The common fluorite ore dressing processes include gravity separation and flotation process. Gravity separation process can be used for coarse-grained fluorite ore. And flotation process can be used to process fluorite ore that is associated with impure minerals and the granule of value mineral is so tiny. Fluorite is often associated with quartz, barite, calcite, sulphide and other minerals. According to different ore properties, Xinhai would select different flotation processes.
Ⅰ. Crushing and Screening
Due to different properties of fluorite ore in different areas, Xinhai usually adopts three stage a closed-circuit or three opening crushing process. The crushing equipment used in fluorite ore dressing process is shown below.
|Jaw Crusher||Coarse Crushing||<1250|
|Standard Cone Crusher||Secondary Crushing||<350|
|Short-head Cone Crusher||Fine Crushing||<130|
|Auto Centering Vibrating Screen||Screening||<30|
The grinding process often uses two-stage grinding. When fluorite is closely associated with other minerals, one stage grinding usually cannot realize monomer separation between fluorite ore and associated minerals. Therefore, roughing concentrate regrinding is commonly used in refractory fluorite ore dressing process after one stage grinding, which is beneficial to the later separation and improves processing indicators. In recent years, Xinhai has successfully produced a series of energy-saving ball mills, then widely used in many upgrading mineral processing plants, and has achieved obvious energy saving effect. Energy saving ball mills are shown below.
The main fluorite ore dressing processes include gravity separation process and flotation process.
Gravity separation process
Application: High-grade fluorite deposits and 6-20mm particle ore
Features: remarkable separation efficiency, simple equipment structure, convenient operation. The main gravity separation equipment in fluorite beneficiation process is the jig, especially diaphragm jig. Xinhai successfully produced two types of diaphragm jig: left-type and right- type diaphragm jig, and the maximum size is 6-8mm. Xinhai jig is widely used in fluorite ore dressing process and other minerals beneficiation process, such as gold, tin and tungsten ore.
Application: fluorite ore that is associated with impure minerals and the granule of value mineral is so tiny
1.Separation between fluorite and sulfide ores
Most plants use xanthate as the collector to float sulfide ore firstly, then float fluorite ore. Xinhai commonly uses fatty acids collector in fluorite ore flotation process. In order to achieve better flotation effect, Xinhai would add a small amount of sulphide inhibitor to inhibit residual sulfide ore, thus to improve fluorite concentrate grade.
2.Separation between fluorite and bariteIn 2011, Xinhai undertook 400tpd fluorite ore dressing plant in Outer Mongolia. The ore type was fluorite - barite type deposit, the main mineral were fluorite and barite, and the gangue minerals were quartz, calcite. Finally, Xinhai decided to adopt a roughing, a scavenging, and three cleaning flotation processes. The chemical compositions of ore were shown below.
The study shows that the amount of oleic acid needed for fluorite flotation, barite flotation and calcite flotation is different. Fluorite flotation needs maximum oleic acid, whereas, calcite flotation needs minimum oleic acid. When the flotation pulp is neutral, the flotability of fluorite and barite is close. When PH value of pulp is above 10, only the calcite has the best flotation effect; when the pulp is acidic, fluorite has a better flotability than barite, which can realize the separation between fluorite and barite.
This fluorite ore dressing process uses oleic acid as collector, sodium silicate as inhibitor under 8.5-9 PH value pulp. Xinhai adopts sodium carbonate and sulfuric acid as PH adjusting agents. Sodium carbonate not only regulates PH value, but also disperses slime. The amount of sodium carbonate and oleic acid should be appropriate. In order to obtain high-quality fluorite concentrate, Xinhai often inhibits barite then float fluorite to get fluorite and barite concentrate.
3.Separation between fluorite and quartz
Xinhai uses fatty acid as the collector to collect fluorite ore, and sodium silicate as the inhibitor to inhibit quartz. Less amount of sodium silicate will cause worse inhibition effect, but activates fluorite in the flotation process. However, over sodium silicate will inhibit fluorite flotation. Therefore, the amount of sodium silicate should be controlled appropriately. In order to enhance the inhibitory effect on quartz, Xinhai will add some polyvalent metal ions, which can inhibit quartz and calcite.