Mineral powder machine maintenance paper

1.

The equipment needed for the ore powder proction line includes the main equipment, vertical mill, and the rest are auxiliary equipment: motor, st collector, finished proct bin, conveyor belt, belt conveyor, elevator, feeder, etc

working principle of main equipment:

slag enters into the mill through the screw feeder, and the material falls to the center of the grinding plate under the action of gravity. The grinding plate is connected with the recer and rotates at a constant speed. Through the rotation of the grinding plate, the material is evenly distributed on the lining plate of the grinding plate. Under the pressure of the hydraulic system, the grinding plate is connected with the recer, The grinding roller nips the slag material and grinds it

under the action of centrifugal force, the crushed slag is thrown to the edge of the grinding plate, and most of it is blown back to the grinding plate to continue grinding under the action of high-speed air in the wind ring, and part of the powdery material rises to the separator through the middle shell of the mill with the high-speed air. In this process, the material and hot gas are fully heat exchanged, and the water is evaporated rapidly, so that the remaining water is less than 1%. The materials that have not been ground to the specified requirements are selected by the separator and sent back to the grinding plate for regrinding. The materials passing through the separator enter the st collector with the air flow

process flow of slag proction line:

the stacked slag is picked up and fed by forklift and transported by belt conveyor. In the process of transportation, slag raw materials are removed and screened by iron remover and vibrating screen, and then enter the vertical mill for grinding through weighing equipment bin and hoist. With the help of the hot air provided by the hot blast stove, the ground slag is selected by the powder concentrator and dried at the same time. The slag powder meeting the fineness requirements is finally transported to the st collector for collection and storage, and then enters the finished proct warehouse for storage by air conveying chute and elevator

profile of vertical mill:

2. Which mill is better? Gypsum powder mill, then, this should be the United States is better

3. PLC control system of mine hoist (1) current situation of domestic hoist (1) AC drive mode adopts series resistance speed regulation AC drive mode, including single rope and multi rope series. Most of them adopt the speed regulation method of changing slip ratio s, which proces a lot of slip power in speed regulation and consumes a lot of electric energy on the additional resistance of rotor, The result is that the economy of speed regulation becomes worse. Few hoists adopt cascade speed regulation method, which has narrow speed regulation range and large investment 2 DC drive mode is widely used in coal mines in China, but most of them are SCR-D electric control system of mine hoist introced in 1980s and made in China before mid-1990s. The regulation, control and protection circuits of these electronic control systems are basically analog. This system has some defects e to the limitation of component design and manufacturing level 3 Research and development 1. Domestic large DC hoist and electric control system has been graally improved and promoted. 2. The efficiency of high-power variable-frequency speed control electric hoist can reach 98%. Domestic organizations have studied this system and applied it to actual proction. 2、 PLC hardware composition and principle PLC is mainly composed of power supply, CPU, communication unit, high count unit, analog I / O unit, digital I / O unit and other hardware 1 The main control PLC system consists of power supply, CPU, communication unit, high count unit, analog I / O unit, digital I / O unit and other hardware. Installed in the main control cabinet. The auxiliary control PLC system consists of power supply, CPU, communication unit, high count unit, analog I / O unit, digital I / O unit and other hardware 2 Basic characteristics of each unit: 1. Power supply unit: the input voltage of power supply is 100-240V AC, which provides bus power and basic power for PLC; 2. CPU unit: CPU unit is the core of PLC, including memory interface and programming interface, which is the carrier of program execution. A memory mole inserted on the memory mole uses a lithium battery to keep the contents of ram; PLC can be set to "stop" or "run" mode for program execution. 3、 Control principle (1) stator control loop when the wellhead or bottom of the well sends a start-up signal to the machine room, if the main power supply and control power supply are connected at this time; The oil pump motor has been running; Oil temperature and oil pressure are normal; The brake handle and control handle are in the zero position, the overwinding reset, brake adjustment change-over switch, maintenance phase change-over switch and maintenance shift change-over switch are in the normal position, the brake change-over switch is in the pedal position, and it is ready to start the hoist (winch). Under normal conditions, if the brake handle is pushed forward slowly to release the brake, when the oil pressure reaches the opening voltage, the control handle is pushed forward or backward at the same time, the main contactor is closed immediately, and the main motor stator is connected with power, then the hoist (winch) starts to rotate forward or backward, so as to lift or lower the load 2 After the stator circuit of the rotor control circuit is powered on, the control handle is still in the power supply state, the additional resistance of the rotor circuit of the main motor is added, and the output torque of the motor shaft is only 30-40% of the rated torque. This torque can eliminate the gear clearance of the transmission system and smoothly tighten the steel rope to rece the impact. It can also start the hoist (winch) with light load. At this time, the hoist (winch) runs stably on the preparatory stage. At this time, the hoist (winch) will proce a crawling speed of 0.3-0.5 M / s when it is under light load, so as to check the shaft and wire rope, and meet the requirements of the tramcar crawling on the throwing Lane in the inclined shaft lifting. Push the control handle forward or backward gear by gear, PLC will close 1jc-5jc (or 8jc) respectively according to the starting current and gear delay, and cut off the rotor resistance of the motor in sections, so as to realize the transformation from the preparatory stage to the acceleration stage, and the motor will accelerate graally. When the handle is pushed to the front end or the last end, the constant speed contactor (the last acceleration contactor) acts, all the additional resistance is cut off, and the hoist (winch) accelerates and enters the constant speed stage. The cutting off of motor rotor is based on the principle of current function and time function. The series of external resistance of motor is determined by motor power and rotor parameters. Generally, grade 5 or grade 8 starting resistance is adopted. The hoist (winch) can be adjusted from low speed to high speed or from high speed to low speed. At this time, as long as the control handle is pushed out or pulled back to any gear position, the hoist (winch) can stably operate at the corresponding speed of the position 3 When the deceleration control hoist (winch) runs to the deceleration point (which can be set by PLC), PLC will give the deceleration signal, JSJ will act, the deceleration bell will ring and the deceleration indicator light will be on, causing the winch driver's attention. At the same time, the winch will automatically decelerate to the last two or three gears; After receiving the deceleration signal, the winch driver shall, according to the operation experience, retract the operating handle gear by gear to graally decelerate the hoist (winch) and make the motor decelerate to the crawling speed. When the hoist (winch) runs to the terminal position, the brake handle and operating handle shall be quickly pulled back to the zero position. When the hoist (winch) is running fast to the end point, the adjustable mechanical brake can be used to rece the speed until it runs to the end point 4 Speed limit protection circuit when the hoist (winch) enters the deceleration stage, on the one hand, PLC will automatically rece the gear, on the other hand, it will speed limit according to the speed given curve. In the deceleration stage, more than 10% PLC will brake safely 5 When the hoist (winch) enters the stage of constant speed operation, the voltage signal detected by the tachometer generator, on the one hand, is sent to the PLC through the transmitter for processing, and 15% of the rated speed PLC is used for safety braking; On the other hand, the over speed protection signal is given by setting the over speed relay GSJ. One signal of GSJ enters the hardware safety circuit for safety braking, and the other signal enters the PLC for software safety circuit for safety braking. 2. When the hoist (winch) enters the stage of constant speed operation, a rotary encoder is installed beside the recer or low-speed shaft to detect the rope speed, which is processed by PLC, and 15% of the rated speed is used for safe braking. Free paper website: http://www.xoock.com

4. Ore powder generally refers to the material proced after crushing and processing the mined ore, such as iron ore powder. It refers to the ore powder with different iron content proced after crushing and ball milling magnetic separation of different types of iron ores, such as limonite and magnetite. The iron content of ordinary ore powder is 60-68%, and that of super concentrate powder is 70-72%, while the relative iron content of iron powder is higher than that of ore powder, It is a kind of granular iron powder with high grade, which can be obtained by different processing methods, such as rection, water or gas atomization, mechanical crushing, electrolysis, molten salt decomposition and evaporation condensation

5. The speed of the separator is low, or the screen of the mill is damaged, or there is more steel slag in the slag. Increase the speed of separator and rece the output.

6. Commercial mortar has developed rapidly in China in recent years because of its many unique advantages. Thermal insulation mortar is an important type of commercial mortar. With the continuous improvement of building energy saving requirements, thermal insulation mortar has developed rapidly in recent years
for thermal insulation mortar, the thermal insulation performance is closely related to the bulk density. Generally speaking, the lower the bulk density, the better the insulation performance. However, the decrease of bulk density will also lead to the decrease of strength. How to balance the contradiction between bulk density and strength is the key problem of preparing insulation mortar
fly ash is a kind of instrial waste collected from the chimney of burning power plant, and mineral powder is a kind of instrial waste proced when smelting iron ore. these are the most commonly used admixtures. In recent years, they have been widely used in the proction of concrete and ordinary mortar, playing the role of improving the comprehensive performance of cement-based materials, recing proction costs and recing environmental load. It will also have a greater impact on the strength and bulk density. Yili [1] thinks that fly ash composite thermal insulation mortar not only has high strength, good rability, light volume weight, high bonding strength, but also can achieve the function of thermal insulation. In this chapter, the relationship between strength and bulk density will be established through experiments to find out the most suitable amount of fly ash and mineral powder< Cement: the cement used in the experiment is ordinary portland cement with 32.5 strength grade
2. Fly ash: Grade III fly ash from Kaifeng power plant
3. Ore powder: Grade I ore powder from Beijing Shougang
4. foam ball: raw granule, particle size less than 5mm. < The ratio of BR / > 3 test method
3.1 is determined by the ratio of water to binder ratio of 1:2, the dosage of rubber to 500kg/m3 foam ball, the two percentages of fly ash and mineral powder to replace cement, the mass percentages are 0%, 10%, 20%, 30%, 40%, 50%, respectively.
3.2 for mortar preparation and test, the raw materials weighed accurately are mixed evenly, and then the mortar is shaped according to GB / t17671-1999 "test method for strength of cement mortar (ISO method)", the formwork is removed 24 hours, and then it is put into the standard curing box for curing until 3 days, 7 days, 28 days and 90 days, and the flexural strength and compressive strength of the insulation mortar at each age are measured, The 28 day bulk density measurement is to take the specimen out of the curing box after 24 days of curing, soak it in water for 4 days, wipe the surface with a wet cloth, measure its wet bulk density, and then dry it to the balance weight to measure its dry bulk density< Results and analysis
4.1 the influence of slag powder on the strength and bulk density of thermal insulation mortar
1. Basic rules:
(1) the flexural and compressive strength of mortar will decrease with the increase of mineral powder content in the early stage (3D, 7D), but there is an extreme point when the mineral powder content is 10%
(2) in the later stage (90d), the mortar strength increases rapidly, and with the increase of mineral powder content, the mortar strength first increases and then decreases. The 90d strength reaches the maximum when the mineral powder content is about 30%
(3) the content of mineral powder has little effect on the dry and wet bulk density of mortar, which is lower at 30%
2. results analysis:
(1) mortar strength depends on the quantity and nature of cement slurry at the contact point of foam ball. The more cement slurry, the stronger the contact point; The higher the strength of cement slurry is, the stronger the contact point is
(2) in the early stage (3D, 7D), with the increase of mineral powder content, the amount of cement slurry increases, but the strength of cement paste decreases, and the effect of the latter is stronger than the former, so the strength of mortar decreases with the increase of mineral powder content. Among them, the 7d strength increases when the mineral powder content is small, which is mainly e to the better gradation of mineral powder particles and cement particles, so the compactness is better, which also corresponds to the increase of bulk density when the mineral powder content is 10%
(3) in the later stage (90d), the activity of mineral powder is stimulated, and the calcium hydroxide released from cement hydration becomes the basic activator of slag composition, and interacts with the active components in slag to continue to proce hydrated calcium silicate, hydrated calcium sulphoaluminate or hydrated calcium sulphoferrate, which promotes the continuous hydration of slag and cement, and when the dosage is 30%, the hydration of slag is promoted, The amount of calcium hydroxide released is just equal to the active component in slag, and the hydration of slag powder is relatively complete, making the highest strength
(4) although the volume of cement slurry increases, the weight does not increase. Moreover, the cement paste is filled in the void of the foam ball without increasing the total volume. Therefore, mineral powder has little effect on the bulk density of mortar< There are some differences between the thermal insulation mortar with slag powder and the thermal insulation mortar with fly ash, mainly in the following aspects:
the activity of slag powder is higher, so although the strength of thermal insulation mortar with slag powder is lower in the early stage, it can grow faster in the later stage, The later strength is even higher than that of ordinary portland cement insulation mortar. Compared with slag, the glass content of fly ash is lower, the silicon content is higher, and the [SiO4] 4 - is mainly high polymer, so the disintegration of glass in fly ash is more difficult. In the malignant environment of cement hydration, the disintegration speed is very slow. With the increase of fly ash content, the early strength of thermal insulation mortar decreases greatly, However, the late strength (after 28d) increased
slag and fly ash are compounded in different proportions, hoping to make up for their respective defects and obtain better mortar performance through their performance differences, that is, to achieve the effect of complementary advantages. Whether the strength of thermal insulation mortar with composite slag and fly ash can exceed that of single mixing is the main index to judge whether the composite slag and fly ash can show complementary effect
when the water binder ratio is 0.5, the cement content is 300g, and the total content of fly ash and mineral powder is 40%, the strength of the composite is obtained. It can be seen clearly that the strength of D22 and D13 mortar at the hydration age of 28 d and 90 d is higher than that of D40 mortar and D04 mortar. It can be considered that when the total content of slag and fly ash is 40%, the composite of slag and fly ash can proce complementary effect
the fact that composite cement has complementary advantages has been recognized by many researchers, but there is a lack of in-depth research on the mechanism and conditions of complementary advantages
as there are not only clinker particles, but also slag and fly ash particles in the fine particles of cement, their activity and hydration rate are different. In the hydration process of cement, they can be used as active components to increase the formation of hydration procts, or as active micro aggregates to rece the number of macropores and porosity, so as to contribute to the improvement of strength
4.2.3 orthogonal test the size of the test piece is 40mm × 40mm × In order to investigate the influence of fly ash and slag powder on the flexural strength, compressive strength and bulk density of thermal insulation mortar, and to seek the best mix proportion, orthogonal experiment was carried out. According to the data processing theory of orthogonal experiment, taking fly ash and slag powder as two factors, the orthogonal experiment of two factors and three levels is designed, in which the factors are the mass percentage of substitute cement< Results of 90 day orthogonal test: for the 90 day bending strength, the order of the factors in the order of range is as follows:
main → secondary B, a, a × B It can be seen that the best match is B1a1, followed by b2a3 and b2a2
for the 90 day compressive strength, the order of factors in the order of range is:
main → secondary B, a, a × B It can be seen that the best match is b2a3, followed by b2a1 and b3a2
2. Bulk density analysis
for wet bulk density, the primary and secondary order of factors in the order of range is:
primary → secondary a × B，A B It can be seen from the table that the best match is a2b3, followed by a3B1 and a3b2
for dry bulk density, the order of factors in the order of range is:
primary → secondary a × B，A，B It can be seen from the table that the best match is a2b2, followed by a3B1 and a3b2. The range R is used to measure the effect of the corresponding factors in the test. The factors with large range show that the three levels of the evaluation index have great differences, which are usually important factors, while the factors with small range are often unimportant factors. In this experiment, the order of the factors is b > a. Factor B is the main factor because of its wide range of fluctuation. The combination with the highest strength is a2b2, and the combination with the lowest weight is a2b2. The primary and secondary effects of the factors considered in the above four combination conditions can be obtained by direct observation and calculation; Comprehensive balance method & quot; The optimal combination condition is a2b2, that is, a = 30%, B = 20%
conclusion the purpose of this paper is to study the strength and bulk density of slag powder and fly ash thermal insulation mortar at different ages according to the application needs of thermal insulation mortar, and to determine the relevant parameters for the application of slag mortar in engineering, The main research conclusions are as follows:
(1) the addition of slag powder makes the strength of thermal insulation mortar decrease in the early stage, and increase until the later stage, catching up with or even exceeding the cement mortar without slag
(2) the content of mineral powder has little effect on dry and wet bulk density of mortar
(3) the law of fly ash is similar to that of mineral powder, but its strength is lower than that of thermal insulation mortar< (4) fly ash has little effect on the bulk density of mortar
(5) slag powder and fly ash have complementary effect on the strength of thermal insulation mortar
(6) through orthogonal test, the newly developed thermal insulation mortar mixed with slag powder and fly ash is determined for 90 days, and the optimized mixing amount is 20% of mineral powder and 30% of fly ash respectively, so as to optimize all levels of cementitious materials and activate the activity, so as to optimize the strength and capacity of thermal insulation mortar
(7) the thermal insulation mortar with mineral admixtures not only has good strength, but also has remarkable market economy.