What are the Feldspar Mining Processes?

According to the type of deposit, feldspar can be divided into pegmatite feldspar, white granite feldspar, granite feldspar and feldspar placer. Because of the different deposits and ore characteristics, the feldspar mining process is quite different with each other. The common feldspar mining processes include hand sorting, desliming, magnetic separation, gravity separation, flotation and combined process, which can separate quartz, iron, mica and other minerals.

1. Pegmatite feldspar mining process

Commonly, the pegmatite feldspar has good quality feldspar ores, which has simple mineral constitute. So, the pegmatite feldspar mining process is rather simple than other minerals, including selecting, crushing, grinding, and strong magnetic separation.

• Selecting: hand sorting or color sorting, which can separate big chucks.

• Crushing: rough crushing and fine crushing.

• Grinding: continuous grinding operation is carried out by using the gravel mill or rod mill lined with ceramic liner plate and quartzite.

• Strong magnetic separation: Strong magnetic separation is carried out for separating iron and other magnetic minerals. The magnetic strength is over 1200kA/m.

2. Albite feldspar mining process

Albite feldspar has well-proportioned mineral constitute and stable quality. The potash feldspar and soda feldspar are about 50~60%. The gangue minerals include quartz, mica, and iron minerals. This kind of feldspar usually transfer into feldspar concentrates through flotation process. The albite feldspar mining process is mainly:

• Crushing: The raw ores are crushed roughly (in jaw crusher) and middling (in cone crusher) into 20mm.

• Grinding and classification: Crushing product is mixed and fed into the close recycle of rod mill and roller screen into under 20 mesh. Then the fine clay impurities under 200 mesh are removed through hydrocyclone and spiral classifier. The minerals between -20 mesh and -200 mesh are sent to flotation workshop.

• Feldspar flotation: Remove impurities such as mica, iron ore and quartz. In the first stage, mica was obtained by flotation in a weakly acidic medium with cationic collectors (mainly amine collectors). Mica is purified by flotation and wet-screened with 80 mesh screen, and sold to the mica processing plant for more than 80 meshes. In the second stage, anion collector (mainly sulfonated oil) was used to remove iron ore in weakly acidic medium. In the third stage, feldspar and quartz were separated with a combination collector in a weakly acidic medium.

Of course, the feldspar flotation operation is adjusted according to the mineral composition. If the content of mica in the grinding products is very small, can pass the first stage flotation, directly into the second stage iron removal flotation; If the content of iron and quartz can meet the requirements of some glass factories after the first and second stage flotation of the grinding products, the flotation separation of feldspar and quartz in the third stage can be eliminated and the products can be directly used as glass batting in the form of feldspar silica sand mixture.

3. Granite feldspar mining process

Granite feldspar is a coarse-grained acid plutonic igneous rock. Its Mosaic grain size is smaller than pegmatite, quartz content accounts for about 25-30%, mica and iron content accounts for about 10%. Feldspar is its main constituent (alkaline), that is, a kind of potassium feldspar and sodium feldspar in a certain proportion of the combination of crystalline feldspar.

Granites have fine grain size, so the cost of grinding and dressing is higher. Granite-type feldspar mining process flow is roughly the same as that of white granite feldspar mining process. The process principle of granite feldspar mining process includes crushing, grinding, grading, feldspar flotation (except iron and mica), feldspar flotation (quartz and feldspar separation).

The feldspar flotation operation of grinding products shall be determined according to the mineral composition. If the content of mica and iron is low, it will enter the flotation separation of quartz and feldspar directly after graded desilting. If the content of impurities such as mica and iron is high, it is necessary to remove the impurities such as iron and mica by flotation first, and then carry out the separation and flotation of feldspar and quartz.

4. Feldspar placer mining process

Feldspar placer is mainly composited with quartz and feldspar. It is mainly formed by the accumulation of some granite and feldspathic metamorphic rocks during long-term weathering. Feldspar placer is inferior to pegmatite feldspar deposit in quality, but because the crushing and grinding operations are neglected in the mining and processing process, the cost of feldspar placer mining process is relatively low, and it is also one of the important sources of feldspar concentrate at present.

The principle of feldspar placer mining process is rather simple. It mainly includes: washing, scrubbing, classifying, magnetic separation, feldspar flotation and so on. The subsequent separation operation shall be determined through the composite of classifying products.

The above is the common four types of feldspar mining process. Before the feldspar flotation, the owner must be undressed ore chemical composition, mineral composition, ore structure, composition, density of run of mine ore, ore grade is relatively grinding degree properties are measured, such as scientific selection of experiment report recommended by single or combined feldspar mining process, to remove the quartz, iron, mica and other associated minerals, effective recycling is rich in potassium, sodium feldspar concentrates.