Case Studies

Application of new intelligent coarse coal slime separator in coal preparation plant

1. Working principle of TBS separator

TBS(Teeter bed separator), is mainly used for the separation of coarse coal slime. The feeding range is 0.15-3mm, separation density is less than 1.5g /cm3, and the content of the ash product can reach less than 10%. The main components include feeding well, tank, actuator, sensor, tapered valve assembly, water distribution board and control system. The main function of the feeding well is to make the feeding evenly distributed in the middle of the TBS tank, and the aluminum oxide ceramic channel is usually used as the lining to prevent wear the actuator with linear motion spring return is the electro-hydraulic actuator, which receives the current signal from the controller or control system, and the electric hydraulic draw stem drives the discharge valve to open and close. Sensors are used to detect bed density, tapered valve assembly - discharge valve and seat.

Located in the seat at the bottom of the TBS slot, when the density exceeds the set value, the actuator pushes the push rod of the discharge valve down to discharge the heavy materials. The purpose of the water distribution plate is to evenly distribute the ascending water flow at the bottom of the whole tank, and distribute holes with an aperture of 5 mm on the upper surface. Each hole is equipped with a replaceable anti-wear plug.

Main separation principle of TBS: main water according to certain pressure and flow rate accesses the separator at the bottom of the pressure chamber, through turbulent flow board evenly distributed in the bottom of the separator and forming a rising current. Slurry is fed to the feed separator by the intermediate feed well on the side of the separator. The falling material and the rising water flow meet to disturb the bed. The difference of interference settling velocity provides conditions for separation In the dynamic stable state, particles with a density lower than the average density of the interfering bed in the feed will move with the upwelling and discharge the equipment through the overflow.particles with a density greater than that of the interfering bed will overcome the effect of upwelling and move down through the bed to become sediments, which will eventually be discharged through the discharge port at the bottom. The discharge system is controlled according to the signal sent by the density sensor in the bed that plays the role of separation, mainly by controlling the opening degree of the shuttle valve to control the sediment discharge, so as to achieve the purpose of controlling the density of the separation bed.

TBS separator applied to low density separation process achieves good efficiency, but tailing ash is low (tailings ash content 30% - 50%), and it often appears such problems like quick wear of tailings discharge outlet, outfalls easy to jam, the separation density fluctuates greatly during tailings discharge. The main reason is that the shuttle valve in the discharge mechanism discontinuous discharge process, high density line of research cases shuttle valve opening is small, in the final analysis is determined discharging structure features.

H-TBS by HOT Mining Tech applicated in a coal washing plant in Mongolia

2. Working principle of TCS separator

New intelligent TCS is a new type of intelligent coarse coal slime separation equipment based on TBS, mainly composed of the drive device, smart jamming device, platform, separation cylinder, walking into the VAT, densimeter, top water nozzle and bottom flow box and so on (main structure as shown bellow)

This separator can achieve efficient separation of 3-0.3mm slime, which overcomes the disadvantage of traditional TBS separator not suitable for high-density gangue drainage, and is suitable for the preparation of wide-grade coarse coal slime separation equipment required by the existing coal preparation process.

TCS depends on the rising water flow and the intelligent scrambler, and divides the material into two parts. according to the different particle size or density of the material. Like TBS, it produces a stable "interference bed" inside the tank by interfering with the upwelling and material flow. When the feeding particles settle at a certain speed, the water flow through the tank will rise at a certain speed. The particles with the same settling speed as the rising water flow will be suspended in the tank, forming an interference bed and generating the self-generating medium in the interference bed, thus resulting in "interference settlement".Like TBS, particles with a density greater than the interfering bed density in the feed will overcome the effect of upwelling and move down through the bed to become sediments, but in the discharge process, they will eventually be discharged through the bottom discharge port under the action of the tailings pump. The discharge system is controlled by the signal sent by the density sensor in the bed which plays the role of separation, mainly by controlling the frequency of the tailings pump and the opening of the door between the constant pressure water refill to control the sediment discharge, so as to control the density of the separation bed.

3.  Difference between TCS separator and TBS separator

The difference between TCS separator and TBS separator is that TCS separator has a unique tailings discharge mechanism and smart jammer. The TCS tailings discharging mechanism is connected with one end of the bottom flow box of the coarse coal slime separator through the replenishment pipe of the constant pressure water tank, and the other end is connected with the discharge pump inlet. The overflow tube The tailings are discharged through the outlet of the discharge pump. The constant pressure water tank of the tailings discharge mechanism ensures the stable pressure of the water tank through the discharge pipe of the overflow pipe. The bottom flow box adjusts the distance between the bottom flow and the inlet pipe of the box body by adjusting the handwheel and quick adjustment of flow and head by discharge pump set inverter. By means of pump, the uniform and stable discharge of tailings is realized, which avoids the disadvantages of unstable density of separation bed caused by intermittent discharge and easy blockage of tailings discharge outlet during discharge of shuttle valve, thus realizing the functions of low-density separation and high-density separation of gangue. But in the process of low speed operation, the intelligent jammer can not only assist the sediment to move to the discharge port, but also produce auxiliary interference, which can enhance the separation effect of the disturbed bed, so as to improve the efficiency through a structure like a harrow rack.

4. Project cases

For the first time, the TCS separator was applied to transform the slime water treatment system in Xiegou coal mine preparation plant. For 1.5 -0.2mm coarse coal slime (the bottom flow of the classifier), it enters the TCS separator for separation. The TCS cleaned coal adopts the concentrator cyclone + arc screen + the slime centrifuge to dehydrate and recover, and then blended in the washing and blending coal.

TCS tailings are dehydrated by arc screen + high frequency screen and then discharged into gangue belt. The system runs smoothly, the separation accuracy is high, and the average ash content of the tailings is more than 63% after the transformation of the TCS separation system is completed. After all 1.5-0.2mm coarse coal slime enters the TCS system for separation, the amount of discharged gangue accounts for about 30% of the feed, so that washing and mixing coal products are positioned from 20.9MJ/kg to 22.1MJ/kg, further expanding the market of high-quality thermal coal. At the same time, the system is capable of producing 20.9MJ/kg and 22.9MJ/kg washing and mixing coal products according to the market situation. After the completion of the transformation, through the field production verification, this type of TCS intelligent coarse coal slime separator has excellent performance like bottom flow discharge stable adjustable, the separation density stable, the separation accuracy high, the tailings ash content can be guaranteed to be more than 65%, the high degree of automation .

The ash content of the separation machine is 30%-33%, the concentrate ash content is 18% to 20%, and the tailings ash content is more than 65%. The test results of TCS concentrate tailings products are shown in Table 1. SO it achieve the purpose of tailings are discharged to the gangue and adding coal-washing coal to increase the heat generation of coal-washing coal. After the transformation, the calorific value of washing and mixing coal products increased from 20.9MJ/kg to 22.1MJ/kg, and the annual profit increased by more than 70 million yuan (the profit fluctuated due to the market factors of coal products).In the process system of Xiagou coal preparation plant, the application of TCS separator not only makes up for the defects of the original coal preparation process, improves the economic benefit of the enterprise, but also promotes the development of domestic interference bed separator, which is a breakthrough in the development history of interference bed separator.

5. Conclusion

TCS separator and TBS separator, RC separator has the same separation principle and the structure of the similar, but the TCS separator overcome the TBS and RC separator's technical problems like shuttle valve plug, tailings discharge discontinuity when tailings discharge is low with its unique discharge device and interference device. It improves the reliability and separation stability of the equipment and has the value of promotion.