ore properties, the beneficiation process of each feldspar is also different. Common feldspar beneficiation processes mainly include hand selection, desliming, magnetic separation, gravity separation, flotation and a combination of various beneficiation methods to remove associated minerals such as quartz, iron, and mica.

Pegmatite-type feldspar beneficiation process

Generally, the feldspar quality of pegmatite-type feldspar deposits is good and the mineral composition is relatively simple, so the beneficiation process is relatively simple. The principle process of beneficiation includes sorting, crushing, grinding, and strong magnetic separation.

Sorting operation: Hand selection or color sorting to separate out large chunks of gangue minerals;

Crushing operation: Coarse crushing and crushing;

Grinding operation: Use a gravel mill or rod mill lined with ceramic lining plates and quartzite for continuous crushing operation;

Strong magnetic separation operation: Use strong magnetic separation to remove iron and other magnetic minerals, and the magnetic field strength is generally above 1200kA/m.

feldspar beneficiation process

Process flow of beneficiation of white granite-type feldspar

White granite-type feldspar minerals are uniform in mineralization and stable in quality, of which potassium feldspar and albite account for about 50-60%, and gangue minerals mainly include quartz, mica and iron-bearing minerals. Usually, this kind of deposit needs to be processed by flotation method to obtain feldspar concentrate. The main process of beneficiation is as follows:

1. Crushing operation: The raw ore is crushed to about 20mm by primary crushing (jaw crusher) and medium crushing (cone crusher);

2. Grinding and grading operation: After mixing, the crushed products are wet-ground to -20 mesh in a closed circuit operation composed of a rod mill and a trommel screen, and then use a cyclone and a spiral classifier to remove the -200 mesh level of fine particles. Granular clay impurities, -20 mesh-+200 mesh grade materials are sent to the flotation operation.

cone crusher

3. Flotation operation: Remove impurities such as mica, iron minerals and quartz. In the first stage, mica is obtained by flotation with cationic collectors (mainly amine collectors) in a weakly acidic medium. The mica is purified by flotation and wet-screened with an 80-mesh vibrating screen, and the wet mica larger than 80-mesh is sold to the mica processing plant; in the second stage, an anionic collector (mainly sulfonated oil) is used to remove iron in a weakly acidic medium. Minerals; third stage, separation of feldspar and quartz with combined collectors in mildly acidic media.

Of course, the flotation operation is appropriately adjusted according to the mineral composition. If the content of mica in the grinding product is very small, it can skip the first stage of flotation and directly enter the second stage of iron removal flotation. To meet the requirements of some glass factories, the flotation separation of feldspar and quartz in the third stage can be omitted, and the product can be directly used as a glass ingredient in the form of feldspar silica sand mixture.

flotation operation

Granite-type feldspar beneficiation process

Granite-type feldspar is a coarse-grained acidic plutonic igneous rock with finer embedded grain size than pegmatite, with quartz content of about 25-30%, and mica and iron-bearing minerals about 10%. Feldspar is its main component (alkaline), a crystalline feldspar in which potassium feldspar and albite are combined in some proportion.

Granite is embedded with fine particle size, so the cost of grinding and beneficiation is high. The beneficiation process of granite-type feldspar is roughly the same as that of white granite. The principle process of beneficiation includes crushing, grinding, classification, flotation (removal of iron, mica), and flotation (quartz, feldspar separation).

Granite-type feldspar

The flotation operation of the grinding products is determined according to the mineral composition. If the content of mica and iron is low, generally after grading and desliming, it directly enters the flotation separation operation of quartz and feldspar. If the content of impurities such as mica and iron is high, it is necessary to first remove impurities such as iron and mica by flotation, and then carry out the separation and flotation of feldspar and quartz.

Process flow of feldspar sand ore beneficiation

The main components of feldspar placer are quartz and feldspar, which are mainly formed by the accumulation of some granite and feldspar-bearing metamorphic rocks during long-term weathering. The quality of feldspar placer is not as good as that of pegmatite feldspar deposits, but because crushing and grinding operations are omitted in the mining and beneficiation process, the beneficiation cost is relatively low, and it is also one of the important sources of feldspar concentrates.

crushing and grinding operations

The beneficiation process of feldspar placer is relatively simple. The principle process of beneficiation mainly includes washing, scrubbing, classification, magnetic separation, flotation, etc.;

The above are the common four types of feldspar beneficiation process. Before feldspar beneficiation, each mine owner must measure the chemical composition, mineral composition, ore structure, particle size composition, raw ore density, relative grindability of raw ore and other properties, and scientifically select the single or combined recommended in the beneficiation test report. Process flow to remove associated minerals such as quartz, iron, mica, etc., and effectively recover feldspar concentrate rich in potassium and sodium.

Related Articles

Submit Your Requirement Below For Mineral Processing Proposal!

Please contact whatsapp number via +86 13918045927 for detailed information!