General statements can be made and are worthy of consideration when selecting grinding media. For the best results it has been found that the smallest diameter ball or rod which will break down the particular material to be ground is desirable since greatest surface area is obtained. From the standpoint of economy, the larger the media the higher will be the liner consumption and media consumption. The minimum size of grinding balls should be selected with caution since there will be a tendency for such balls to float out of the mill in a dense pulp (this is minimised by the use of a grate discharge mill). Also the smaller the media the quicker it will reach its reject size.
For the first stage of grinding, media will generally be in the 4 to 2 size (in some cases as high as 5). In secondary finer grinding the initial charge will begin at around 3 and in the case of balls will grade down to about . Extremely fine grinding will dictate the use of 1 and smaller balls.
Grinding media is the working part of a mill. It will consume power whether it is doing grinding work or not. The amount of work which it does depends upon its size, its material, its construction and the quantity involved. It is, therefore, advantageous to select the type of grinding media which will prove most economical, the size of media which will give the best grinding results, and the quantity of media which will just produce the grind required.
One of the economic factors of grinding is the wear of the grinding media. This is dependent upon the material used in its manufacture, method of manufacture, size of media, diameter of mill, speed of mill, pulp level maintained in the mill, rate of feed, density of pulp maintained, shape of the liner surface, nature of the feed, and the problem of corrosion.
Many shapes of grinding media have been tried over the past years, but essentially there are only two efficient types of media used. These are the spherical ball and the cylindrical rod. Other shapes are relatively expensive to manufacture and they have shown no appreciable improvement in grinding characteristics.
It will be found that a seasoned charge will provide a better grind than a new mill charge. This, of course, is impossible to determine at the offset, but after continuous operation the media charge should be checked for size and weight, and maintained at that optimum point. After the charge has been selected, replacement media should be made at the maximum size used. In some cases it has been found advantageous to add replacement media of two or more sizes, so as to maintain more closely the seasoned ratio.
As a general figure rod mills will have a void space within the charge of around 20% to 22% for new rods. In ball mills the theoretical void space is around 42% to 43%. It has been found that as grinding rods wear a 4 or 4 rod will generally break up at about 1 diameter. The smaller diameter new rods do not break up as easily and will generally wear down to about 1. In many applications it has been found, that grinding efficiency will increase if rods are removed when they reach the 1 size, and also if broken pieces of rods are removed. The Open End Rod Mill has the advantage of allowing the quick and easy removal of such rods.
It is difficult to give figures on media consumption since there are so many variables. Rods will be consumed at the rate of 0.2# per ton on soft easily ground material up to 2# per ton on harder material. Steel consumption of balls is spread out over an even greater range. Some indication as to media consumption can be obtained from power consumed in grinding. For example, balls or rods will generally wear at a rate of about 1# for each 6 or 7 kilowatt hours consumed per ton of ore. Liner consumption is generally about one-fifth of the media consumption.
We areprepared to furnish alltypes and sizes of steel rods as shown in table. Standard sizes of these rods are finest quality, high carbon, hot rolled, machine straightened steel and meet low cost, long wear requirements for use in operation of all types of rod mills.
Steel Grinding Rods are made of a special steel which breaks up without twisting when final wear occurs. This is extremely important in maintaining full grinding capacity and eliminating the difficulty of removing wire-like, worn rods which twist and bend into an inseparable and space filling mass of interlaced wires if breaking does not occur. Rods are shipped in lengths cut to suit the length of each particular customers rod mill.
Rods are to be hot rolled, hot sawed or sheared, with standard tolerance and machine straightened. We have found that a good grade of forged steel grinding balls is generally most efficient for use with our grate discharge ball mills.
Steel balls ranging from to 5 in. in diameter are used. Rods range from 1 to 4 in. in diameter and should be 3 to 4 in. shorter than the inside mill length. Tube mills are usually fed balls smaller than 2 in., whereas 4- or 5-in. balls are more commonly used for ball-mill grinding. A much higher grinding capacity is obtained in tube mills by using steel media instead of pebbles, but in making such a conversion serious consideration must be given to the ability of the steel shell to withstand the greater loading.
Approximate ball loads can be estimated by assuming 300 lb. per cu. ft. of ball volume and a total load equivalent to 40 to 45 per cent of the mill volume. Rod loads average about 40 per cent of mill volume, and a figure of 400 to 425 lb. per cu. ft. of rod volume should be taken.
Experience indicates that rods are superior to balls for feeds in the range from to 1 in. maximum when the mill is not called upon to finish at sizes finer than 14 mesh. Balls are superior at coarser feed sizes or for finishing 1-in. feeds to 28 mesh of grind or finer because the mill can be run cataracting and the large lumps broken by hammering.
In an operating mill a seasoned charge, containing media of all sizes from that of the renewal or replacement size down to that which discharges automatic ally, normally produces better grinding than a new charge. It is inferred from this that a charge should be rationed to the mill feed, i.e., that it should contain media of sizes best suited to each of the particle sizes to be ground. Usual practice is, however, to charge a new mill with a range of sizes, based on an assumed seasoned load; thereupon to make periodic renewals, at various sizes dependent upon the character of the circulating load, until optimum grinding is obtained; and thereafter to make required renewals at the optimum size.
A coarse feed requires larger (grinding) media than a finer feed. The smaller the mesh of grind the smaller the optimum diameter of the medium. This relationship is attributed to the fact that fine product is produced most effectively by rubbing, whence maximum capacity to fine sizes is attained by maximum rubbing surface, i.e., with small balls. A practical limitation is imposed by the tendency for balls that are too small to float* out of the mill and by the high percentage of rejects when renewals are too small.
The usual materials for balls are chilled cast iron and forged steel, for rods, high- carbon steel, (0.8 to 1.0 per cent carbon) all more or less alloyed. Mild steel rods are unsuitable for the reason that they bend and kink after wearing down to a certain minimum diameter and snarl up the whole rod load. The hardened steel rods break up when they wear down and are removed at about 1 in. or left in an eventually discharge in small pieces.
If you know the price of a 3 grinding ball or what the cost of a 75mm piece of grinding ballis, you can estimate, in a relative way, the price of larger and smaller grinding media. It will serve you well when creating an operating budget.
These balls are cast alloy steel, and are made by the newly developed Payne Hot Top principle. This principle employs a rotating casting machine. This machine rotates and the molds move under the pouring spout and hot metal runs down a trough on top of the molds. Four or five molds are either filling or cooling under this stream of hot steel. By this means the heads are kept liquid, eliminating the need for risers and allowing all of the gasses to escape. For this reason the balls are solid, free from gas cavities, and show wear resistance equal to the best forged steel balls. These balls may be had in two types: a soft ball Brinnell 450+ for large diameter ball mills, and a hard ball Brinnell 600+ for small ball mills. The addition of molybdenum, chromium and manganese provides an excellent microstructure for these grinding balls. Balls are available in 4, 3, 3, 2, and 2 sizes.
As the developer and manufacturer of industry-leading particle size reduction equipment, including Attritors (internally agitated ball mills) and DMQX horizontal media mills, Union Process is uniquely positioned to help you identify and source the correct grinding media for your application.
Union Process customers know they can rely on our extensive technical expertise and years of experience to ensure they get the right grinding media at the right time and the right price for their specific needs. Working in close consultation with our customers, our skilled technical service representatives reviewcustomer requirements like final particle size, physical compatibility and contamination concernsand then recommend media with the right characteristics, including:
metallic grinding medialike carbon steel, forged steel, stainless steel or chrome steel grinding balls are best for some applications, while others requirenon-metallic mediamade of alumina, ceramics, glass, silicon carbide, zirconium oxide or other specialized materials
Union Process is the source for the most up-to-date information on grinding balls and other media. Download our Grinding Media Literature (PDF) to view a detailed sheet, outlining factors to consider when selecting grinding media, along with specifications on the most common types of media.
Offering the optimal combination of grinding media knowledge and manufacturing expertise, Union Process takes your entire operation into account to identify the best grinding media to consistently generate the final particle size and shape required by your application, optimizing the cost effectiveness of your process and extending the life of your mills.
Backed by our long-standing commitment to customer satisfaction, we ensure quality manufacturing and reliable supply of grinding balls and media specifically engineered to meet the requirements of your most demanding milling applications.
Through-Hardened Carbon Steel Balls are magnetic and can be used in the food industry along with 440C stainless steel media. They are a low-cost media that are superior and recommended over case-hardened carbon steel media which have a soft core. They are packaged with no oil finishalways dry packedas they will rust in water.
Chrome Balls (steel type 52100) are through-hardened and tempered steel balls designed to achieve maximum strength and quality. Ball hardness is in the 6067 HRC range. They wear better than 440C stainless steel and through-hardened carbon steel. They are also recommended for applications where a through-hardened steel ball is needed in larger sizes ( and larger). They are sometimes packaged with a very light oil finish to reduce rust due to humidity.
440C Stainless Steel Balls are through-hardened and tempered throughout for maximum strength and quality. They are magnetic, and corrosion-resistant (generally rust-resistant). They are recommended for food applications and lighter colored slurries.
Forged Steel Balls are used for gold mining, cement factories, oil processing and large scale industrial applications. They are made by machine (standard) sizes 20mm75mm. They are manually made (hit by air hammer) sizes 75mm125mm. They have hardness 5563 HRC. All forged balls are through-hardened, and shipped in 55-gallon steel drums. They range in sizes from 20mm125mm. Standard lead time is 68 weeks FOB Akron, Ohio USA.
High Chrome Steel Balls can be used for many different applications. They are available in two grades1013% chrome (surface hardness 60 HRC, core hardness 58 HRC), and 1418% chrome (surface hardness 62 HRC, core hardness 60 HRC). They have a very rough black finish which quickly wears off during initial milling. After that, they have an excellent wear rate. They are available in sizes 6mm120mm. They are shipped in 55-gallon steel drums with standard lead time of 68 weeks FOB Akron, Ohio USA.
Union Process is the one source for 90%, 94%, 99.5% and 99.9% alumina media. 90% alumina is available in satellites and rod/cylinders. 94% alumina balls have excellent wear resistance with higher impact strength to save running costs with less contamination. They have great wear rate generally better than 90% or 99.5%. 99.5% alumina balls have the highest alumina content for a moderate price. The .5% impurity is MgO that is added to inhibit grain growth during sintering in the kiln. There is less than 0.1% silica in the media. 99.9% alumina balls are made of very pure and reactive (expensive) raw materials. They are for high purity alumina applications where contamination is a factor.
Alumina Beads are specially formulated to be used in high-energy mills in which a high degree of fineness is required. They are used in various industrial fields such as inks, paints, advanced ceramics, mining, cosmetics and pharmaceutical industries. They are a perfectly spherical shape with high mechanical properties and high wear resistance at a moderate price.
Silicon Carbide Balls are very high-cost grinding media that are used for milling same materials (silicon carbide ball to mill silicon carbide materials) to avoid contamination. They are only available in 5mm,10mm, 15mm and 20mm sizes. They are a special order item.
Silicon Nitride Balls are very high-cost grinding media that are used for milling same materials (silicon nitride ball to mill silicon nitride materials) to avoid contamination. They are now available in 2mm and 3mm and sizes up to 25mm. They are a special order item.
Tungsten Carbide media is the hardest and densest (highest specific gravity) media and is available in both satellites and balls upon request. They are available in sizes ranging from 3/32 to 1 in diameter. They are a high-cost media and are a special order item.
Zirconium Oxide Balls (95% ZrO2) are the strongest, best wearing ceramic media for metal-free, pharmaceutical and food processing grinding. These balls have a white, shiny appearance. They are also available in 38 and cylinders. This 95% grade is high-cost.
Zirconium Oxide SatellitesCeria stabilized (rare earth)are a cheaper zirconium oxide alternative for metal-free applications. They are a brown, shiny ball media that come in size ranges in the smallest sizes (ex: 0.4 0.6mm), then at 6mm come in uniform sizes (6mm, 8mm, etc.) up to 31mm.
Zirconium Silicate Beads are available in fused 68% ZrO2 beads which are a standard reliable media at low cost, and sintered 58% ZrO2 beads which have high breakage resistance, are durable and cost effective. They are used to microgrind paints, inks, dyes, magnetic coatings, minerals, agrochemicals and ceramics.
NOTE: Grinding balls and media are sold on a per pound basis, but ATTRITORS and DMQX-Mills are loaded by volume. Therefore, the more dense the media, the more pounds of media required. For instance, a machine requiring only 40 lbs. of stainless steel may require up to 80 lbs. of tungsten carbide. Information contained herein is accurate and reliable to the best of our knowledge, but our suggestions and recommendations cannot be guaranteed because the conditions of use are beyond our control.
Our skilled technical service representatives also are available for consultation and are always ready to assist you with the selection of grinding media that best answer your particular needs. For assistance, contact Media Sales by calling (330) 929-3333 x228 or byemailing us.
Grinding steelBallsAppliedFields 1.Mining 2.CementPlants 3.ChemicalIndustries 4.PowerStations Advantages of Jinan Zhongwei Grinding Balls 1.Electric Furnace as compared to coal 2.Fair Market Price 3.Quality guarantee 4.On time delivery Our Services We supply forged steel grinding steel balls with diamater 20mm-150mm. We supply casted iron grinding steelballs with diamater 20mm-150mm. We supply grinding rods made by C45 Steel ,60Mn Steel,B2 Steel,B3 Steel. We supply grinding cylpeb (Cylinder) with High Chrome,Low Chrome,Medium Chrome PhysicalPropertyofForged grinding steelBallsGrindingMedia Model Material ImpactTest Ak.J/cm SurfaceHardness (25mm-60mm) CoreHardness (25mm-60mm) SurfaceHardness (70mm-100mm) CoreHardness (70mm-100mm) ZW-1 50Mn 12 56 35 56 28 ZW-2 60Mn 13 58 38 58 29 ZW-3 65Mn 15 60 42 60 30 ZW-4 B2 17 60 52 60 50 ZW-5 75SiMn 16 60 50 60 48 PhysicalProperty ofCast grinding steel BallsGrindingMedia Model BRAND HARDNESS IMPACT VALUE ak(J/cm2) METALLOGRAPHIC ORGANIZATION QUENCHINGSTATE(A) NO-QUENCHINGSTATE(A) HighChromium CastingBall ZQCr26 60 45 4.0 M+C Packaging&Shipping Packing:Containerbagsorsteeldrumsorothers. ForContainerBag,Netweight1000Kgs,GrossWeight1002KGS,Measurement0.4CBM ForSteelDrums,Netweight850-950Kgs,GrossWeight865-965KGS,Measurement0.3CBM. Shippinganddelivery Portofloading:QingdaoPort,China Deliverytime:Normally2-3weeksafterdownpaymentreceived. Partialshippmentallowed FAQ Paymentterms:T/T(30%DP,balanceagainstcopyofB/L.;L/C Samples:Freesamplesareprovidedfortestbeforetrialorder MOQ:1Ton BriefIntroductionof our company: JinanZhongweiisaleadingproducerofhighchromeandforgedGrindingSteelBalls suppliedtotheplatinum,copperandgoldminingindustries. We are ISO endorsed company ,located in Zhangqiu,china. Weareabletoproducecasthighchromeandforgedgrindingmediainarangeofsizes, meaningweareabletosupplycustomerswithvaryingoreandmilltypes. Formoreinformationaboutourproducts,Plsfeelfreetocontactus.
Established in 2000, We Jinan Zhongwei casting and forging grinding ball Co.,Ltd, are leading manufacturer and professional exporter of grinding media balls in China. with the annual output of 50,000 ...
JINAN ZHONGWEI CASTING AND FORGING GRINDING BALL CO.,LTD 18 Years Focus on Development and Production of Grinding Media 2000 Established Jinan Zhongwei Casting And Forging Grinding Ball Co.,Ltd 2004 Adding 20-25mm hot rolling Auto production line. 2008 Our products are widely...
Professional: Just tell us your requirements, our engineers can suggest the suitable material for you. Easy: As our clients, all you have to do is choose, not answer a lot of boring questions. Prompt: You can get a reply within one hour in working day, within 5 hours in holidays. About delivery d...
Jinan Zhongwei Casting & Forging is made up of a highly qualified professional team, with professional top talent and technology together. We have R & D Dep., QC Dep., Production Dep., Sales Dep., and After-sales service Dep., as the expansion of our business, we must will do our best to meet your needs, and welcom more friends come t...