Types of fluorite mines in nature

According to the different gangue minerals, fluorite ore can be divided into four types, namely quartz-type fluorite ore, carbonate-type fluorite ore, barite-type fluorite ore and sulfide-type fluorite ore.
 
1. Quartz-type fluorite ore: The main minerals are fluorite and quartz, and the content of fluorite can reach 80% to 90%.Contains a small amount of calcite, barite and sulfides.

2. Calcite-type fluorite ore: The main minerals are fluorite and calcite.The content of calcite can reach more than 30%, and there is a small amount of quartz, which sometimes forms a quartz-calcite-fluorite ore.

3. Barite-type fluorite ore: The main minerals are heavy spar and fluorite, with a barite content of 10%-40%.This type of ore is often accompanied by pyrite, galena, sphalerite and other sulfides, and sometimes the quartz content increases to form quartz-barite-fluorite ores.

4. Sulfide-type fluorite ore: Its mineral composition is basically the same as quartz-fluorite, but it contains more metal sulfides, and sometimes the content of lead and zinc can reach industrial grade.

Flotation process of different fluorite mines
 
1. Flotation separation of fluorite and quartz
 
Quartz-containing fluorite ore is also more common. Quartz-type fluorite ore is mainly composed of fluorite (content as high as about 85%) and quartz, with only a small amount of calcite, barite and sulfides.

The key to the selection is mainly the silicon reduction of the concentrate.Use fatty acids as a collector to flotation fluorite, water glass as an inhibitor of quartz, and sodium carbonate to adjust the pH value of the slurry to 8~9.The amount of water glass should be controlled well. In a small amount, it has an activation effect on fluorite, but the inhibition effect on quartz is not enough, and fluorite will be suppressed in excess.
 
In order to minimize the amount of water glass added and achieve the inhibitory strength of quartz vein stone, multivalent metal ions (such as Al3+, Fe3+) and alum, aluminum sulfate, etc. are often added at the same time as water glass.
 
In addition, the addition of Cr3+ and Zn2+ ions is also effective. These ions not only have an inhibitory effect on quartz, but also on pyrolysis.
 
2. Flotation separation of calcite-fluorite type
 
The main reason for the difficult separation of calcite-type fluorite ore is that calcite and fluorite are both calcium-containing minerals with similar surface physical and chemical properties. When they coexist in solution, they are prone to mutual transformation between minerals.
 
To achieve the separation of calcite and fluorite, the pH value of the slurry must be adjusted, and then combined with the collector to achieve a good separation effect.In the range of pH value of 8~9.5, fluorite low temperature collector ZN136 is used as the collector, and both ores can float.
 
For fluorite minerals that contain more complex calcite, limestone, dolomite, etc., tannin and lignin sulfonates have a better effect on inhibiting these gangue minerals.
 
3. Flotation separation of barite-fluorite type
 
The difficulty of mineral processing of barite-type fluorite ore is that the floatability of barite and fluorite is similar, making it difficult to separate the two.
 
For fluorite ore associated with barite and calcite, the flotation process can be selected：
 
Oleic acid is used as the collector to separate fluorite, while dextrin is used to inhibit barite and calcite, and aluminum salt is used to activate fluorite to achieve the best fluorite flotation effect.
 
For fluorite ores with more complex calcium content, such as calcite, limestone, and dolomite with higher content associated with them, it is recommended to use fluorite ores with more complex calcium content.
Stone, etc., tannin or lignin sulfonate can be used to achieve satisfactory mineral processing technical indicators.
 
4. Flotation process of sulfide fluorite ore
 
The composition of sulfide-type fluorite ore is similar to that of quartz-type fluorite mineral, but the content of metal sulfides is higher, and sometimes the content of lead and zinc can reach industrial grade.Therefore, while developing and using fluorite, the recovery of metal ores must also be considered.
 
For fluorite with sulfide ore associated with it, the sulfide ore is generally floated out with yellow medicine collectors, and then fatty acid agents are added to flotation the fluorite.
 
Sometimes in fluorite flotation operations, a small amount of sulfide inhibitors (such as cyanide) are added to suppress residual sulfides to ensure the quality of fluorite concentrate.
 
In addition, roasting, leaching and other processes can also be used to extract valuable metals and decompose fluorite. The process is relatively simple, and high-quality fluorite products can be prepared while comprehensively recycling valuable metals.

Production example

The ore of a certain fluorite mine has low grade, high degree of oxidation, fine fluorite particle size and low hardness. Xingmuang Group passed the fluorite mineral processing test and designed a flotation production process with one rough and two grinding and seven selected flotation based on the ore characteristics. The appropriate inhibitors were selected to make the concentrate grade reach 92.8% and the recovery rate reached 88.7%, which brought continuous economic benefits to the mineral processing plant.The main equipment is as follows：