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, and even minerals known as "potassium feldspar" may coexist or mix with some sodium feldspar. According to the type of mineral deposit, feldspar can be divided into pegmatite type feldspar, granite type feldspar, feldspathic sand ore, etc.

Feldspar Ore 

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

1、 Mineral processing technology flow of pegmatite type feldspar

Generally, the quality of feldspar in pegmatite type feldspar deposits is good and the mineral composition is relatively simple, so their beneficiation process is also relatively simple. The beneficiation principles and processes include sorting, crushing, grinding, and high-intensity magnetic separation operations.

Picking task: manually or color select to separate large vein minerals;

Crushing operation: coarse crushing and crushing;

Grinding operation: Continuous crushing operation is carried out using gravel mills or rod mills lined with ceramic liners and quartzite;

◆ High intensity magnetic separation operation: High intensity magnetic separation is used to remove magnetic minerals such as iron, and the magnetic field strength is generally above 1200kA/m.

2、 Mineral processing technology flow of Baigangyan type feldspar

The Baigangyan type feldspar minerals have uniform mineralization and stable quality, with potassium feldspar and sodium feldspar accounting for about 50-60%. The main gangue minerals are quartz, mica, and iron bearing minerals. Usually, this type of deposit requires flotation treatment to obtain feldspar concentrate, and its beneficiation principles and processes mainly include:

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

(2). Grinding and classification operation: After mixing, the crushed products are wet ground to -20 mesh in a closed-loop operation composed of a drum screen, and then fine clay impurities of -200 mesh level are removed using a cyclone and a spiral classifier. The -20 mesh -+200 mesh level materials are sent to flotation operation.

(3). Flotation operation: Remove impurities such as mica, iron minerals, and quartz. In the first stage, mica is obtained by flotation using cationic collectors (mainly amine collectors) in weakly acidic media. Mica is purified by flotation and subjected to wet sieving with 80 mesh. Wet mica with a mesh size greater than 80 mesh is sold to mica processing plants; In the second stage, use anionic collectors (mainly sulfonated oil) to remove iron containing minerals in weakly acidic media; In the third stage, a combination of collectors is used to separate feldspar and quartz in weakly acidic media.

Of course, flotation operations are adjusted appropriately based on mineral composition. If the mica content in the grinding product is extremely low, it can bypass the first stage flotation and directly enter the second stage iron removal flotation; If the iron and quartz content of the ground ore products can meet the requirements of certain glass factories after the first and second stage flotation operations, the third stage of feldspar and quartz flotation separation can be omitted, and the products can be directly used as glass ingredients in the form of a mixture of feldspar and silica sand.

3、 Mineral Processing Process of Granite type Feldspar

Granite type feldspar is a coarse-grained acidic deep-seated igneous rock, with a finer embedded grain size than pegmatite. The quartz content accounts for about 25-30%, and mica and iron containing minerals account for about 10%. Feldspar is its main component (alkaline), which is a crystalline feldspar composed of potassium feldspar and sodium feldspar in a certain ratio.

Granite is embedded with fine grain size, resulting in higher grinding and beneficiation costs. The beneficiation process of granite type feldspar is roughly the same as that of Baigangyan. The beneficiation principles include crushing, grinding, grading, flotation (excluding iron and mica), and flotation (separating quartz and feldspar) operations.

The flotation operation of grinding products needs to be determined based on the mineral composition. If the content of mica and iron is low, it usually goes through graded desliming and 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 the impurities such as iron and mica by flotation, and then carry out the separation flotation operation of feldspar and quartz.

4、 Mineral processing technology flow of feldspar sand ore

The main components of feldspar sand ore 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 sand ore is inferior to that of pegmatite feldspar ore deposits, but due to the omission of crushing and grinding operations in the mining process, the cost of beneficiation is relatively low, and it is currently one of the important sources of feldspar concentrate.

The beneficiation process of feldspar sand ore is relatively simple, and the beneficiation principles mainly include washing, scrubbing, grading, magnetic separation, flotation, etc; Graded products need to be determined based on mineral composition for subsequent selection operations.

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