Feldspar is a group of minerals composed of aluminosilicates of potassium, sodium, calcium and barium. The main chemical components are SiO2, Al2O3, CaO, K2O, Na2O.
Potassium-sodium feldspar beneficiation process
In recent years, with the decrease of feldspar mine and the decline of quality, the quality requirements of products continuously improve. The comprehensive recovery of mines is developing, more complicated sorting operations such as gravity selection, flotation, high-gradient magnetic separation have been introduced. It is possible to remove associated minerals such as quartz, mica and iron-containing titanium.
Potassium-sodium feldspar ore dressing equipment mainly includes jaw crusher, ball mill, mud removal bucket, cyclone, strong and weak magnetic separator, flotation machine and so on.
1. Crushing: The massive ore is crushed by a jaw crusher.
2. Ball milling: The crushed ore is ground by a ball mill.
3. Desliming: The finely ground material is sent to a desliming bucket or a cyclone for de-sludge.
The mud in feldspar includes the original argillaceous minerals and the secondary mud after grinding. The iron content in the argillaceous minerals is usually high. For this reason, the de-sludge can remove a large amount of iron minerals early, and can also reduce the operation of magnetic separation, and after entering the flotation section, the consumption of the medicament could be effectively reduced. The content of secondary mud is closely related to the fineness of grinding. The finer the fineness of grinding, the more secondary mud, and finally the lower the yield of potassium albite feldspar concentrate. The thick fineness of grinding could lead to partial iron minerals cannot be dissociated, and then cannot be effectively removed, which could have a great impact on the power consumption and wear of subsequent equipment. Therefore, proper grinding fineness is crucial, but different potash feldspar and albite minerals have different grinding fineness.
4. Magnetic separation: magnetically remove the magnetite and other weak magnetic minerals through the strong magnetic separator after sorting and removing the slime.
Magnetic separation includes weak magnetic separation and strong magnetic separation. Weak magnetic separation removes ferromagnetic iron from potassium sodium feldspar and secondary iron produced during grinding. Strong magnetic separation removes weak magnetic mineral iron oxide in ore. For the concentrates of potash feldspar and albite minerals, the most important factor affecting the whiteness is the iron content, so magnetic separation is essential for feldspar and is the most efficient removal of iron minerals.
5. Flotation: Currently, applying strong and weak magnetic separators to remove iron in potassium feldspar is not suitable for all K-feldspar mines. The flotation machines could solve the problem, which has a wide application currently.
Flotation includes reverse flotation and positive flotation. Positive flotation is usually applied to minerals with lower potassium and sodium feldspar grades and higher quartz content. Positive flotation can enrich potassium and sodium feldspar and reduce silicon content. Reverse flotation is usually to remove impurities, reduce the content of argillaceous minerals, iron minerals, calcium and magnesium carbonate minerals, rutile and mica in feldspar minerals. As can be seen above, reverse flotation needs to target the impurity minerals contained in the ore and achieve targeted removal. For this purpose, different collectors need to be used for capturing. For the same impurity minerals in different ore properties of potassium albite feldspar mine, the collector used is different. We need to choose collectors with high impurity removal rates and low potassium-sodium feldspar loss rates for impurity minerals. Experimental studies could be effectively applied to configure different flotation reagents for such many different factors.
6. Pickling powder: using sulfuric acid as the pickling agent, adjusting according to the iron content of the potassium feldspar fine powder and the acid concentration. With the certain sulfuric acid concentration, the weight of sulfuric acid added is proportional to the iron content of the potassium feldspar. The ferric oxide and triiron tetroxide could be completely removed by pickling, and the ferrous sulfate solution is separated to obtain potassium feldspar fine powder.