china mining equipments manufacturer, minerals processing equipments, crushing machine supplier - gongyi hengchang metallurgical building material equipments plant
Mining Equipments, Crushing Machine, Drying Machine manufacturer / supplier in China, offering PE/Pex Series 200 Tph Stone Jaw Crusher Machine, Multi-Layer Carbon Steel Aggregate River Stone Screen, Small Mini Jaw Crusher PE150*250 and so on.
Gongyi Hengchang Metallurgical Building Material Equipments plant is a professional manufacturer of complete set mineral beneficiation equipments, Briquette equipments, coal preparation equipments, ball press equipments, products widely used in mineral processing, metallurgy, building materials, chemicals, electricity, petroleum, coal, transportation, fertilizer, gas industry etc. In the last two decades, we always persist on the philosophy of "scientific and technological innovation, quality first, ...
In all ore dressing and milling Operations, including flotation, cyanidation, gravity concentration, and amalgamation, the Working Principle is to crush and grind, often with rob mill & ball mills, the ore in order to liberate the minerals. In the chemical and process industries, grinding is an important step in preparing raw materials for subsequent treatment.In present day practice, ore is reduced to a size many times finer than can be obtained with crushers. Over a period of many years various fine grinding machines have been developed and used, but the ball mill has become standard due to its simplicity and low operating cost.
A ball millefficiently operated performs a wide variety of services. In small milling plants, where simplicity is most essential, it is not economical to use more than single stage crushing, because the Steel-Head Ball or Rod Mill will take up to 2 feed and grind it to the desired fineness. In larger plants where several stages of coarse and fine crushing are used, it is customary to crush from 1/2 to as fine as 8 mesh.
Many grinding circuits necessitate regrinding of concentrates or middling products to extremely fine sizes to liberate the closely associated minerals from each other. In these cases, the feed to the ball mill may be from 10 to 100 mesh or even finer.
Where the finished product does not have to be uniform, a ball mill may be operated in open circuit, but where the finished product must be uniform it is essential that the grinding mill be used in closed circuit with a screen, if a coarse product is desired, and with a classifier if a fine product is required. In most cases it is desirable to operate the grinding mill in closed circuit with a screen or classifier as higher efficiency and capacity are obtained. Often a mill using steel rods as the grinding medium is recommended, where the product must have the minimum amount of fines (rods give a more nearly uniform product).
Often a problem requires some study to determine the economic fineness to which a product can or should be ground. In this case the 911Equipment Company offers its complete testing service so that accurate grinding mill size may be determined.
Until recently many operators have believed that one particular type of grinding mill had greater efficiency and resulting capacity than some other type. However, it is now commonly agreed and accepted that the work done by any ballmill depends directly upon the power input; the maximum power input into any ball or rod mill depends upon weight of grinding charge, mill speed, and liner design.
The apparent difference in capacities between grinding mills (listed as being the same size) is due to the fact that there is no uniform method of designating the size of a mill, for example: a 5 x 5 Ball Mill has a working diameter of 5 inside the liners and has 20 per cent more capacity than all other ball mills designated as 5 x 5 where the shell is 5 inside diameter and the working diameter is only 48 with the liners in place.
Ball-Rod Mills, based on 4 liners and capacity varying as 2.6 power of mill diameter, on the 5 size give 20 per cent increased capacity; on the 4 size, 25 per cent; and on the 3 size, 28 per cent. This fact should be carefully kept in mind when determining the capacity of a Steel- Head Ball-Rod Mill, as this unit can carry a greater ball or rod charge and has potentially higher capacity in a given size when the full ball or rod charge is carried.
A mill shorter in length may be used if the grinding problem indicates a definite power input. This allows the alternative of greater capacity at a later date or a considerable saving in first cost with a shorter mill, if reserve capacity is not desired.
The capacities of Ball-Rod Mills are considerably higher than many other types because the diameters are measured inside the liners.
The correct grinding mill depends so much upon the particular ore being treated and the product desired, that a mill must have maximum flexibility in length, type of grinding medium, type of discharge, and speed.With the Ball-Rod Mill it is possible to build this unit in exact accordance with your requirements, as illustrated.
To best serve your needs, the Trunnion can be furnished with small (standard), medium, or large diameter opening for each type of discharge. The sketch shows diagrammatic arrangements of the four different types of discharge for each size of trunnion opening, and peripheral discharge is described later.
Ball-Rod Mills of the grate discharge type are made by adding the improved type of grates to a standard Ball-Rod Mill. These grates are bolted to the discharge head in much the same manner as the standard headliners.
The grates are of alloy steel and are cast integral with the lifter bars which are essential to the efficient operation of this type of ball or rod mill. These lifter bars have a similar action to a pump:i. e., in lifting the product so as to discharge quickly through the mill trunnion.
These Discharge Grates also incorporate as an integral part, a liner between the lifters and steel head of the ball mill to prevent wear of the mill head. By combining these parts into a single casting, repairs and maintenance are greatly simplified. The center of the grate discharge end of this mill is open to permit adding of balls or for adding water to the mill through the discharge end.
Instead of being constructed of bars cast into a frame, Grates are cast entire and have cored holes which widen toward the outside of the mill similar to the taper in grizzly bars. The grate type discharge is illustrated.
The peripheral discharge type of Ball-Rod Mill is a modification of the grate type, and is recommended where a free gravity discharge is desired. It is particularly applicable when production of too many fine particles is detrimental and a quick pass through the mill is desired, and for dry grinding.
The drawings show the arrangement of the peripheral discharge. The discharge consists of openings in the shell into which bushings with holes of the desired size are inserted. On the outside of the mill, flanges are used to attach a stationary discharge hopper to prevent pulp splash or too much dust.
The mill may be operated either as a peripheral discharge or a combination or peripheral and trunnion discharge unit, depending on the desired operating conditions. If at any time the peripheral discharge is undesirable, plugs inserted into the bushings will convert the mill to a trunnion discharge type mill.
Unless otherwise specified, a hard iron liner is furnished. This liner is made of the best grade white iron and is most serviceable for the smaller size mills where large balls are not used. Hard iron liners have a much lower first cost.
Electric steel, although more expensive than hard iron, has advantage of minimum breakage and allows final wear to thinner section. Steel liners are recommended when the mills are for export or where the source of liner replacement is at a considerable distance.
Molychrome steel has longer wearing qualities and greater strength than hard iron. Breakage is not so apt to occur during shipment, and any size ball can be charged into a mill equipped with molychrome liners.
Manganese liners for Ball-Rod Mills are the world famous AMSCO Brand, and are the best obtainable. The first cost is the highest, but in most cases the cost per ton of ore ground is the lowest. These liners contain 12 to 14% manganese.
The feed and discharge trunnions are provided with cast iron or white iron throat liners. As these parts are not subjected to impact and must only withstand abrasion, alloys are not commonly used but can be supplied.
Gears for Ball-Rod Mills drives are furnished as standard on the discharge end of the mill where they are out of the way of the classifier return, scoop feeder, or original feed. Due to convertible type construction the mills can be furnished with gears on the feed end. Gear drives are available in two alternative combinations, which are:
All pinions are properly bored, key-seated, and pressed onto the steel countershaft, which is oversize and properly keyseated for the pinion and drive pulleys or sheaves. The countershaft operates on high grade, heavy duty, nickel babbitt bearings.
Any type of drive can be furnished for Ball-Rod Mills in accordance with your requirements. Belt drives are available with pulleys either plain or equipped with friction clutch. Various V- Rope combinations can also be supplied.
The most economical drive to use up to 50 H. P., is a high starting torque motor connected to the pinion shaft by means of a flat or V-Rope drive. For larger size motors the wound rotor (slip ring) is recommended due to its low current requirement in starting up the ball mill.
Should you be operating your own power plant or have D. C. current, please specify so that there will be no confusion as to motor characteristics. If switches are to be supplied, exact voltage to be used should be given.
Even though many ores require fine grinding for maximum recovery, most ores liberate a large percentage of the minerals during the first pass through the grinding unit. Thus, if the free minerals can be immediately removed from the ball mill classifier circuit, there is little chance for overgrinding.
This is actually what has happened wherever Mineral Jigs or Unit Flotation Cells have been installed in the ball mill classifier circuit. With the installation of one or both of these machines between the ball mill and classifier, as high as 70 per cent of the free gold and sulphide minerals can be immediately removed, thus reducing grinding costs and improving over-all recovery.
The advantage of this method lies in the fact that heavy and usually valuable minerals, which otherwise would be ground finer because of their faster settling in the classifier and consequent return to the grinding mill, are removed from the circuit as soon as freed. This applies particularly to gold and lead ores.
Ball-Rod Mills have heavy rolled steel plate shells which are arc welded inside and outside to the steel heads or to rolled steel flanges, depending upon the type of mill. The double welding not only gives increased structural strength, but eliminates any possibility of leakage.
Where a single or double flanged shell is used, the faces are accurately machined and drilled to template to insure perfect fit and alignment with the holes in the head. These flanges are machined with male and female joints which take the shearing stresses off the bolts.
The Ball-Rod Mill Heads are oversize in section, heavily ribbed and are cast from electric furnace steel which has a strength of approximately four times that of cast iron. The head and trunnion bearings are designed to support a mill with length double its diameter. This extra strength, besides eliminating the possibility of head breakage or other structural failure (either while in transit or while in service), imparts to Ball-Rod Mills a flexibility heretofore lacking in grinding mills. Also, for instance, if you have a 5 x 5 mill, you can add another 5 shell length and thus get double the original capacity; or any length required up to a maximum of 12 total length.
On Type A mills the steel heads are double welded to the rolled steel shell. On type B and other flanged type mills the heads are machined with male and female joints to match the shell flanges, thus taking the shearing stresses from the heavy machine bolts which connect the shell flanges to the heads.
The manhole cover is protected from wear by heavy liners. An extended lip is provided for loosening the door with a crow-bar, and lifting handles are also provided. The manhole door is furnished with suitable gaskets to prevent leakage.
The mill trunnions are carried on heavy babbitt bearings which provide ample surface to insure low bearing pressure. If at any time the normal length is doubled to obtain increased capacity, these large trunnion bearings will easily support the additional load.
Trunnion bearings are of the rigid type, as the perfect alignment of the trunnion surface on Ball-Rod Mills eliminates any need for the more expensive self-aligning type of bearing.
The cap on the upper half of the trunnion bearing is provided with a shroud which extends over the drip flange of the trunnion and effectively prevents the entrance of dirt or grit. The bearing has a large space for wool waste and lubricant and this is easily accessible through a large opening which is covered to prevent dirt from getting into the bearing.Ball and socket bearings can be furnished.
Scoop Feeders for Ball-Rod Mills are made in various radius sizes. Standard scoops are made of cast iron and for the 3 size a 13 or 19 feeder is supplied, for the 4 size a 30 or 36, for the 5 a 36 or 42, and for the 6 a 42 or 48 feeder. Welded steel scoop feeders can, however, be supplied in any radius.
The correct size of feeder depends upon the size of the classifier, and the smallest feeder should be used which will permit gravity flow for closed circuit grinding between classifier and the ball or rod mill. All feeders are built with a removable wearing lip which can be easily replaced and are designed to give minimum scoop wear.
A combination drum and scoop feeder can be supplied if necessary. This feeder is made of heavy steel plate and strongly welded. These drum-scoop feeders are available in the same sizes as the cast iron feeders but can be built in any radius. Scoop liners can be furnished.
The trunnions on Ball-Rod Mills are flanged and carefully machined so that scoops are held in place by large machine bolts and not cap screws or stud bolts. The feed trunnion flange is machined with a shoulder for insuring a proper fit for the feed scoop, and the weight of the scoop is carried on this shoulder so that all strain is removed from the bolts which hold the scoop.
High carbon steel rods are recommended, hot rolled, hot sawed or sheared, to a length of 2 less than actual length of mill taken inside the liners.
The initial rod charge is generally a mixture ranging from 1.5 to 3 in diameter. During operation, rod make-up is generally the maximum size. The weights per lineal foot of rods of various diameters are approximately: 1.5 to 6 lbs.; 2-10.7 lbs.; 2.5-16.7 lbs.; and 3-24 lbs.
Forged from the best high carbon manganese steel, they are of the finest quality which can be produced and give long, satisfactory service.
Data on ball charges for Ball-Rod Mills are listed in Table 5. Further information regarding grinding balls is included in Table 6.
Rod Mills has a very define and narrow discharge product size range. Feeding a Rod Mill finer rocks will greatly impact its tonnage while not significantly affect its discharge product sizes. The 3.5 diameter rod of a mill, can only grind so fine.
Crushers are well understood by most. Rod and Ball Mills not so much however as their size reduction actions are hidden in the tube (mill). As for Rod Mills, the image above best expresses what is going on inside. As rocks is feed into the mill, they are crushed (pinched) by the weight of its 3.5 x 16 rods at one end while the smaller particles migrate towards the discharge end and get slightly abraded (as in a Ball Mill) on the way there.
We haveSmall Ball Mills for sale coming in at very good prices. These ball mills are relatively small, bearing mounted on a steel frame. All ball mills are sold with motor, gears, steel liners and optional grinding media charge/load.
Ball Mills or Rod Mills in a complete range of sizes up to 10 diameter x20 long, offer features of operation and convertibility to meet your exactneeds. They may be used for pulverizing and either wet or dry grindingsystems. Mills are available in both light-duty and heavy-duty constructionto meet your specific requirements.
All Mills feature electric cast steel heads and heavy rolled steelplate shells. Self-aligning main trunnion bearings on large mills are sealedand internally flood-lubricated. Replaceable mill trunnions. Pinion shaftbearings are self-aligning, roller bearing type, enclosed in dust-tightcarrier. Adjustable, single-unit soleplate under trunnion and drive pinionsfor perfect, permanent gear alignment.
Ball Mills can be supplied with either ceramic or rubber linings for wet or dry grinding, for continuous or batch type operation, in sizes from 15 x 21 to 8 x 12. High density ceramic linings of uniform hardness male possible thinner linings and greater and more effective grinding volume. Mills are shipped with liners installed.
Complete laboratory testing service, mill and air classifier engineering and proven equipment make possible a single source for your complete dry-grinding mill installation. Units available with air swept design and centrifugal classifiers or with elevators and mechanical type air classifiers. All sizes and capacities of units. Laboratory-size air classifier also available.
A special purpose batch mill designed especially for grinding and mixing involving acids and corrosive materials. No corners mean easy cleaning and choice of rubber or ceramic linings make it corrosion resistant. Shape of mill and ball segregation gives preferential grinding action for grinding and mixing of pigments and catalysts. Made in 2, 3 and 4 diameter grinding drums.
Nowadays grinding mills are almost extensively used for comminution of materials ranging from 5 mm to 40 mm (3/161 5/8) down to varying product sizes. They have vast applications within different branches of industry such as for example the ore dressing, cement, lime, porcelain and chemical industries and can be designed for continuous as well as batch grinding.
Ball mills can be used for coarse grinding as described for the rod mill. They will, however, in that application produce more fines and tramp oversize and will in any case necessitate installation of effective classification.If finer grinding is wanted two or three stage grinding is advisable as for instant primary rod mill with 75100 mm (34) rods, secondary ball mill with 2540 mm(11) balls and possibly tertiary ball mill with 20 mm () balls or cylpebs.To obtain a close size distribution in the fine range the specific surface of the grinding media should be as high as possible. Thus as small balls as possible should be used in each stage.
The principal field of rod mill usage is the preparation of products in the 5 mm0.4 mm (4 mesh to 35 mesh) range. It may sometimes be recommended also for finer grinding. Within these limits a rod mill is usually superior to and more efficient than a ball mill. The basic principle for rod grinding is reduction by line contact between rods extending the full length of the mill, resulting in selective grinding carried out on the largest particle sizes. This results in a minimum production of extreme fines or slimes and more effective grinding work as compared with a ball mill. One stage rod mill grinding is therefore suitable for preparation of feed to gravimetric ore dressing methods, certain flotation processes with slime problems and magnetic cobbing. Rod mills are frequently used as primary mills to produce suitable feed to the second grinding stage. Rod mills have usually a length/diameter ratio of at least 1.4.
Tube mills are in principle to be considered as ball mills, the basic difference being that the length/diameter ratio is greater (35). They are commonly used for surface cleaning or scrubbing action and fine grinding in open circuit.
In some cases it is suitable to use screened fractions of the material as grinding media. Such mills are usually called pebble mills, but the working principle is the same as for ball mills. As the power input is approximately directly proportional to the volume weight of the grinding media, the power input for pebble mills is correspondingly smaller than for a ball mill.
A dry process requires usually dry grinding. If the feed is wet and sticky, it is often necessary to lower the moisture content below 1 %. Grinding in front of wet processes can be done wet or dry. In dry grinding the energy consumption is higher, but the wear of linings and charge is less than for wet grinding, especially when treating highly abrasive and corrosive material. When comparing the economy of wet and dry grinding, the different costs for the entire process must be considered.
An increase in the mill speed will give a directly proportional increase in mill power but there seems to be a square proportional increase in the wear. Rod mills generally operate within the range of 6075 % of critical speed in order to avoid excessive wear and tangled rods. Ball and pebble mills are usually operated at 7085 % of critical speed. For dry grinding the speed is usually somewhat lower.
The mill lining can be made of rubber or different types of steel (manganese or Ni-hard) with liner types according to the customers requirements. For special applications we can also supply porcelain, basalt and other linings.
The mill power is approximately directly proportional to the charge volume within the normal range. When calculating a mill 40 % charge volume is generally used. In pebble and ball mills quite often charge volumes close to 50 % are used. In a pebble mill the pebble consumption ranges from 315 % and the charge has to be controlled automatically to maintain uniform power consumption.
In all cases the net energy consumption per ton (kWh/ton) must be known either from previous
experience or laboratory tests before mill size can be determined. The required mill net power P kW ( = ton/hX kWh/ton) is obtained from
Trunnions of S.G. iron or steel castings with machined flange and bearing seat incl. device for dismantling the bearings. For smaller mills the heads and trunnions are sometimes made in grey cast iron.
The mills can be used either for dry or wet, rod or ball grinding. By using a separate attachment the discharge end can be changed so that the mills can be used for peripheral instead of overflow discharge.
china ball mill equipment manufacturer, rotary dryer, sand making machine supplier - zhengzhou hengxing heavy equipment co., ltd
Ball Mill Equipment, Rotary Dryer, Sand Making Machine manufacturer / supplier in China, offering Energy Saving Briquette Mesh Belt Dryer, Mini Sand Making Machine for Cobble Stone, Good Quality Dewatering Screen for Tailings with Polyurethane Screen and so on.
Zhengzhou Hengxing Heavy Equipment Co., Ltd. is a joint stock corporation integrating research and manufacture sale with the targt at the large and medium sized series of heavy equipment for mine machinery, wall materies, formed coal, metallurgy and etc. The company is located at No. 8 Hongye Road, West Hehuan Street, High-Tech Development Zone, Zhengzhou, China. Since establishment, our company has gathered a group of scientific elites with modernized management system and accurate production as well ...
equipment to recover gold without chemicals
The i350is a family member of the Falcon Gravity Concentrators Gold Mining Equipment which has revolutionizing the world of alluvial gold mining and dredging the same way its little brother, the i150, has impacted the world of hard rock mining.This is a gravimetric mineral concentrator that uses enhanced gravity (Gs) to concentrate the free heavy minerals. It is also known as a centrifugal concentrator because of the centrifugal action of the spinning bowl.
Due to the ability to capture fine gold and the high concentration ratios, the i350 Gravity Concentrator can be used to minimize the length of your sluice and minimize the amount of concentrate in your operation.
iCON is a family of mineral processing products specifically designed to recover fine precious metals including Gold, Silver and Platinum. The product line includes concentrators, slurry pumps, vibrating screens and modular plants.
iCON was designed by the professional mineral processing engineers of Falcon concentrators. iCON has all the quality, reliability and performance you would expect from Canadian designed and patented equipment.
Hard Rock miners around the world have historically recovered as little as 30% of their free gold using mercury amalgamation. The iCON process is being used to scavenge/reprocess old tails without using mercury. These miners are now recovering more gold reprocessing tails with iCON than the original miners recovered. They are also recovering significant quantities of Mercury.
The number 1 application for iCON i350 worldwide is Hard Rock. The 10-15 TPH capacity and the ability to recover fine, flat milled gold are ideal for iCON. The major mines of the world use gravity concentration in their grinding circuits. The concentrators can recover over 90% of the overall production of major/professional mines.
A typical Hard Rock application would involve a crusher and ball mill. The material would be size classified using a cyclone in closed-circuit or simply a screen in semi-closed circuit milling. After the mill the material will pass through the concentrator. The major mines have a recyclic load. Their processes are designed for the feed to pass through a concentrator multiple times before passing to the tails.
A Hard Rock operator may choose to run 15 tons per hour of a high grade ore. He may choose to rinse the bowl every 20 minutes. Here, he would have run 5 tons in 20 minutes and collected 10 kg of concentrate. That is a concentration ratio of 500 to 1.
The concentrate will still need to be upgraded or cleaned to have a sellable product. Some miners around the world are choosing to collect the concentrates from multiple mine sites and clean the cons at a regional secure facility. This is known as pre-concentration.
When scavenging old tails the operator must understand that there is a reason the first miner missed this gold. It may be that it was poorly milled and needs to be re-milled to liberate more gold. In order to recover what another team missed the operator must pay attention to the details and be prepared to adjust their process as required. To understand your ore and how much gold you can expect to recover, IGR recommends testing your samples at lab.
Alluvial miners often ignore the fine gold because sluices and jigs cant catch it. Depending on the size and shape of your gold a sluice may begin to lose gold at 40 mesh. Some alluvial deposits have 90% of their gold finer than this. This is where enhanced gravity, iCON, is the only solution.
Concentrators are being tested on the ends of sluices and dredges. In this case the operation is still capturing the same amount of gold in the sluice. The added value of the concentrator becomes very clear.
After seeing the additional recovery of the concentrator some operators are choosing to redesign their process. An efficient plant design would include a screen (typically 2mm or 10 mesh) where only the coarse material will be routed to a sluice and only the fine material will be routed to your concentrator.
iCON is a family of products specifically designed to recover fine gold and provide the correct modular process to various regions of the world. iCON was designed by the professional engineers at Falcon Concentrators and uses the same patented technologies used at the largest mines in the world.
The heart of the iCON family are the world famous i150 and i350 Concentrators. iCON uses classification and enhanced gravity in its centrifugal concentrators to ensure that you are recovering the most gold possible.
iCON is supported by governments around the world due to its ability to recover gold without the use of mercury. iCON was designed for the United Nations Global Mercury Project to bring professional techniques to small miners throughout the world. iCON uses the same proven technology as the Falcon brand of professional mining products: it was designed by Falcons engineers and is now a product of iCON Gold Recovery Corp.
The iCON Concentrator is designed to capture all heavy minerals including Gold, Silver and PGMs and Mercury. It uses enhanced gravity to concentrate very fine, free minerals that are not recoverable using the traditional techniques of small scale and artisanal miners. The technology is based on the batch-type Falcon concentrator and designed by the same Falcon engineers that design concentrators for the largest mines in the world.
In operation, material is fed as a slurry of minerals and water into a rotating bowl that includes special fluidized grooves or riffles to capture the heavies. Periodically, a rich concentrate is rinsed out and requires further upgrading to be turned into a final gold product.
Throughout history gold processing has been plagued with inefficiency and contamination. Millions of dollars of fine gold have been discarded in the tails or washed down the creek due to inadequate processing. Other operations have long put the health of both workers, and our planet at risk with the use of mercury, cyanide and other dangerous chemicals. iCON technology successfully addresses both issues, ensuring that the highest percentage of gold is recovered and no hazardous chemicals are needed.
The most important factor in mineral processing is classification; the relative size of the gold you are processing must be known. Mineral processing is expensive and time consuming. Processing large material that is known to have no value, costs both money and time. With classification, time, energy and money will not be wasted processing excess material that is known to have no values. For example, if you know that your largest gold is .5mm then there is no reason to put 10mm material through your process. Also, the large feed will affect the efficiency of any process. The large material will hinder the recovery of the finer materials. For example, one miner improved his recovery from 40% to 70% simply by screening his feed from 8mm to 2mm. No gold was lost, because his largest gold was around 0.5mm. The iCON method will improve your process by screening your feed to the proper size (reducing the volume of feed) and increasing the percentage of gold that you recover.
iCON uses a 2 step process; classification and concentration. Your feed will be screened to 2mm (or less based on your results) before processing in the concentrator. Any material larger than the screen will pass over the nugget trap. This will give the user confidence that they are collecting the BIG gold while minimizing the feed to the concentrator and maximizing its efficiency.
In order to install your iCON you will have to consider the following: suitable footing, electrical supply, clean/pressurized water supply, feed method, tails removal method, concentration collection. You will also need to consider the height of the concentrator relative to the slurry input and tails output.
It is important to use the same size hose as the barb to supply this process water. A smaller hose, long hose or hose with bends/restriction will restrict the water flow and limit the pressure to the concentrator.
The process water should be fed from a dedicated supply line and pump. Connection to a manifold where other people may be using this same supply may cause wild fluctuation in the pressure and lead to unpredictable gold recovery.
zimbabwe platinum mining crushers and milling machine for sale from china
Zimbabwe has abundant natural resources, coal, chromium, gold, silver, iron, asbestos, lithium, and niobium, lead, zinc, tin, uranium, copper, nickel, etc. Coal, iron, chromium, and asbestos deposits are famous in the world for the large quantity. Zimbabwe has been a crazy plundering Africa wealth of western colonists, and it was referred as "the jewel in the crown" before it was independent. Coal reserves are about 27 billion tons. Iron reserves are about 250 million tons. Chromium and asbestos reserves are large. This country is lack of water resources. Main industrial categories are metal and metal processing, food processing, oil, chemical industry, drinks and tobacco, textile, paper making and printing, etc.
In 2008, the domestic political and economic situation continues to deteriorate and the international financial crisis, most mining companies are closed. Since the coalition government was establishment in February 2009, mining industry began to recover. Mining industry grew 26% year-on-year in 2011. According to the report, Zimbabwe platinum producer has regarded Engels's area underground mine as the company $258 million plan's first phase of expansion plans for the long term. Once realizing full production, the new platinum mining is expected to push up Zimbabwe mining company's ore annual output to 4.5 million tons, and the platinum output will be 5 tons.
For mining platinum ore in Zimbabwe, SBM supplies and evaluate equipment to make unbiased selections of the best equipment for this mining processing. SBM can provide the full range of capabilities to convert run of mine platinum to saleable products, integrating engineering and process know-how in development and optimization of plant designs for platinum that meets global environmental standards.
Platinum mining plant usually includes three main processing stages: crushing, grinding and beneficiation stages. The first two stages are used to get large scale raw platinum materials into fine size. Beneficiation plant will help to get fine powder materials into high grade and pure materials.
The main machine used in platinum mining plant has jaw crusher, cone crusher, impact crusher, mobile crusher and ball mill, vertical roller mill, ultrafine mill and mobile grinding plant. Of course, in the whole production line, it needs the auxiliary equipment to finish the whole processing, such as the vibrating feeder, vibrating screen, belt conveyor and so on. In beneficiation plant, all kinds of beneficiation machines will be used, like, separators, washing machine etc. These beneficiation machines will cooperate with main processing equipment to make the whole line for Zimbabwe platinum production line.
SBM is a professional mining machine manufacturer from China and our company has established good cooperation relationship with Africa countries, such as Zimbabwe, South Africa, and Uganda and so on. Our mining machines have helped local mining operators get much profit. Based on over 20 years' production experience, SBM has produced high quality and advanced mining machines for sale, crushing machine, grinding machine and beneficiation equipment.
Platinum mining jaw crusher is the major crushing equipment used as primary crushing machine in mining and quarrying industry. SBM jaw crusher machine belongs to the practical and economic equipment machine for mining operators. This primary crusher machine is designed to break all kinds of mineral ores with high crushing capability, low costs, high reduction ratio which makes it popular in over 100 countries.
SBM's cone crusher machine has the spring release system will allow the tramp platinum to pass without damage to the crushing chamber. The sealing system adopts the double dry oil and water sealing to separate the lubricating oil from stone dust to provide its reliable operating. Our platinum cone crusher has reliable construction, high productivity, easy adjustment and low operating costs.
Milling machine used in platinum processing line from SBM refers to the vertical roller mill. This grinding mill has easy access for replacement of runners, casing and segments of the rotating table without dismantling of the grinding chamber and separator. This grinding milling machine is used to get fine powder platinum materials in Zimbabwe.
Its fully-enclosed layout features high integration. It integrates the functions of high-efficiency sand making, particle shape optimization, filler content control, gradation control, water content control, and environmental protection into a single syst
treating chrome tailings for pgms
The Samancor dump operations contain about 500,000 ounces of PGMs at an estimated average non JORC compliant grade of 2.6 g/t. Sylvania director Zoran Marinkovic explains that it is not economically viable to convert its resource to a JORC compliant reserve as it would entail extensive drilling of the dumps. The grades are very variable, and the key operational parameter is ensuring we blend correctly to achieve the right grade of feed material to our plants.
Some of the material treated is Run of Mine (ROM) tailings and arisings, in addition to dumps which have been standing for long periods. In parts of some of these old tailings oxidation has taken place. Where this has occurred, the recovery of PGMs is lower. However, Marinkovic, who is a chemical engineer, says the oxidised material will still be processed and the response to this issue remains the same, that of blending to ensure the output concentrate grade is within the required range and that the chrome content is below a specified level. There is a saying that what a chrome extraction process likes the PGM extraction process does not like.
Nonetheless, the grade of platinum in the chrome dumps compares very favourably with the 0.7 g/t to 1 g/t of the traditional platinum dumps. It is because chromite sources such as the chromite-containing LG-6 reef are typically not mined for PGMs, which are discarded along with tailings.
Sylvania financial officer Louis Carroll says that the company will not limit itself to chrome tailings.In fact the biggest challenge Sylvania faces, once it builds up from current levels of 10,000 ounces a year of PGMs to its target of 70,000 ounces a year, is that of finding the resources to sustain and increase output, to ensure a production plateau as opposed to a peak.
We will be aggressive in the market to fill the gap to sustain production at 70,000 ounces a year, and will look all over to source material for our plants, Carroll says. This is where the companys interest in the North Everest surface mineable deposit could play a significant role in the future of the group.
Sylvania is exercising the option to acquire 100% of the project located on the Vygenhoek farm on the Eastern Limb, and which has a 5.1 million tonne resource with a grade of 4.7 g/t for 770,000 ounces of PGMs. It may develop the mine on its own though that is not the first prize. The optimum way forward would be to combine its project with the adjacent Eastern Platinum property if a deal can be done on the merger of the assets. This would result in a one million tonne per annum (mtpa) operation that would take between 18 months and two years to build. Water and power access still have to be resolved and, with a 1 MW power plant costing R2 million a month in diesel, this option has priced itself out as a contingency and grid supply is required. The operation would have a concentrator that takes the ore to 150 to 250 g/t. This concentrate would be sold to an off-taker and the operation would get a percentage of the LME price.
The key to Sylvanias success is its ability to economically separate chrome content from platinum, something that not many people believed was economically achievable. Sylvania has proven it can be done, and though it has four patents, most of the technology used is conventional.
The particle size is important for chrome separation as anything less than 75 micrometres causes difficulty in separating the two. We ensure the chrome content of the concentrate we deliver to the smelters is below a certain percentage. At our first plant, Millsell on the Western Limb on the property of Samancors Millsell mine, the target is less than 3% chrome content and the plant looks to achieve a figure of 2.8% chrome content. There are severe penalties if the grades of material and chrome content limits are not achieved, Marinkovic says.
At Millsell the feed for the plant is blended from five different sources to produce a 180 g/t to 200 g/t concentrate that is sold to a smelter, in this case the off-taker being Anglo Platinum. The concentrate from Sylvanias other currently existing plant, its Steelpoort facility on the Eastern Limb, is sold to Implats. The Millsell plant, located within a maximum six kilometres radius from the furthest tailings dump from which it obtains material, will complete the processing of old tailings in about three to four years. After that, it will continue processing of ROM material which will account for some 7,000 to 10,000 tonnes per month (tpm) over an expected Millsell life-of-mine of 25 years or longer. Sylvania aims to achieve about a 50% to 60% recovery rate, with 43% being achieved at Millsell.
Sylvania, which was formed in late 2005, processes the dumps through centralised chrome and PGM flotation plants, and its Millsell and Steelpoort plants have the capacity to each process 37,500 tpm. A larger 70,000 tpm plant, its Lannex plant is under construction. It is targeted to be operational at the end of 2008 and will process ROM and old tailings from the Broken Hill, Buffelsfontein and Spitzkop mine sites.
Another plant is to be established at Mooinooi. It will also have a 70,000 tpm capacity and is also scheduled to be operational by year end. The Lannex plant complex, which will comprise one plant and three sites will be modular, with two 35,000 tpm modules.
Unlike most juniors, Sylvania, whose headoffice team comprises 22 people, is doing the design and project engineering of its plant in-house, and one of its core strengths is its technical competence. We worked with a project engineering company when building our initial plant, but took the process in-house to better control costs, Carroll says.
Sylvanias groundbreaking Millsell plant is SCADA controlled and Marinkovic says that Sylvania has optimised its successive plants based on its experience with Millsell. One modification is that while Millsell is a widely spread out plant, later plants are more compact. Sylvanias Millsell plant manager works for Sylvania, but for the most part it is operated by contractors.
Millsell, though Sylvanias first project as operator, is not Sylvanias first project overall. The companys first project, which gave it entry to the sector, is a 25% interest in Aquariuss Chrome Tailings Retreatment Project (CTRP) located on the Western Limb near Rustenburg. The consortium constructed a purpose built plant at the Kroondal mine to extract PGMs from the tailings of the nearby Xstrata and LanXess chrome mines. The CTRP plant is managed by Aquarius Platinum and has been in production since January 2005.
The process at Millsell involves six stages, the first of which is the obviously the mining that produces the tailings. The mines, in upgrading the chromite content of their ore, produce a tailings stream that contains the majority of the PGMs of the ROM chrome ores. It is these chrome ores with elevated levels of PGMs that are treated.
This is followed by classification with material larger than 10 cm rejected. The milling stage, which features a ball mill, grinds the material to +0.63 mm with the fines bypassing the mill and reporting directly the next stage. The tailings and dump material, due to their fine particle size, mean that the coarse material accounts for only some 28% of the total with the rest being free issue. The material contains about 28% chrome content at this stage. The plant at Millsell processes some 60 to 70 tonnes per hour of material.
The material proceeds in slurry to the gravity separation stage, where the coarser material is separated from the fines by spirals. This stage is followed by thickening where all the thickener underflow proceeds to the flotation stage while the water is reclaimed for re-use. The process uses 360 litres of water per tonne, and this water is recycled, the end result being that less water finds its way to the final tailings site. Evaporation accounts for about 30% of the total water used and has to be replaced.
Then follows a conventional flotation stage, where the banks totalling 20 rougher cells achieve typically a 32% PGM recovery. This is followed by flotation banks comprising 10 cleaner and five recleaner cells that take the concentrate recovery level of about 44% of the contained PGMs. Collector reagents are used to make the PGMs aerophilic, depressors are used to make the chrome hydrophilic, in addition to the frother. The optimal use of reagents is determined by the initial blend of material entering the plant. If too much chrome is present then a great deal more depressor needs to be added to ensure the end product meets the smelter parameters.
The tailings are taken to a live tailings dam. In the future even these tailings may be reprocessed, since it all comes down to a matter of economics when determining what percentage of recovery is optimal, Marinkovic says. With its current retreatment of chrome tailings for platinum group metals, the AIM and ASX listed company is looking at a cost profile of US$300/oz, which will give it margins of between 70% and 80%.
An interesting feature of Sylvanias PGM mix is that during the second quarter of 2008, while its production split was 58% platinum to 26% palladium and 15% rhodium, more than half its revenue came from rhodium.
Sylvania is considering a listing on the JSE, but this would not be to raise cash in the near term as the company has R300 million on its balance sheet to invest in projects. More ounces could come from shallow mining at Everest North, additional tailings, and mergers and acquisitions. Apart from sourcing future resources to maintain production of PGMs at its planned elevated output, probably the biggest risk Sylvania faces is of becoming an acquisition target. Management may hope that the higher profile a JSE listing will provide will raise its valuation to discourage this, but more importantly a listing would be desirable to ensure that BEE transaction parties can achieve the tradability of their investment.