Phosphate rock is mostly produced in sedimentary rocks, but also in metamorphic rocks and igneous rocks. Except for some cases, phosphorus in minerals always exists in the form of orthophosphate, and the main mineral of phosphorus is apatite.
Phosphorus is an important chemical raw material and an essential element for the growth of crops. Phosphorus for industrial use needs to be extracted from phosphate rock for the manufacture of yellow phosphorus, red phosphorus, phosphoric acid, phosphate fertilizer and phosphate.
Phosphate ore processing and production process
The processing and production process of phosphate rock mainly includes three processes: crushing, grinding and beneficiation.
In the crushing process, the three-stage closed-circuit crushing is a more modern method suitable for the crushing of high-hardness phosphate ore, which can complete the work of ore crushing and partial dissociation, thereby improving the subsequent grinding efficiency.
In the grinding process, the two-stage one-closed grinding is an efficient grinding process, which can make the phosphate rock more fully ground.
In the beneficiation process, following the direct flotation process, my country has successively developed ore beneficiation and enrichment processes such as roasting and digestion of sedimentary phosphorite, scrubbing and desilting, reverse-positive (forward-reverse) flotation, and heavy media. Among these techniques, direct flotation, reverse flotation, scrubbing de-sludge, and dense medium sorting have been successfully applied.
The first stage: crushing and screening
The large pieces of phosphate rock are evenly sent to the jaw crusher or mobile jaw crushing station (primary crushing) by the vibrating feeder through the silo for coarse crushing.
After the coarsely crushed phosphate rock is screened by the vibrating screen, it is sent to the single-cylinder hydraulic cone crusher (middle crushing) by the belt conveyor for secondary crushing.
The medium crushed phosphate rock material is sent to the multi-cylinder hydraulic cone crusher for fine crushing.
Jaw crusher (referred to as jaw crusher) is mainly used for medium-sized crushing of ore and bulk materials. It can crush materials with a compressive strength of up to 320Mpa. Shanghai Shibang has PE and PEW series jaw crushers, the product specifications are complete, the feeding particle size is 125mm ~ 1020mm, the ideal single machine output is up to 800t/h, it is the ideal equipment for primary crushing.
Sturdy structure and stable performance:
Adopt the world's advanced technology, Baosteel high-quality steel, American Timken bearings, heavy-duty eccentric shaft, and finite element analysis technology to make it strong in structure, stable in performance, and long-term operation.Large crushing ratio, high output:
heavy-duty sheave and flywheel, optimized jaw plate, make the crushing force larger. "V" design makes the feeding port consistent with the actual, the crushing cavity is deep and has no dead zone, and the output is higher.Easy operation and energy saving:
hydraulic lubrication and wedge adjustment make the operation more convenient and flexible, the lubrication is more convenient, the energy saving of a single machine is 15% to 30%, and the energy saving of the system is more than doubled.
Solid structure and stable performance:
It adopts integrated frame castings, heavy-duty central shaft, and both ends of the main shaft are supported, with strong bearing capacity and large crushing force. Using advanced technology, Timken bearings imported from the United States, stable operation and long service life.Automatic control, easy operation:
PCL touch screen operation and hydraulic adjustment of the discharge method are adopted, the discharge port is easy to adjust, and the maintenance is convenient.Integration of thin oil lubrication:
The integrated system of thin oil lubrication is adopted, which makes lubrication more efficient and saves lubricating oil. The use of air cooling system to cool thin oil overcomes environmental limitations and makes the overall process more stable and efficient.
The second stage: Grinding
The 0-12mm phosphorus powder sieved by the vibrating screen is evenly sent to the ball mill for grinding, and sieved by the spiral classifier, and those that do not meet the requirements are sent to the ball mill to continue grinding.
HGM Ultrafine Mill
The ultra-fine non-metallic ore pulverizer can grind stones with a Mohs hardness of less than 7. The fineness can be freely adjusted between 150-3000 mesh. The equipment occupies a small area, runs stably, is simple to operate and easy to maintain.
CLUM Vertical Mill
The output of CLUM vertical mill is larger than that of ultra-fine mill, which is suitable for large-scale milling production lines. The mill produced by this equipment is of better quality, higher purity and more subdivision content. 2um content can reach 60%.
The third stage: Magnetic selection
The phosphorus powder that meets the beneficiation requirements is sent to the flotation machine for flotation to remove impurities.
Magnetic separator is a device that uses appropriate strength of magnetism to separate iron powder in powdery granules. Magnetic separator is widely used in beneficiation, suitable for wet magnetic separation of magnetite, pyrrhotite, roasted ore, ilmenite and other materials with particle size below 3mm, and also used for coal, non-metallic ores, building materials and other materials. Iron removal is one of the most widely used and highly versatile machines in the industry.
The fourth stage: Drying
Phosphorus can be obtained through subsequent processes.
Dryer is a commonly used equipment after mine beneficiation, including a rotating drum, the inner drum is driven by a belt, and there is hot air around the drum for evaporating water. The drying drum adopts the principle of forward and reverse rotation of the drum to achieve the effect of drying the items without winding, so that the moisture in the material can be removed.