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The reasonable gradation of grinding body is temporary and can only keep stable in a relatively long time, and the length of time is related to many factors, but the key is the grindability of the grinding body itself. How to judge whether the gradation of grinding body is reasonable can be judged synthetically according to the following aspects. (ma 'anshan longsheng wear-resistant materials co., LTD.) to see the mill running current. In the control range, low current, insufficient grinding quantity. The current is high, the load may reach the upper limit or the total load is reasonable, but the proportion of grinding part and grinding part used for grinding body is low. Grinding voice or grinding voice automatic control system display value; (3) the changes of relevant control parameters in the grinding machine load control system (including possible grinding sound, hoisting electromechanical flow or feed material quantity of roller press); (4) from the mill product output, product fineness value analysis. If the output is normal, the fineness is coarse, or the output is low, the fineness value is low, must adjust the coarse grinds the storehouse fine grinds the storehouse grinds the body proportion or the supplement. Low output, high fineness value (refer to screening residual), insufficient grinding body; (5), the use of materials varieties of particle size and processing performance changes (such as the use of fly ash or slag, there is a pre-grinding system, the equipment can not be synchronized with the mill operation or roller press in the discharge of edge material proportion increase, etc.) to timely adjust the grinding body gradation; 6, grinding machine operation thermal parameters, such as grinding machine inlet and outlet pressure, grinding machine ventilation; 7, stop grinding check material ball ratio, coarse grinding bin, normal surface steel ball exposed about half, grinding bin in the fine powder cover grinding body. Inspect the wear and blockage of the grate plate, observe the number of lining plates covered by the material ball, and check whether the grinding bin (without grading the lining plate) has the inverted grading status of the grinding body; 8, measuring material velocity. Screen analysis curve was made to measure the maximum height from the grinding surface to the mill barrel, and the ventilation area was measured. (9) pet-name, to observe the slag discharge from the slag mouth (sieve mill may not have or small); Attending, closed-circuit system cycle load value; ⑪, use different materials to do fineness value of admixture (surface) on the high side; ⑫, grinding material. The above material grinding body gradation is reasonable, is the combination of practice and theory, relying on experience and scientific methods both at the same time, to make a scientific judgment, to achieve high quality mill, high yield, low energy consumption and low grinding body consumption.

Basic types of mineral dressing and grinding machines? I. specification presentation method of grinding machine: Diameter length, denoted by symbol D L, if 2100 3600 ball mill, then its diameter is 2100mm and its length is 3600mm. Ii. According to the different media of the mill, it can be divided into: Medium for steel ball or cast iron ball, it is called ball mill; (2) medium for steel rod called rod mill; (3) the medium for gravel called gravel mill; (4) with their own ore as a medium called since the mill, since the mill and then add an appropriate amount of steel ball, constitute the so-called semi-automatic mill. Three, according to the different drainage methods are divided into: (1) overflow grinding machine, it is through the drainage end of the hollow shaft neck free overflow pulp, as shown in figure 1a; (2) grid ball mill, it is installed in the grid plate at the end of the row with the help of the pores for the row, see figure 1b; (3) surrounding discharge grinding machine, it is through the cylinder surrounding discharge, see figure 1c; (4) bar mill is divided into cylindrical overflow drainage and open low level drainage. Iv. According to the different shapes of the cylinder, it can be divided into: (1) short cylindrical grinding machine, L/D 1.0-1.5(L is the length of the mill, D is the diameter of the mill), self-grinding or semi-self-grinding is mainly short cylindrical; (2) long barrel mill, L/D 1.5. When L/D is 5-6, it is called pipe mill, which is divided into multiple rooms inside, called multi-chamber mill, generally used in the cement industry, (3) conical mill, China has stopped manufacturing the industrial mill, but the laboratory conical ball mill is widely used.

1. Conventional heat treatment process for high manganese steel Normal heat treatment: 1000 ~ 1100 ℃ heating, heat preservation or heating to 650 ~ 700 ℃ heat preservation for a period of time and then heating to 1050 ~ 1100 ℃ and then quenched. Large, of which the thickness disparity, complicated shape in 650 ~ 700 ℃ heat preservation for a period of time, is good for reduce the deformation and cracking, and of uniform thickness, shape, simple not easy cracking of the small,, no heat preservation is necessary. It is economical and effective to apply ordinary heat treatment to ordinary high manganese steel. 1) ZGMn13 heat treatment process of high manganese steel castings, high manganese steel ZGMn13 casting belongs to a small, simple thing, and no accumulation of heat, can be in the < 750 ℃ charging to medium and high speed up directly to the quenching temperature, the maximum thickness of 1.3 ~ 1.4 mm/min) (flame furnace heat preservation after quenching, austenitic organization can be a single. Simple large heavy thick pieces, accumulation of furnace, moderately complex parts, can at 650 ℃ or less charging, in 650 ~ 700 ℃ maximum thickness of 1.5 mm/min, and revise according to the thickness of accumulation, temperature after plastic deformation has been improved, appropriate USES faster heating up. Flame furnace temperature, heating rate can be used 250 ~ 250 ℃ / h; Furnace is relatively uniform, can use 300 ~ 650 ℃ / h; The temperature of the salt bath furnace is more even. Thickness of 50 mm ball mill lining board, electric furnace after 680 ℃ preheat, directly into the 1070 ℃, salt bath furnace, heat preservation for 15 min quenching, does not crack, and get a single austenitic organization. Practical experience shows that: the high-temperature insulation coefficient of flame furnace and electric furnace is calculated as 0.8min/mm; The single austenite structure can be obtained by calculating the salt bath furnace at 0.3~ 0.4min /mm without causing cracks. Special big, weight, thickness disparity of complex parts, such as large jaw crusher teeth plate, shape size 50 ~ 100 mm Χ Χ 1500 mm and 850 mm thickness of 50 ~ 100 mm, a single weight 900 kg, by flame furnace heating. The heat treatment process for: the < 300 ℃ charging, to 300 ℃ 2 h, reoccupy temperature 60 ℃ / h 6 h, 650 ~ 650 ℃ heat preservation 3 h, again with 100 ℃ / h up 4 h, 1050 ~ 1100 ℃ heat 6 h quenching, cracks were not found. High temperature insulation coefficient can be 1.5~1.8min/mm; Thermal insulation 2.5~3h, even using thermal insulation coefficient 1~1.2min/mm; Heat preservation for 1.67~2h can make the carbides dissolve and diffuse evenly, and obtain single austenite structure, reduce surface decarbonization and demanganization, improve wear resistance, reduce crack rejection rate and reduce energy consumption. 2) water toughening treatment process high manganese steel, high manganese steel casting wear-resisting, subject to 1050 ~ 1100 ℃ high temperature heating water toughening treatment, in order to obtain high toughness austenitic organization; Under the action of high impact load, the austenite structure on the surface of steel parts is continuously deformed and hardened, and has good wear resistance. The former high manganese steel water toughening process, the process cycle is long, the energy consumption is large. High manganese steel water toughening treatment process is: after the workpiece loading furnace with 70 ℃ / h or less heat slowly heated to 700 ℃, and then to 100 ℃ / h or less heated to a temperature of 1050 ~ 1100 ℃, 2 h are temperature, heat preservation 2 ~ 3.5 h, ensure enough soaking time, facilitate carbide dissolves. Due to the elimination of low-temperature residence and intermediate holding time, the process cycle is shortened from 16h to 14h, and the gas consumption is reduced from 11694m3/ furnace to 8256 m3/ furnace. The product quality is qualified and no cracks have occurred. 2. Energy saving heat treatment process of high manganese steel -- direct quenching with casting waste heat After casting pouring shakeout, direct quenching in 1050 ~ 1100 ℃ or high temperature type out immediately after loading furnace temperature of 1050 ~ 1100 ℃ after homogenization melt quenching. In order to obtain single austenite structure of high manganese steel (Mn13) castings, it is necessary to conduct water toughening treatment to improve the service life. Is after casting in a sand mold casting cooling before, after clear out again into the kiln heating to 1050 ~ 1100 ℃, the heat preservation for a period of time the austenite quenching in water after homogenization, austenitic organization for room temperature. However, due to the use of coal burning heating kiln, the heating speed and holding time are not accurate, often resulting in over-burning or under-burning and quenching scrap, and long processing time, consuming a lot of coal, electricity and manpower. After the high manganese steel castings pouring, in sand mold temperature is 1000 ~ 1100 ℃, also has a single austenitic organization, then such as quenching in water can also achieve the goal of water toughening treatment. Therefore, without adding any equipment, the manufacturing process of high manganese steel teeth plate was improved, and direct water was used. According to the weight and thickness of the tooth plate, the casting mold with the tooth plate is lifted to the sand cleaning department from half an hour to one hour after the tooth plate is poured. In the lifting process, the box is not opened. Casting temperature is about 1100 ℃ or so high at this time, will immediately with the tooth plate sand box into the water pool for water blasting. Because of the casting of higher temperature and mould temperature is low, so the beginning does not produce water blasting, detonation measures must be taken, the sand box hit several times in the pool wall, cause water, in the water cooling 15 ~ 20 min, when tooth plate temperature is below 200 ℃, can the tooth plate lift, such direct water quench process is completed. And then the second and third... Until it's done. In the process of water burst, tooth plate into the water depth control in 400 ~ 600 mm below the water, the water temperature is not more than 40 ℃, the water silt content less than 7% (mass fraction). 3. Fine grain treatment of high manganese steel Fine-grain heat treatment: heat the casting of 1000 ~ 1200 ℃ after solution treatment, again in 500 ~ 500 ℃ in pearlite, finally in 950 ~ 1100 ℃ and then to solid solution treatment, to achieve grain refinement, enhance toughness and wear resistance.

(1) heat treatment process of sieve plate of high chromium cast iron sinter? Sinter sieve plate is working under severe conditions of abrasive wear, consumption, import the service life of the sieve plate, about 60 days, homemade sieve plate, about 40 days, mainly due to the low domestic sieve plate hardness, eutectic carbide quantity is less, particle rough, uneven distribution, in a large number of sinter under the constant collision and friction of sieve plate tissue deformation, furrow pit, crack and hemp. Chemical composition (mass fraction) : C: 2.84%, Cr: 20.44%, Mn: 1.37%, Cu: 0.92%, Si: 0.67%,? Mn: 0.8%, S: 0.024%, P: 0.03%. The as-cast microstructure is gray-white residual austenite + martensite + white eutectic carbide distributed in large blocks or dendrites. The heat treatment can obviously refine the as-cast microstructure, improve the surface hardness, wear resistance and toughness of the casting. Heat treatment at 1000 ℃ x2h quenching + 250 ℃ x2h tempering, 60 ~ 63 HRC hardness, impact toughness of 13.14 ~ 17.30 J/c ㎡. After wear test comparison, the average import sieve plate of 4.66 mg, the original domestic sieve plate weightlessness on average 5.55 mg, 4.59 mg. The new material sieve plate weightlessness on average 4.59 mg. The service life of the new material sieve plate is more than 60 days. (2) medium manganese white cast iron lining heat treatment Typical alloy composition (mass fraction) of medium manganese white cast iron: Mn: 4.0%~5.0%, Cr: 1.5%~2.0%, Mo: 0.5%~1.0%, Cu: 1.0%~1.5%. This is because the columnar crystal size of cast iron alloy increases with the increase of manganese content. The high manganese content alloy must be tempered at high temperature after quenching, so that the precipitated secondary carbide particles have obvious focusing and coarsening during the tempering process. After the increase of manganese content, because a large amount of residual austenite after quenching occurs martensite transformation in the process of high temperature tempering, the alloy with high manganese content has greater phase change stress after high temperature tempering than low temperature tempering. Therefore, the content of manganese in white manganese cast iron should be controlled at about 0.3%. Type M23Cr2Mo low alloy white cast iron made of 950 ~ 960 ℃ x2h air cooling quenching, martensite structure. By 250 ℃ x2h to stress in low temperature tempering, 56 ~ 57 HRC hardness can be obtained, ak = 6.0 J/c ㎡. Used in a power plant ball mill lining board, surface smooth, uniform wear, no broken, wear resistance of high manganese steel lining plate of 2.32 times. (3) ZG85Cr2MnMoRE ball mill lining heat treatment Chemical composition of ZG85Cr2MnMoRE wear-resistant steel (mass fraction) : C: 0.8% ~ 0.9%, SI: 0.2% ~ 0.45%, Mn: 0.6% ~ 1.0% and Cr: 2.0% ~ 2.5%, Mo: 0.3% ~ 0.5%, RE: 0.5%, P, S acuities were 0.045% and 0.04% or less. The heat treatment process: 850 ~ 860 ℃ heating oil quenching, 500 ~ 550 ℃ tempering, quenching heat insulation coefficient calculated by 1.2 ~ 1.5 mm/min, tempering heat coefficient calculated by 2 min/mm). Liner steel has the best overall performance. 48 ~ 52 HRC 550 ℃ tempering, the hardness, impact toughness of 34.5 J/c ㎡. Organization of sorbite and austenite. (4) ZG42Cr2MnSi2MoCe ball mill lining heat treatment The liner plate of large ball mill is made of ZG42Cr2MnSi2MoCe steel. In pit type furnace is 840 ~ 860 ℃ heating, quenching oil, 280 ~ 300 ℃ tempering. C: 0.47%, Cr: 1.80%, Mn: 1.40%, Si: 1.60%, Mo: 0.3%, P 0.025%, S 0.022%, Ce proper amount. The steel after heat treatment, sigma b = 1746 mpa, ak = 22 j/c ㎡. 55.5 HRC hardness, microstructure for M + AR4.9, sulfate particles fine garden, uniform distribution. ZG42CrMnSiMoCe steel wear-resistant steel than without Ce, sigma b increased from 1648 mpa to 1746 mpa, ak value from j/c ㎡. 17 to 22 j/c ㎡., hardness increased from 53 HRC to 55 HRC. Its service life than ZGMn13 steel. (5) ZGMn13 high manganese steel liner heat treatment improvement process Lining board of large ball mill, wall thickness ranging from 22 mm to 170mm, weight around 300~600kg, severe oxidation and decarbonization of casting, long heating time, waste of energy. The improved process, shorten the heating time in half, and mechanical performance is improved, sigma b increased from 689.25 MPa to 788.9 MPa, sigma b increased from 18.0% to 29.6%, ak by 62.23 J/c ㎡. Increase to 136.71 J/c ㎡. (6) 42CrMnSiMoVB under the bainitic - martensite wear steel 42 crmnsimovb steel after 875 ℃ is fire, 450 ℃ tempering hardness can be obtained 50.6 HRC, A = 17.0 J impact work, sigma b = 1725 MPa, the delta 5 = 9%, ￠= 25.2% bedplate of hydraulic press and skateboard original using 5 crmnmo steel, wear resistance is poor, only use 3 weeks; The service life of 42CrMnSiMoVB steel is increased more than 3 times.