The standard of Ball mill and Rod mill

1. Scope

This standard specifies the following scope of ball mills and rod mills, their type and basic parameters, technical requirements, test methods, inspection rules, marking and instructions for use, packaging, transportation and storage.

This standard applies to ball mills and rod mills(Hereinafter referred to as mills) for grinding ores, rocks and other suitable grinding materials of various hardness in wet and dry processes.

2. Type of mills and basic parameters

2.1 Type of mills

2.1.1 Mills are divided into ball mills and rod mills according to different grinding media; ball mills are divided into grate type and overflow type according to discharge form, and grate type ball mills are divided into dry type and wet type. The structure type is shown in Figure 1, Figure 2, Figure 3, Figure 4 and Figure 5 respectively, and this figure does not determine the specific structure. Among them, Figure 1 discharge end cover structure is recommended for grate ball mill with diameter no more than φ3200mm, and Figure 2 discharge end cover structure is recommended for grate ball mill with diameter no less than φ3600mm.

2.1.2 The transmission type of the mill is divided into synchronous motor drive, asynchronous motor drive and gearless drive. According to the motor power, synchronous motor drive and asynchronous motor drive are divided into single drive and double drive. For the single drive mill, the mill arrangement type is divided into left and right side (facing the feed side in the direction of material flow, the main motor on the left side of the cylinder is left side mill, the main motor on the right side of the cylinder is right side mill). The specific type is shown in Figure 6, Figure 7, Figure 8, Figure 9, Figure 10.

2.2 Model

2.2.1 Ball mill model number indication method

2.2.2 Rod mill model number indication method

2.3 Basic parameters of the mill

The basic parameters of the mill shall conform to the provisions of Table 1, Table 2, Table 3 and Table 4 respectively
Table 1 Wet type grate ball mill basic parameters

Table 2 Dry type grate ball mill basic parameters

Table 3 Overflow type ball mill basic parameters

Table 4 Wet rod mill basic parameters

3. Technical requirements

3.1 Basic requirements

3.1.1 The mill shall conform to the provisions of this standard and be manufactured in accordance with the drawings and technical documents approved by the prescribed procedures.
3.1.2 The raw materials, purchased parts and processing, assembly, installation and other technical conditions, which this standard does not specify, should be in line with national standards and relevant industry general standards.
3.1.3 Operating conditions: Ambient temperature range -5°C~40°C; Operating system: Continuous.
3.1.4 The unannotated tolerance of linear dimensions on the drawing:
a) cutting parts should comply with GB/T 1804-2000 m level;
b) non-cutting parts of the welded parts should comply with the relevant provisions of JB/T 5000.3-2007 in 7.3.
3.1.5 The welded parts should comply with the relevant provisions in JB/T 5000.3
3.1.6 Casting steel parts should comply with the relevant provisions in JB/T 5000.6
3.1.7 Ductile iron parts should comply with the relevant provisions in GB/T 1348.
3.1.8 Forging parts should comply with the relevant provisions in JB/T 5000.8
3.1.9 High manganese steel casting parts should comply with the relevant provisions in GB/T 5680
3.1.10 Casting iron parts should comply with the relevant provisions in JB/T 5000.4

3.2 Complete equipment performance requirements

3.2.1 The main technical parameters of the mill shall conform to the provisions of this standard and be adapted to the requirements of the actual system process.
3.2.2 For mills with cylinder diameter greater than or equal to Φ2700 mm series, hybrid main bearings are recommended; for mills with cylinder diameter greater than or equal to Φ5000 mm series, hydrostatic main bearings are recommended; for mills with cylinder diameter greater than or equal to Φ7300 mm series, sliding bearings are recommended. Mills with cylinder diameter less than Φ4000mm can also use rolling bearings.
3.2.3 The temperature rise of the main bearing return oil under normal working condition should not be higher than 15℃, and the maximum return oil temperature should not be higher than 55℃.
3.2.4 For mills with cylinder diameter less than or equal to Φ4000mm and power less than or equal to 1600kW, grease lubrication is recommended for pinion bearings; for mills with cylinder diameter greater than Φ4000mm and power greater than 1600kW, thin oil lubrication is recommended for pinion bearings.
3.2.5 The noise pressure level of the mill during no-load operation should not exceed 90 dB(A).
3.2.6 The complete mill shall include: main machine, main motor, spray lubrication device, main bearing lubrication station and low voltage centralized electric control equipment, etc. Synchronous transmission shall also include clutch, asynchronous transmission shall include reducer and coupling, and gearless transmission shall include brake. For mills with cylinder diameter greater than or equal to Φ2700mm, the necessary auxiliary machines (such as slow speed drive, jacking device, etc.) should be provided as required.
3.2.7 Mill lubrication device should be reliable operation, if equipped with lubrication station, the oil pump motor and the main motor should have an electrical interlock device, when the lubrication system has failure and can not work properly, it should send a signal to ensure that the main motor automatically stop, and it also should be equipped with alarm signal device for oil temperature, oil pressure, oil volume, differential pressure; lubrication system should be equipped with safety valves, manometers, thermometers and other safety devices.
3.2.8 The inclination of the return pipe is recommended to be 1 : 20~1 : 6

3.3 Safety requirements

3.3.1 The rotating part of the transmission shall be equipped with protective cover, and the user shall set protective rails around the rotating parts.
3.3.2 The requirements for protective grounding, insulation resistance and voltage test of the electrical equipment used in the mill shall conform to the relevant provisions of GB 5226.1.

3.4 Main parts requirements

3.4.1 Main bearing and slide bearing material should not be lower than the provisions of Table 5 mechanical properties. The main bearing lining of the mill with cylinder diameter less than φ5500mm series is recommended to use tin-based casting bearing alloy, the alloy material should not be lower than the provisions of GB/T 1174 on ZSnSb11Cu6, the alloy should be firmly attached, there should be no shelling phenomenon. The main bearing lining of the mill with cylinder diameter greater than or equal to φ5500mm series is recommended to adopt the copper bush structure, and the material is recommended to adopt copper-based casting bearing alloy, and the alloy material should not be lower than the provisions of Table 5 mechanical properties. Sliding bearing lining using tin-based casting bearing alloy, alloy material should not be lower than the provisions of ZSnSb11Cu6. If the main bearing adopts rolling bearing, it will be executed according to the technical conditions of rolling bearing.

3.4.2 Cylinder steel plate material should not be lower than the provisions of GB/T700 on the mechanical properties of Q235A; the tensile strength of the welding rod used should not be lower than 420 MPa.

3.4.3 The welding seam of the cylinder is not allowed to pass through the manhole and screw hole, and the distance between the welding seam and the edge of the hole is not less than 75 mm, and the quality of the welding seam should not be lower than the BS level and BK level stipulated in JB/T 5000.3- -2007.
3.4.4 The cylinder should be welded to eliminate the welding stress after welding.
3.4.5 The maximum permissible value of the surface roughness parameter Ra at the inlet and outlet hollow shaft journals is 1.6 μm. The maximum permissible value of the surface roughness parameter Ra at the R-zone is 3.2 μm.
3.4.6 Inlet and outlet end covers and hollow shaft materials should not be lower than the provisions of Table 5 mechanical properties, processing surface for ultrasonic flaw detection, should not be lower than GB/T 7233. 1 a 2009 level 2 provisions, R area for magnetic particle inspection, should not be lower than GB/T 9444 – – 2007 level 2 provisions.
3.4.7 The liner material allows the use of metal liner, rubber liner and magnetic liner. Metal liner and the cylinder and end cover should be equipped with rubber washers to reduce the impact of the grinding media on the cylinder and end cover, also to reduce the slurry abrasion on the cylinder and end cover.
3.4.8 Pinion or shaft gear
Pinion or shaft gear material mechanical properties should not be lower than the relevant provisions of Table 5, tooth surface hardness should be minimum 30 HB higher than the ring gear tooth surface hardness, processing accuracy should be consistent with the provisions of GB / T 10095.1 and GB / T 10095. 2.
3.4.9 Ring gear
The mechanical properties of the ring gear material should not be lower than the relevant provisions of Table 5, and the machining accuracy should be in accordance with the provisions of GB/T 10095. 1 and GB/T 10095. 2; the thickness of the wheel rim should be uniform.

Table 5 Minimum mechanical properties of main parts

3.4.10 After the cylinder assembly, the radial and axial swing should not be greater than the provisions of Table 6

Table 6 End cover radial runout and axial oscillation tolerance

3.4.11 The corresponding fitting sizes of the wearing parts (various liners, spoon heads, pinions, etc.) or spare parts (inlet and outlet pipes, ring gears, reducer gears, etc.) of the mill should be interchangeable.
3.4.12 The performance of the speed reducer shall conform to the provisions of JB/T 8853.

3.5 Assembly technology requirements

3.5.1 The main bearing should be in uniform contact with the bearing base plate from all sides.
3.5.2 The spherical surface of the main bearing with spherical bushing structure must be matched with milling, the spherical surface should be in good contact and flexible action; the main bearing with drum surface structure does not need to be matched with milling.

3.5.3 Using cast bearing alloy material of the main bearing bushing need to make the cooling water channel, cooling water channel should be checked through the water, there should be no leakage phenomenon. Using cast copper alloy material of the main bearing bushing does not need to make cooling water channel.

3.5.4 After the mill is assembled, the clearance between the shaft bushing and the hollow shaft shoulder should be uniform, with a maximum deviation of not more than (0.08 X hollow shaft diameter)/1 000 mm.

3.5.5 The coaxiality error of the drive shaft and motor shaft (or reducer shaft) should not be greater than φ0. 3 mm, and the tilt deviation should not be greater than 1/1000.

3.5.6 The radial runout of the ring gear after assembly is not more than 0.125 mm per meter of pitch diameter, and the end runout is not more than 0.15 mm per meter of pitch diameter.

3.5.7 Large gear and pinion tooth side clearance should be in line with relevant industry standards.

3.5.8 For mills with the diameter less than φ5500mm, the contact spot of ring gear and pinion teeth should not be less than 40% along the direction of tooth height and 50% along the direction of tooth length; for mills with the diameter greater than or equal to φ5 500mm, the contact rate of ring gear and pinion teeth should not be less than 50% along the direction of tooth height and 70% along the direction of tooth length.

3.5.9 The arrangement of the wet mill liner inside the cylinder shall not constitute an annular gap. The annular gap between end liner and cylinder liner, end liner and inlet and outlet pipe shall be plugged with materials such as wood wedge (wet operation), iron wedge or cement (dry operation). The gap between the liner and the liner is not more than 10 mm.

3.6 Electrical control system

The mill should be provided with a complete set of low-voltage electric control device to complete the following control functions,
a)Sequential logic control of mill start-up and shutdown
b)Control, protect and interlock the main and auxiliary machines such as main motor, clutch or reducer, lubrication station, main bearing, slow speed drive device and injection lubrication device to realize mill fault alarm or shutdown to ensure continuous and long-term safe operation of the mill
c)Provides power to the supporting auxiliary machines and control cabinets.

3.7 Painting

The equipment should be painted before packaging and transportation, and the technical requirements and inspection of painting should be in accordance with the relevant provisions of JB/T 5000.12

4 Test method

4.1 Visual inspection of the appearance, there should be no obvious defects.
4.2 When the mill is empty running the noise should be measured according to the method specified in GB/T 3768.
4.3 When the mill is tested in empty running, it should meet the following requirements
a)Continuous empty running no less than 4 hours
b)The temperature rise of the main bearing return oil and the maximum return oil temperature shall be in accordance with the provisions of 3.2.3;
c)The lubrication of each lubrication point should be normal, no oil leakage;
d)The noise shall be in accordance with the provisions of 3.2.5
e)No significant change in main motor current.
4.4 The load operation test is carried out after passing the empty load. Before operation, the mill cylinder is loaded with 20%-30% of the maximum load of steel balls (rods) and materials, and 10% is added every 30 min to reach full load, with 24 hours of continuous operation it should reach
a)The mill should work smoothly and without abnormalities
b)No leakage at the screw holes, manholes and flange surfaces of the cylinder
c)The temperature rise of the main bearing return oil and the maximum return oil temperature shall be in accordance with the provisions of 3.2.3;

5 Inspection rules

5.1 Types of inspection

The inspection is divided into factory inspection and type inspection.

5.2 Factory inspection

5.2.1 Each mill shall be inspected by the quality inspection department of the manufacturer before leaving the factory, and the factory shall be accompanied by documents proving the qualified quality of the product
5.2.2 The factory inspection items are 3.2.3, 3.2.5, 3.4.10, 3.5.1, 3.5.2, 3.5.8, and 4.7

5.3 Type inspection

5.3.1 One of the following circumstances, the type test should be carried out:
a)new product prototype identification or old product transfer production;
b)formal production, product structure, materials, processes have changed significantly, which may affect the performance of the product;
c)normal production after the regular inspection;
d)resuming production after a long hiatus;
e)factory inspection results and the last type test has a large difference;
f)the national quality supervision and inspection agencies to type test requirements.
5.3.2 Type inspection should include all the requirements of this standard.
5.3.3 Type inspection should be taken 1 set mill from the factory inspection of qualified products. If the test fails, the sample should be doubled for re-testing. If the re-inspection is qualified, the batch of products is judged to be qualified. If there is still 1 set of unqualified, the batch of products will be judged as unqualified products.

6 Signage and Operating Instructions.

6.1 Each mill shall have the product label fixed in a conspicuous and appropriate location. The label shall conform to the provisions of GB/T 13306 and shall indicate the following
a) the name and address of the manufacturer;
b) Product name and model;
c) the main technical parameters;
d) product implementation standard number;
e) the date of manufacture and factory number.
6.2 The manual of the mill should comply with the provisions of GB/T 9969.
6.3 The packaging mark of the mill should comply with the provisions of GB/T 191.

7 Packaging, transportation and storage

7.1 The packaging of the mill shall conform to the provisions of JB/T 5000.13.
7.2 The mill is divided into closed packaging, bare and bundled. The parts and components shall be firmly fixed in the box.
7.3 The exposed processing surface of the mill shall be anticorrosive and wrapped with oil paper or plastic film, and the anticorrosive period shall not be less than 1 year.
7.4 The outer wall of the closed box shall be clearly marked with words and conform to the provisions of 6.3, including:
a) the receiving station and the name of the receiving unit;
b) the shipping station and the name of the shipping unit;
c) contract number and product name, model;
d) gross weight, net weight, box number and external dimensions;
e) lifting operation mark and storage and transportation icon.
7.5 The naked package should be clearly marked in the text, and in accordance with the provisions of 6.3.
7.6 The following technical documents are included with the package:
a) product quality certification documents;
b) product manual;
c) packing list and set of shipping details;
d) General assembly diagram, installation base diagram and installation parts diagram;
e) catalog of wearing parts.
7.7 The mill shall have safety measures to prevent deformation and crushing during transportation.
7.8 The packaging of the mill shall be in accordance with the land or waterway transportation requirements.
7.9 Storage of the mill shall be in accordance with the following requirements:
a) The mill shall be stored at a temperature of not less than 5°C and shall not be subject to direct sunlight and staining by lubricating oil;
b) The storage room or shed should be ventilated to prevent rain and snow and direct sunlight;
c) bare and bundled parts should be placed singly and not allowed to be placed in yards.
7.10 The mill should be maintained once every year of storage.

Note: This standards are originally translated and composed by Henan Deya Machinery Company Limited, reference based on GB/T 25708-2010 which was released on 23rd, December, 2010