Cylindrical energy saving grid ball mill is one of energy saving mills developed by Xinhai, which is easy to start and saves 20-30% energy. It is lined grooved ring plate which increases the contact surface of ball and ore and strengthens the grinding. In addition, the large ore outlet increases the capacity. The particle size of grinding product is coarse, so it is applied in first grinding.
The main part of cylindrical energy saving grid ball mill is cylinder with small diameter and large length rotating slowly by the transmission device. The material is fed from the cylinder inlet and grinded by the impact of steel ball and ore and self-grinding. Due to the continuously feeding material, the pressure pushes material to the outlet and the grinded material is discharged from the cylinder outlet. In wet grinding, material is taken out; in dry grinding, the material is taken out by air. The grid installed in the outlet of mill is relied for forced discharge. Low pulp surface in cylinder reduces the ore over-grinding, and prevent the steel ball out. Under the same production conditions, production capacity of grid mill is larger than overflow mills. Both ends of the cylinder body adopt rolling bearing instead of the sliding bearing, which is more energy-saving.
Cylindrical energy saving grid ball mill consist of feeding part, discharging part, rotary part, transmission part (reducer, small gear, motors, electrical control) and other major parts. Hollow shaft is steel castings, and the liner is detachable. Rotary gear is processed by casting hobbing. The cylinder is lined wear-resistant liner plate with good resistance to wear. This machine works stably.
Ball mill is a kind of grinding equipment commonly used in the concentrator, which accounts for a large proportion in the capital investment and production cost of the whole concentrator. Besides, it also has a great impact on the final economic and technical indicators of the concentrator.
According to the different grinding conditions, the ball mill can be divided into wet ball mill and dry ball mill. Before selecting the type of ball mill, we should know about the difference between the wet ball mill and dry ball mill, then make a targeted choice.
The wet ball mill and dry ball mill are basically the same in shape and component structure. The cylinder is cylindrical. The component structure mainly includes the feeding part, the discharging part, the rotary part, the transmission part (reducer, transmission pinion, motor, electric control), etc.
The difference between the two is that the structure of the wet ball mill is relatively simple, without too many auxiliary accessories, and the horn-shaped discharge port and the double helix built-in ore discharging facilities are more convenient for discharging. The structure and structure of dry ball mill is more complex with straight cylinder discharge port, air suction device, dust pipe and dust collector.
The working principle of the wet ball mill is to use the transmission machinery to drive the barrel for rotating, and the material is fed from the ore feeing port. Under the action of centrifugal force, the steel ball, material and the lining plate in the barrel body strike and grind among them, so as to complete the material grinding. In this process, the wet ball mill needs to be matched with water to achieve the appropriate pulp concentration. The qualified materials are discharged from the discharging port, while the unqualified materials are returned to the wet ball mill for regrinding.
In the operation process of dry ball mill, the material is fed into the hollow shaft from the feeding device, and the hollow shaft sends the material into the first warehouse by the uniform spiral movement. The warehouse is equipped with the ladder lining board (or corrugated lining board) and steel balls with different specifications.
The wet ball mill can achieve continuous production, has the stronger adaptability to the material, large crushing ratio, easy to adjust the abrasive fineness, high grinding efficiency, low water content requirement of the ore and simple material transport device. Its investment cost is about 5%-10% lower than the dry ball mill.
The dry ball mill adopts grate plate forced-discharging mode, its discharging is smoother, and there is no rise grinding phenomenon, the cylinder doesnt need cooling, and the material has the small wear to the on the lining plate and medium in the fine grinding process. Besides, it has long service life and low failure rate. But because of its barrel reasons, the dry ball mill occasionally forms the dead corner, the material in the dead corner is not easy to be ground.
When the material meets the water will not affect the final product quality, the requirements on the selected ore particle size are fine, and the separation requirements are high, then the material can adopt the wet ball mill.
The wet ball mill has a wide range of applications, can be used to treat all kinds of metal and non-metallic minerals, such as gold ore, silver ore, copper ore, iron ore, phosphate ore, molybdenum ore, feldspar ore, fluorite ore, etc.
If the material has physical or chemical reaction with water (such as cement, marble and other building stones), or the material needs to be stored or sold in the form of grinding, the dry ball mill can be considered.
Here are the four major differences between wet ball mill and dry ball mill and how to choose the two. Only by identifying the grinding method suitable for the material, can we ensure the quality and efficient operation of the ball mill. The wet ball mill and dry ball mill have their own advantages, we still make the rational choice according to the properties, characteristics of the material, the requirements for the product and the working environment.
As one of the most important mineral processing equipment in the concentrator, ball mill machine plays an important role, which not only determines the technical index of the whole mineral processing flow, but also accounts for most of the investment cost and energy consumption. Therefore, it is very important to achieve the high-efficiency and energy-saving of the ball mill machine.
Xinhai Mining has been focusing on the design and development of ball mill machine for more than 20 years, and made numerous technical achievements in the research and development of ball mill machine. According to the specification of ball mill machine and customer needs, Xinhai Mining can customize the various aspects of ball mill equipment, making it achieve high-efficiency, low consumption and energy-saving.
At present, the drum speed of many ball mill machines is mostly 17r/min~32r/min, and the running speed of the small ring is mostly 120r/min~200r/min. The current ball mill generally adopts the drive mode that the asynchronous motor drives the small gear ring after the speed reduction of the reducer. But problems do exist with this mode, such as low efficiency, large footprint, mass maintenance task, high vibration noise and large starting impact. Aiming at these problems, Xinhai Mining re-innovated the drive system of the ball mill machine, and replaced the original drive system with the drive system of permanent magnet synchronous variable-frequency and variable-speed motor drive system.
Starting from the system point of view, the dedicated permanent magnet synchronous variable-frequency and variable-speed motor of Xinhai ball mill machine no longer only takes the motor as a standard part, but organically combines the motor, transmission mode and intelligent control to improve the motor efficiency and transmission efficiency while driving on demand, so as to achieve higher driving efficiency, and contribute to the realization of green mine.
Among them, the dedicated permanent magnet synchronous variable-frequency and variable-speed motor of Xinhai ball mill machine adopt vector control variable frequency drive, the rotor adopts high-performance nd-fe-b permanent magnet materials, which is featured with compact structure, large starting torque, low speed, small start impact, high efficiency, strong reliability, low noise, energy conservation, environmental protection, convenient installation and maintenance. It is a high-efficient and energy-saving motor in line with national policy.
(1) Cancels the deceleration link of the reducer, which reduces the intermediate transmission link, improves the equipment operation rate, decreases the equipment operation cost, and improves the site environment with low noise;
The motor is equipped with windings and bearing temperature sensors to monitor the running status of the unit in real-time, which has the abilities of fault early warning, self-care in an emergency and self-protection. The dedicated permanent magnet synchronous variable-frequency and variable-speed motor of Xinhai ball mill machine can eliminate the deceleration links of hydraulic coupler, reducer and belt pulley, reduce the floor area and increase the space of safe passage.
The frequency converter of the dedicated permanent magnet synchronous variable-frequency and the variable-speed motor is an intelligent control device integrating feedback, control, drive, communication and protection, which is more convenient to realize the Internet of Things, remote monitoring and can improve the degree of automation.
The dedicated permanent magnet synchronous variable-frequency and variable-speed motor of Xinhai ball mill machine can eliminate the deceleration links of hydraulic coupler, reducer and belt pulley, avoid the environmental pollution caused by reducer oil leakage. At the same time, it can avoid the noise caused by the wear of asynchronous motor cooling fan and reducer, greatly improve the environmental friendliness of the site.
Improve the efficiency of the motor itself. The dedicated permanent magnet synchronous variable-frequency and variable-speed motor of Xinhai ball mill machine has the incomparable high efficiency and high power factor. According to the difference of original motor model, power level and load rate, the electric saving rate of the motor is 5%-10%, and there is no brush slip ring and other vulnerable structures.
Improve the transmission efficiency. The dedicated permanent magnet synchronous variable-frequency and variable-speed motor of Xinhai ball mill machine can eliminate many transmission links, such as the reducer, belt pulley, which can improve the transmission efficiency by 5%~15%, reduce the maintenance cost.
Reduce line loss. The dedicated permanent magnet synchronous variable-frequency and variable-speed motor of Xinhai ball mill machine has a high power factor of over 0.96, which can greatly reduce the line current and reduce the line loss of 2%~4% rated power.
The dedicated permanent magnet synchronous variable-frequency and variable-speed motor of Xinhai ball mill machine can save the deceleration link, save the brush slip ring structure of wound rotor asynchronous motor, cancel the high failure rate and maintain the reducer and slip rings in the long term, greatly reduce the maintenance amount and maintenance cost, eliminate the lubricating oil cost of reducer, the maintenance cost of FCB and depreciation expense of reducer.
Adopt the vector-controlled variable frequency drive can improve the starting torque, reduce the starting current, and thus reduce the impact of the power grid and ball mill equipment, improve the service life of each mechanical part. At the same time, it cancels the reducer and carbon brush slip ring structure with a high failure rate, improves the equipment operation rate by 0.5%~1%, thus increasing the operation output and increasing the profit.
The ore handling capacity, ore hardness, particle size and ball mill liner wear will cause the actual speed to deviate from the designed speed. The dedicated permanent magnet synchronous variable-frequency and variable-speed motor of Xinhai ball mill machine adopt the variable frequency drive to change the operating frequency for adjusting the load speed, thus improving the grinding efficiency of the ball mill machine and greatly reducing the invalid energy consumption.
Mineral processing equipment is the key to realize the mineral processing index and economic indicator. Xinhai technology personnel of mechanical design institute can provide customers with a series of mineral processing equipment according to the equipment requirements put forward by the mine research institute and mine design institute, which can enable customers to fully enjoy the one-stop services, including "mineral processing test, mineral processing technology, equipment selection, mine design, equipment customization", combine with the complete process, increase the yield, reduce the energy consumption, prolong the equipment stable operation time, help the global customers save the investment cost and improve the beneficiation indexes.
In the future, Xinhai Mining will also insist on technological innovation with the equipment quality, takes the strong technical strength as the core competitiveness, high quality of mineral processing equipment as the quality guarantee, continuously consolidate our innovation and development ability. We will try to set the reasonable technological process for the world's mines, choose the appropriate mineral processing equipment, thus building the green mine with the ideal benefit!
The new grooved annular liner increases the ball ore contact surface, strengthens the grinding effect, and has the ability to lift the ore, reducing energy consumption; the large double-row spherical roller bearing design can reduce the friction.
An air inflation mechanical agitation floatation cell with slurry suction, which is featured with strong agitation force, good air spreading effect, uniform mixing of slurry and air, less sedimentary of tailings, low turnaround speed and low power consumption.
This thickener is a new type thickening equipment independently developed by Xinhai. The thickener is equipped with additional deaerating tank, which can eliminate the solid particles attaching to the bubbles.
A double stages slurry pump with head of 70m. It is lined with high wear-resisting rubber, whose abrasion resistance index is up to 128%. Double Stages Slurry Pump is a rare rubber slurry pump with integrated effects of wear-resisting, anticorrosion and high head.
The Mongolia 1,000t/d gold mineral processing plant was an EPC+M+O project. Xinhai worked to achieve high recovery of gold and other valuable minerals by cutting costs and maximizing benefits and attach great importance to workers safety, environmental protection and energy conservation.
Mexico 1500t/d copper lead zinc gold and silver polymetallic ore dressing project is a mining industry chain service (EPC + M + O) project undertaken by xinhai, which is solely undertaken by xinhai from design and research, manufacturing and procurement of complete sets of equipment, commissioning and delivery to mine management and operation.
The Guinea 6,000t/d gold mineral processing plant was an EPC+M+O project. The design scope covered construction drawings and workshop drawings and involved engineers in the fields of mineral processing, water supply and drainage, power, civil engineering and general layout.
The Malaysia 700t/d gold mineral processing plant was a symbol of Chine-Malaysia cooperation in the mining industry under the policy of The Belt and Road. The raw ore consisted of pyrite, quartz, calcite and mica, with gold being the valuable mineral. It had a gold grade of 4.70g/t, silver grade of 4.63g/t, iron grade of 20.10% and a sulfur grade of 20.55%.
The steel ball is the grinding media of the gold ball mill. In the working process, the steel ball will directly affect the grinding efficiency of the gold ball mill and even the working efficiency and product quality of the whole concentrator.
Below, we will introduce the steel ball in detail from its specification and quantity, material, ratio and grading to help you choose and add the steel ball correctly, so as to improve the grinding efficiency of the gold ball mill.
Generally, the diameter of the steel ball is between 20mm and 125mm. Among them, the diameter of the small steel ball is generally 40mm and a 60mm, the diameter of the medium steel ball is generally 80mm, and the diameter of the large steel ball is 100mm or 120mm. The diameter of the super large steel ball is 130mm-150mm.
Theoretically, when the filling amount of steel ball in the ball mill is 40%, the ball mill can obtain the ideal output. But in the actual production, the filling rate of the steel ball in the ball mill is mostly about 35%, that is, the volume of the steel ball in the gold ball mill is kept slightly below the horizontal centerline of the ball mill.
As the "consumable" in the grinding operation, the wear degree of the steel ball is different due to the different material. At present, the mainstream steel balls of the gold ball mill on the market mainly include casting steel balls and forged steel balls.
Casting steel balls are mainly low chromium casting steel ball, medium chromium casting steel ball and high chromium casting steel ball, whose hardness, impact value and breakage rate are related to the metallographic structure of steel. The higher the chromium content, the better the wear resistance of the steel ball.
Forged steel gold ball mills mainly include low carbon alloy steel ball, medium carbon alloy steel ball, high manganese steel ball, rare earth chromium molybdenum alloy steel ball. The impact toughness of the forged steel ball is large, not easy to deform, but the crushing rate is low.
When first enabled, the gold ball mill needs the large, medium and small steel ball for matching, and the steel mill ball for the first time should be added to 80% of the amount limit that the ball mill manufacturer of ball mill suggests. Because the gears of the ball mill need mesh after the installation, and the processing capacity of the ball mill is increased gradually, then the ball mill operator needs to observe the condition of gear meshing in two or three days. If all is going well, the ball mill operator can open the hole cover to add the remaining 20% of steel ball.
Usually, the small steel balls are used only in the first addition. When the ball mill is running normally, there will be reasonable friction between the steel ball and the steel ball, the steel ball and the ore, the steel ball and the lining plate of the ball mill, which makes the wear increase. The large steel ball is ground into small, and the medium steel ball is ground into the small steel ball, so there is no need to add the small steel ball under normal circumstances. However, if the particle size of the useful mineral does not realize the monomer separation, and the grinding fineness of the ball mill cannot meet the separation requirements (especially the flotation separation requirements), the appropriate amount of small steel balls can be added into the gold ball mill.
In addition, the ball mill steel ball is constantly worn in the operation, the ball mill operator must regularly make up the steel ball and maintain the load filling rate of the steel ball and reasonable ratio.
Determine the grading scheme of the steel ball usually starts from the first warehouse (namely the coarse crushing warehouse). For the multi-bin ball mill, the grading of the first bin is particularly important. According to the cross-gradation principle, the minimum diameter of the steel ball in the previous bin determines the maximum diameter of the steel ball in the next bin. It can be seen that the grading of the steel ball in the first warehouse actually dominates the grading of the steel ball in the other warehouses.
The upper limit of the ball diameter is determined according to the upper limit of particle size of the grinding material. The average diameter of the steel ball is determined according to the average particle size of the grinding material.
The composition proportion of each specification steel ball is set according to the proportioned principle of "small at both ends and large in the middle" for the grinding body and the distribution characteristics of material size,.
Calculate the average ball diameter of the mixed steel ball, and compare with the original average ball diameter of the steel ball, add the steel ball according to the proportion of the ball size. If the deviation is large, it is necessary to set the composition proportion of various steel balls and rematch the balls until the deviation is small.
The secondary grading method means to only select two different diameters of ball mill steel balls for grading. The diameter of the large steel ball depends on the particle size of the grinding material, and the diameter of the small steel ball depends on the size of the space between the large steel balls.
Usually, the diameter of small steel ball should be 13%-33% of the diameter of large steel ball. Generally, the small steel ball accounted for 3%-5% of the mass of large steel ball, and the incorporation amount of small steel ball shouldnt affect the filling rate of large steel ball in principle.
These are the main aspects of the steel ball involved in the grinding process: specifications and quantity, material, ratio and grading. For the concentrator, the selection and application of the steel ball involve many technical problems, it is suggested that the mine owners carefully analyze their own actual situation, determine the suitable steel ball for the concentrator through consulting the professional gold ball mill manufacturers, thus avoiding the unnecessary economic losses.
Ball mill grinder installation accomplishment according to the paper, to ensure all the components are at the right position. The complete installation process should be recorded and acceptance passed.
The bush should be installed on the sector block of lower bearing seat according to the rotation direction of ball mill. The bush should be revised according to the axial guide ring. The bearing seat seal should be installed correctly. The junction should be sealed by a sealant.
Ensuring that all the monitoring equipment are well-connected. The flow monitor, pressure switch and temperature sensor are set well. Oil pressure gauge, thermometer, accident button and interlocking device instructions are reliable.
Connecting with reducer and pinion coupling, and installing protecting mask. Start the lubricating oil system and cooling water system. Turn on the power of the ball mill, press the accident button to stop it, and check the main bearing, motor, and gears to determine whether the direction of rotation of the ball mill is correct. If there is no abnormality, start the ball mill to run for 8 hours.
When running empty, if the lubricating oil system is working normally and there is no oil leakage. The ball mill runs smoothly and there is no obvious noise. The vibration value of the main bearing, motor, and pinion does not exceed 0.1mm, and there is no obvious damage or hot phenomenon to all parts. The empty vehicle runs normally.
According to the ratio of ball mill, a certain amount of steel balls are added into the cylinder of ball mill grinder. Steel balls are added in batches. During operation, measure bearing temperature, current, and vibration intensity everywhere. After the installation of the ball mill is completed, start to run with load, add 70% of the specified load into the grinding material, and continue to run for more than 10 hours. During this process, the liner bolt joint should be fastened and check the bolt connection frequently to prevent the loosen.
During running with load, the ball mill grinder should satisfy the following requirements. The vibration of each part does not exceed 0.1mm; The current of the motor has no abnormal fluctuations; The running process is stable; The noise is small; The connecting bolts are tight, and the cylinder has good sealing.
The above is the whole installation and commission process of ball mill grinder. Xinhai Mining established the commission operation management service center to ensure the correct and favourable installation. Xinhai Mining insists on the service idea professional attitude wins the trusts of clients, helping clients to resolve problems and free from worries.
[Improvement]: Cylindrical energy-saving grid ball mill is lined with the grooved ring plate which increases the contact surface of ball and ore, strengthens the grinding effect, and has the ability to improve the ore with lower energy consumption.
Cylindrical energy-saving grid ball mill adopts the lined grooved ring plate which increases the contact surface of ball and ore , strengthens the grinding effect, and has the ability to improve the ore with lower energy consumption;
Cylindrical energy-saving grid ball mill design consists of feeding part, discharging part, rotary part, transmission part (reducer, small gear, motors, electrical control) and other major parts. The hollow shaft is steel castings, and the liner is detachable. Rotary gear is processed by casting hobbing. The cylinder of energy-saving ball mill is lined with wear-resistant liner plate with good resistance to wear. Therefore, the energy-saving ball mill machine works stably in the production.