In the early stage, most of the concentrators adopted the extensive mining and beneficiation mode due to the backward level of economic development and beneficiation technology, which led that some useful minerals still existed in the tailings.
At present, the common tailings reprocessing technologies mainly include flotation method, gravity separation method and magnetic separation method. Different tailings reprocessing technologies means different tailings reprocessing equipment. Next, we will explain to you the tailings reprocessing equipment commonly used in the above three tailings reprocessing technologies.
Use the table of contents below to navigate through the guide:
Flotation method has a wide application range and is mostly used to deal with refractory tailings in the tailings reprocessing. The common flotation equipment mainly includes mechanical stirring flotation machine and pneumatic stirring flotation machine.
The mechanical stirring flotation machine uses the mechanical agitator to achieve the pulp inflation and stirring, which belongs to the air self-suction flotation machine. In addition, it can achieve the self-suction pulp without the need of external special fan for pulp inflation.
In the tailings reprocessing, the return of its intermediate products generally doesn’t need the sand pump, so this kind of flotation cell has the obvious advantages and flexibility in the flow configuration.
Generally, the mechanical stirring flotation machine mainly includes SF flotation machine, JJF flotation machine and BF flotation machine. Among them, SF flotation machine and JJF flotation machine are more suitable for roughing and scavenging of small and medium-sized tailings reprocessing concentrator; BF flotation machine is mostly suitable for roughing and cleaning of small and medium-sized tailings reprocessing concentrator.
Compared with the mechanical stirring flotation machine, the pneumatic stirring flotation machine belongs to the external air-supply flotation machine, its agitator only plays the role of mixing, the air is forced to supply by the external special fan, and the intermediate products need to be pumped up. But the inflating volume of this kind of flotation machine can be adjusted according to the needs of flotation, and it is not easy to produce the slime phenomenon when dealing with the brittle tailings, and has low power consumption, long service cycle.
The pneumatic stirring flotation machine mainly has KYF flotation machine and XCF flotation machine, both are suitable for the various metal and non-metal tailings reprocessing. Among them, KYF flotation machine is more suitable for the roughing and concentration of large and medium-sized tailings reprocessing concentration; XCF flotation machine is suitable for roughing and scavenging of large and medium-sized tailings reprocessing concentration.
Gravity separation method is mostly used for the rare metals-containing sand tailings reprocessing. At present, the common gravity separation equipment includes shaking table, jig and spiral chute.
Shaking table mainly uses the combined action of asymmetric reciprocating movement and thin layer inclined water flow to force the material separated according to the particle size.
In the tailings reprocessing, the shaking table is mostly used to treat 2-0.02mm of tungsten, tin, tantalum, niobium tailings and other rare metals, precious metals tailings.
The jig is to stratify the materials according to the specific gravity in the vertical moving variable speed medium flow. Those minerals with small specific gravity are located in the upper layer, and those minerals with high specific gravity are located in the lower layer. Then, the well-stratified materials are discharged separately by the action of machinery and water flow.
In the tailings reprocessing, the jig is mostly suitable for treating coarse grain dissembed tailings above 3mm.
Under the action of swirling gravity and centrifugal force, the spiral chute uses the water flow speed in the chute to separate according to the specific gravity, particle size and shape difference of material.
In the tailings reprocessing, the spiral chute is often used to deal with medium and fine grain size (about -4mm) of gold, platinum, tin, tungsten, tin and other rare metal sand tailings.
In the tailings reprocessing, the magnetic separation method can be used in the tailings reconcentration and impurity removal of ferrous metals, non-ferrous and rare metals and non-metals. At present, the common magnetic separation equipment used in the tailings reprocessing mainly includes permanent magnetic drum separator, dry magnetic separator, high gradient magnetic separator.
The large angle magnetic system of permanent magnetic drum separator can increase the length of the separation zone and the number of magnetic flipping, realize the separation between magnetic minerals and non-magnetic minerals in the tailings. According to the structure of the tank, it can be divided into cocurrent type, countercurrent type and semi-countercurrent type permanent magnetic drum separator.
■Cocurrent type permanent magnetic drum separator is suitable for roughing and concentration of 6-0mm strong magnetic tailings.
■Countercurrent type permanent magnetic drum separator is suitable for roughing and scavenging of 0.6-0mm strong magnetic tailings.
■Semi-countercurrent type permanent magnetic drum separator is suitable for roughing, concentration and scavenging of 0.5-0mm strong magnetic tailings.
According to the different magnetic induction intensity, the dry magnetic separator can be divided into dry weak magnetic field separator, dry medium magnetic field separator and dry high magnetic field separator, which are more suitable for tailings reprocessing concentration in the serious water-deficient area and cold area.
■Dry weak magnetic field separator is used in the tailings pre-tailings discharging, and the limit of particle size is above 350mm.
■Dry medium magnetic field separator is used for the tailings recycling of the magnetic separation plants, purification of non-metallic mineral processing plant or the removal of highly magnetic minerals and iron impurities in advance before the high intensity magnetic separation.
■Dry high magnetic field separator is used for coarse tailings separation, iron removal of fine nonferrous metal mineral and purification of non-metallic ores.
High gradient magnetic separator uses the magnetic force, pulsating fluid force, gravity and other force fields to achieve the magnetic separation. During the magnetic separation operation, the strong background magnetic field produced by the effective electromagnet and the collecting surface that can produce a high magnetic field gradient increase the magnetic force, thus realizing the separation of weak magnetic minerals.
In the practice, the high gradient magnetic separator can be used in the tailings reprocessing of iron oxide, manganese ore, ilmenite and other weak magnetic mineral, the iron removal of quartz, kaolin and other non-metallic mineral tailings.
In the actual tailings reprocessing, the specific selection of mineral processing equipment needs to be decided according to the tailings reprocessing technology flow. It is suggested to customize the tailings reprocessing technology and equipment through the mineral processing test report, thus obtaining the ideal economic benefits.