New technology and technology for jigging beneficiation (2)
(2) Periodic curve with stationary period The periodic curve with stationary period is shown in Fig. 2, also known as Meyer curve. The entire bed can be lifted in a rapid increase in flow, then the flow is stationary relative to the water velocity decreases, loose long period, large amount of processing equipment, is selected from coal-free piston jig similar such period.
(III) Cycle curve of rapid rise The cycle curve of fast rise is shown in Figure 2. It was evolved from the cycle of BM Bird (Bird1947). A rapid rise in water flow raises the bed as a whole and then the water flow slowly drops, reducing the relative velocity of the bed. It is beneficial to the differential layer of mineral density. In recent years, hydraulic drive jigs and cam drive jigs have been widely used.
(4) Slow rising cycle curve The periodic curve of slow rising is shown in Figure 2. Also known as the B. Thomas (ToMas) curve, the water flow looses the bed in a continuous low-speed rise, and the action time is long, which helps to improve the processing capacity of the equipment. However, because the bed is under hydrodynamic action for a long time, it is suitable for sorting narrow-grain grade ore.
4. The light products of the jig discharge mechanism of the jig are generally discharged from the end raft with the water flow, and there are basically two methods for discharging the heavy products, namely, the sieve discharge and the sieve discharge, and sometimes The two are combined.
(1) Through the sieve discharge The heavy product is discharged into the bottom box through the sieve hole, and then taken out in an appropriate manner. The discharge process is shown in Fig. 3. In order to control the discharge speed without leaking light minerals, a layer of artificial bed is often placed on the screen surface. It is close to or slightly less than a density heavy mineral ore or metal blocks constituting the ball. The particle size is 1.5 to 2 times the size of the mesh. The bed also undulates with the rise and fall of the water flow, and acts as a gate for heavy minerals moving downward through the bed gap. The amount and quality of the heavy products under the screen can be adjusted by changing the thickness of the artificial bed or the particle size of the bed.
(2) Drainage on the sieve The discharge on the sieve is divided into two methods: central pipe discharge and one end discharge.
(1) The central pipe discharge method is used when the small mining diaphragm jig discharges the coarse concentrate. As shown in Fig. 4, the discharge pipe is arranged at the center line of the jigging chamber near the tailing end. The upper end of the material pipe is higher than the screen surface by a certain distance, and the outer casing is provided with a casing. The bottom edge of the casing has a certain height from the screen surface and can be adjusted. The heavy mineral accumulated outside the pipe enters the casing through the bed pressure, and then the central pipe Discharge to the outside of the machine. Adjust the distance between the lower edge of the casing and the screen surface to change the amount and quality of heavy product discharge. This discharge method is suitable for use in concentrate production. [next]
(2) One-end discharge method "This refers to the discharge of heavy products in the lateral opening above the sieve surface at one end of the jig chamber. In order to control the discharge speed, various discharge devices are often arranged at the discharge opening. The jig for mineral processing Generally, a simple vertical gate is provided, as shown in Figure 5. Two gates are installed inside and outside the discharge channel. The function of the outer gate is to prevent light minerals from entering the heavy product, and the inner gate is to control the discharge speed. It can be adjusted. The cover above the gate should be opened to allow the internal pressure to communicate with the atmosphere.
5. There are many types of jig jigs. According to the way of promoting water movement, they can be divided into:
(1) Piston jig;
(2) diaphragm jig;
(3) Hydraulic agitating jig;
(4) moving sieve jig;
(5) No piston jig.
The piston jig was the earliest, but due to the leakage of the piston, the transmission efficiency is low and it is rarely used. At present, the separation of metal ore mainly uses a diaphragm jig, which seals the water with a rubber diaphragm, which helps to improve the transmission efficiency of the water flow, but the equipment is not suitable for large-scale. The large jig for coal preparation mainly uses a wind-driven, pistonless jig. The hydraulic agitated jig only intermittently rises the water flow, and the equipment is compact, and is installed in closed-circuit grinding to capture large heavy minerals. The moving sieve jig appeared earlier, but the mechanical transmission part of the park was more complicated, and it was rarely used. In recent years, hydraulic drive was used to make a moving sieve jig for processing large ore and coal for raw materials. Pre-selection, there is a trend of re-development.
(1) Diaphragm Jig According to the installation position of the diaphragm, the diaphragm jig can be further divided into:
(1) a side-by-side diaphragm jig;
(2) lower diaphragm jawper;
(3) Side-moving diaphragm jig.
In the shape of the jigging room, the diaphragm jig can also be divided into rectangular, trapezoidal, and round jigs. According to the number of series of jigging chambers, it can be divided into single room, double room, three room, etc.; according to the number of juxtaposition chambers, it is divided into single row and double row jig. The area of ​​the diaphragm is generally smaller than the area of ​​the screen, the ratio of which is called the stroke factor. Written as β, the value of which is mostly less than 1.
A side-by-side diaphragm jig This model has only one type of screen width × length = 300 × 450 mm side-moving double-chamber jig, commonly known as Dianval or Denver type, the structure of the device is shown in Figure 6. The two jips are connected in series with a 50 mm drop in the middle. The eccentric link mechanism is used to drive the two diaphragms up and down alternately by the lever. From the feeding end, the left side of the jib room is the left type jig, and the right side is the right type jig. The eccentric handle is a double eccentric structure, and the inner eccentric shaft and the outer eccentric sleeve each have an eccentricity of 9 mm, so the range can be adjusted from 0 to 36 mm, and the mechanical stroke of the device is 0 to 25 mm after the lever arm is converted. The punching was adjusted by changing the pulley. The design stroke was 322 times/min and 420 times/min. The actual application showed that the punch was larger.
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