gold ore grinding mill sale

using ball mills to extract raw gold from ores

using ball mills to extract raw gold from ores

Placer mining and lode mining are very different. Whereas placer gold has been released from within the rock and is generally free from any significant matrix, lode gold presents different challenges. While gold may be present in ore, it must somehow be released for proper extraction.

As a result, a number of machines have been invented to bring about maximum results with regard to obtaining the much needed resource, gold. One of such equipment is the ball mill. Below is the write-up of how a ball mill works, is used to crush ore and an explanation regarding its effectiveness in gold mining.

First of all, in order to get the best out of how this particular equipment is used it is important to get acquainted with knowledge on what it is, and is made of. Hence, a mill is a piece of equipment used to grind ores. Its major purpose is to perform the grinding and blending of rocks and ores to release any free-gold that is contained within them.

At major mines, the mill was the critical equipment that was required to process the ores that were extracted from deep underground. Many early mines used stamp mills, but many operations today find that ball mills are more functional for smaller operations and perform well with the modern equipment we have available now such as combustion engines.

To perform its functions, the ball mill operates on the principle of impact and attrition. This principle entails that the balls are dropped from near the top of the shell in order to bring about size reduction impact.

The major components of the ball mill include a shell that is hollow and is suspended on its axis to bring about rotation. The axis of the shell can be suspended horizontally or at an angle to the horizontal.

The shell is filled with quite few, but reasonable amount of balls which do the grinding process, and can be made of steel such as chrome steel and stainless steel. They can also be made of ceramic or rubber depending on their targeted material to be ground.

Its major operations are categorized into two, namely the dry and wet processes. Through those processes the machine is able to perform its functions of grinding the crushed materials. One of such functions, is that which is witnessed when grinding different types of ore, such as gold ore.

Now here is what one must know with regard to how the ball mill operates. The drum of the mill (shell) is suspended on two self-aligned rollers. Then the material to be worked on is loaded through the hopper.

From there, the mill is driven using a motor with a clutch, gearbox and the flexible coupling. The mill is then lifted to a certain level of height as it rotates. It is from that height that the balls begin to freely fall or roll down in order to grind the material that has been loaded.

After the material is ground, it is then removed from the mill depending on the discharge method used on the machine. For example, there are center unloading mills as well as unloading through the grille mills.

For the center unloading mills, the ground material is discharged through a hollow unloading trunnion using a free sink. To make it more efficient the pulp level in the drum should at least be above the level of the lower generating trunnion for unloading.

On the other hand, mills whose unloading is done using the grid consist of a lifting device which helps to unload the crushed material. For this reason, in such a mill the slurry level is likely to be lower compared to the unlading trunnion level. In such a mill, a grid with openings used for unloading crushed material is located in the unloading end of the drum.

To crush the gold ore in order to obtain pure gold, the large ore of gold is fed into a jaw crusher or mobile jaw crusher for the primary crushing process. The crushing process acts as a medium of screening the fine gold ore. It is then sieved using the vibrating screen and later sent through the use of a conveyer belt.

The ore is sent into a single-cylinder hydraulic cone crusher for the secondary crushing. Thereafter, the gold ore is transferred to a multi-cylinder hydraulic cone crusher, where the ore is crushed further into finer material. From there, the crushed gold ore is sent to a ball mill, evenly as it passes through a vibrating screen for grinding.

From the ball mill, the gold ore powder is subjected to the process known as beneficiation for further crushing before classification and floatation processes. Most commonly, professional mining operations will use a shaker table at this point. These are extremely effective at capturing tiny particles of free-gold that has been released from the ores.

gold ore rock crusher impact flail processing quartz crushing mill - gold-mill.com

gold ore rock crusher impact flail processing quartz crushing mill - gold-mill.com

These portable impact mill rock crushers that we produce are high quality, made in the USA impact mills that crush rocks and realease gold bearing ore. These

are made of the highest quality, super thick, high carbon, industrial steel materials for years of trouble free use. We then use an industrial quality high

temperature powder coating to protect the mill from corrosion and to keep its beauty for many seasons to come. We also show you how to crush, grind

and process your gold ore bearing quartz material and offer information on gold recovery with these units. (800) 688-4080

NEW Gold Stryker GS-4000 HV (High Volume) is a high output / dual adjustable discharge / heavy duty version flail impact rock crusher gold mill that is very portable and perfect for the small gold mining operation. The Gold Stryker GS-4000HV uses a 13 HP Honda Industrial engine for many years of trouble free use. It can process and crush up to 3-3.5 tons of material in a day, all the way down to #300 mesh through the mill to release the gold. $6499 Sale

(The quantity of material the GS can process depends on the size, density and hardness of the rock being fed into the hopper. The smaller the rock, the more material you can run in a day.)

The New Gold Stryker GS-5000HD is a large flail impact rock crusher gold mill that is very portable and perfect for the small gold mining operation The Gold Stryker GS-5000HD uses a HP Honda Industrial engine for many years of trouble free use. It can process and crush up to 5+ tons of material in a day, all the way down to #300 mesh through the mill to release the gold. $7899 Sale

(The quantity of material the GS can process depends on the size, density and hardness of the rock being fed into the hopper. The smaller the rock, the more material you can run in a day.)

Gold Stryker GS-7000-LD is a very large flail impact rock crusher gold mill that is very portable and perfect for the small gold mining operation. The Gold Stryker GS-7000-LDuses a large 25 HP Honda Industrial engine for many years of trouble free use. It can process and crush up to 7 tons in a day, all the way down to #300 mesh through the mill to release the gold. $15999 Sale

(The quantity of material the GS can process depends on the size, density and hardness of the rock being fed into the hopper. The smaller the rock, the more material you can run in a day.)

Our Gold Stryker impact rock crusher mill is a very portable unit and a serious work horse. Not a small toy for testing a few rocks. They will also process the gold

daily. Many of our customers are located in South America, Canada, Africa, Alaska, The Bahamas and other far away places. If you can see this web page, then we can ship to you!

laboratory grinding mill

laboratory grinding mill

Our Laboratory Grinding Mill comes standard with a 1 HP motor and optional variable speed drive ranging from 1 to 100 RPM. This Grinding Mill is fully enclosed with sound dampening material for a quiet workplace. The sheet metal steel fabrication provides full enclosure around the main frame and door. The yoke (grinding cylinder) is totally balance and vibration-free in its horizontal position of operation. Minimal effort is needed to swing it from horizontal to vertical position (loading/unloading). A unique feature this grinding mill has is the possibility to use different cylinders for research or pilot plants tests. Specifically, we offer different size of cylinders from 5 (127mm) inside diameter by 12 (305mm) long to 9 (229mm) diameter by 22 (560mm) long. All grinding mills cylinders are fully interchangeable and can be mounted/ removed rapidly. The cover is of a unique design that automatically seals the cylinder and is quickly mounted/removed. Another feature of this Grinding Mill are its heavy duty castors (wheels) for ease of laboratory movement/mobility.

Ore Grinding Mills are used for the fine grinding as the last step in the reduction of an ore prior to concentration (gravity or flotation) or cyanidation. Practice varies, depending upon the type of ore and the amount of reduction required. In addition, some of the older properties continue with methods that perhaps are not considered the best in light of recent improvements but that cannot be economically changed because of capital outlay. Present grinding practice is closely linked with classification, so that some overlapping of subject matter occurs. In this chapter some of the theory of grinding, different types of equipment, and flow sheets are discussed.

Most of the tonnage milled today is ground in one of the following types of equipment or a combination of two or more: ball mills, tube mills, rod mills, and stamps. Chilean mills and Huntington mills are used only in a few isolated cases today.

The term ball mill is generally used to refer to a cylindrical mill whose length is less than, equal to, but not much greater than its diameter. It was initially developed for relatively coarse grinding, but by using it in closed circuit with a classifier its use has been extended for fine grinding.

Ball mills have shells of cast iron or steel plates and are carried on hollow trunnions. Ore is fed through a scoop, drum-type, or combination feeder at one end and is discharged from the opposite trunnion.

Ball mills may be arbitrarily classified into two types, according to the method of pulp discharge. In high-level or overflow mills the pulp level builds up until it overflows and discharges through the trunnion. High- level discharge mills are made by a large number of manufacturers throughout the world. Low-level mills are typified by the Allis-Chalmers andMarcy (see Figs. 14 and 15) grate-discharge mills. The discharge end is fitted with grates; between the grates and the end of the mill are radial lifters which act as a pump to lift the discharge to the hollow trunnion. Drive is by spur or herringbone gear, direct connected or belt driven.

Ball mills are built in sizes ranging from small laboratory mills to a present maximum of 12 ft. diameter by 12 ft. long, the latter requiring close to 1000 hp.Liners are usually of manganese steel, of chrome steel, or white iron, 3 to 6 in. thick. Corrugated and shiplap construction is commonly used to increase the grinding action.

The Hardinge mill (see Fig. 16) differs from most ball mills in that conical ends are added to the cylindrical portion of the mill. The cone at the feed end has a larger open angle than that at theopposite end. Its makers state that the large balls concentrate near the feed end of the mill where the coarsest ore collects and the smaller balls act on the finer ore.

Rod mills (see Fig. 17) follow the general dimensions of tube mills with diameters from 3 to 6 ft. and lengths from two to three times their diameter. They differ from ball mills in that steel rods 3 or 4 in. shorter than the mill length inside the liners are used as grinding media. Rod mills are often run on tires and rollers instead of trunnions or on one trunnion and one tire and set of rollers.

Low-level discharge is obtained on Marcy rod mills by having a beveled annular ring at the discharge end. A stationary steel door fits close to this beveled ring and serves to hold the rods in the mill while pulp discharges between the mill and the door.

The distinction between tube mills and ball mills is not somarked as their names indicate. Mills from 4 to 6 ft. in diameter and from 16 to 22 ft. long are usually termed tube mills. This was the first type of rotary mill for metallurgical purposes. Because of the necessity of completing the grind during one passage (open circuit) of the ore through the mill, it was built with a large length-diameter ratio. The tube mill is still largely used in South Africa and to some extent in North America for fine grinding generally following some other primary mills.

Tube mills are usually supported on hollow trunnions, the feed entering through a feed scoop at one end and discharging through the other. Drive is by a large gear fitted over the mill shell. Various types of liners are used, as in ball mills.

All rotary mills must be fitted with some kind of replaceable liners. Chrome steel, manganese steel, and white iron are generally used. Shapes designed to give a corrugated or shiplap surface to the interior of the mill are often used to prevent slippage of the ball load. Pocket liners arealso common. These liners have pockets in which the balls become lodged to form the wearing surface.

Rubber liners have been tried experimentally but have not been adopted by the industry. According to Taggart, no fully satisfactory method of holding the liners in place was worked out, utility was limited to fine feeds and small balls, mill capacity was reduced, and while a slightly higher grinding efficiency was shown in comparative tests with steel liners, there was no indication that possible increased wear for rubber would offset its far greater cost.Silex liners with flint pebbles for grinding media are sometimes used where iron contamination must be avoided.

The grinding that takes place in mills of this type is usually ascribed to two actions, impact and attrition, although some authors do not believe that a sharp line of demarcation can be drawn between the two actions.

In rod mills there is line contact between the rods, there is less grinding by impact, and the action resembles that of crushing rolls. As a result, a rod-mill product usually contains a greater percentage near the limiting size with less extreme fines than ball or tube mills.

In selecting the correct grinding media it is important that the rods or balls supplied be large enough to break the largest particles of ore in the feed, and as already discussed, a seasoned load composed of balls of all sizes, which is the condition found in a mill that has been operating for some time, gives better grinding efficiency than a new charge.

The volume of the charge is limited to a maximum of about 50 per cent of the mill volume. If the charge is too large, its center of gravity shifts too near the axis of the mill and the power input falls.

The speed of the mill is limited by what is known as the critical speed. This is the speed at which (assuming no slippage) the charge starts to cling to the liners, or to centrifuge. It is given by the formula.

The percentage of solids in the pulp is usually maintained at 60 to 75 per cent, the principle being to keep the volume percentage of solids as high as possible without loss of mobility of the charge. The correct proportion of water present will depend on the kind of ore being handled, slimy ores in general requiring a higher dilution than ores that have a low slime content.

The size of mill required for a specific grinding problem will depend on the character and size of the feed and the product desired and whether open- or closed-circuit grinding is desired. An accurate estimate of capacity can be made only by an engineer familiar with the proper evaluation of the factors involved.

For rough estimating purposes Table 6 gives approximate capacities grinding to 48 and 100 mesh for several size mills. Connected horsepower is also shown. These figures are for what would normally be considered average siliceous ore and for nominal circulating loads of 2 or 3 to 1.

These capacities may be reduced by as much as 50 per cent in the case of a hard, tough ore which is highly resistant to grinding, and for this reason considerable thought has in recent years been given to methods for determining the relative grindability of different ores and to correlating laboratory figures with plant performance. F. C. Bond has published comprehensive grindability data based on work carried out by the Allis-Chalmers Manufacturing Co. and grindability tests are a regular part of the testing procedure of the Dorr Company at the Westport, Conn., laboratories.

When the tube mill was first introduced, grinding was done in open circuit; i.e., the ore was ground to pass the limiting screen size by one passage through the mill. It was found, however, that if sufficient time of contact between the ore and grinding media were provided to ensure that no unground particles (or oversize) discharged from the mill, an excessive amount of fines were produced. This meant that the ore was ground much finer than necessary and mill capacity was correspondingly reduced.

The difficulty was overcome by placing a classifier in the circuit to separate out oversize from the mill discharge and return it to the mill feed. In closed-circuit grinding no attempt is made to finish the grind in one passage through the mill, but every effort is made to remove finished material as soon as it is released, thus reducing over-grinding and preventing the fines from hindering the grinding action on yet unreduced particles. In this way the tonnage that a given mill will grind is much greater than it is possible to grind in open circuit.

By using wide classifiers with high raking capacity, circulating-load ratios are now being carried to 4:1 or higher. The direct result of the increased capacity is reduced power, liner, and grinding media consumption per ton of finished ore.

There is, of course, a limit as to how large a circulating load can be carried in practice. While capacity continues apparently to improve, though at a decreased rate, it becomes increasingly difficult to move the growing volume of material through the system.

There is some controversy in the literature as to the definition of ratio ofcirculating load. The term used by most millmen is the ratio of sand tonnage returned to the mill to the tons of original feed.

If the mill-classifier circuit is fed into the classifier instead of into the mill, the sand contains oversize from the original feed as well as oversize from mill discharge, and thus the definition is not entirely accurate. The ratio of circulating load can be calculated from screen analyses by using the following formulas:

Circulating-load ratio = d o/s d where d = cumulative percentage 0n any mesh in the mill discharge o = cumulative percentage on same mesh in the classifier overflow s = cumulative percentage on same mesh in the classifier sand

There are many types of flow sheets in use today. The tendency in new mills is to crush relatively fine ( to in.). Single-stage ball mills in closed circuit with classifiers are used for grinds coarser than 48 mesh, but when a finer product is desired, two stages of ball mills in closed circuit with classifiers is usual. Efficiency must necessarily be sacrificed to some extent in small mills by capital requirements, and even greater reduction ratios are justified in a single-stage grinding unit.

With the large classifiers used for high circulating loads it is quite often necessary to use some kind of auxiliary device to complete the closed circuit. A large motor-driven scoop lifting the mill discharge to the classifier has been successful.

Stamp mills were built to parallel the operation of a mortar and pestle, working continuously and on a large scale. Ore is fed into a mortar and is crushed by the dropping of the stamp on a die at the bottom of the mortar. The crushed ore discharges through a screen in the side of the mortar.

The shoe that forms the wearing surface on the dropping stamp is attached to a steel stem and is replaceable. The stem is lifted by a cam operating against a tappet which is bolted to the stem. A common camshaft activates usually five stamps in a battery.

Milling was done in unique, crude wooden stamp mills developed by the ingenious Antioquenan miner. Made entirely of hand-hewn hardwrnod (except for cast-iron shoes, several bolts, and a few nails) these molinos Antioquenos have a stamp duty of approximately 0.4 tons per 24 hr. They are powered by overshot water wheels, 18 to 24 ft. in diameter, mounted directly on the 18- to 24-in. wooden camshaft of the mill. Up to 56 drops per minute can be obtained with a water-wheel speed of 14 r.p.m. The stamps, 6 by 7 in. by 14 ft. in dimensions, weigh 450 to 500 lb. including the cast-iron shoe. The mills are usually built with three stamps to the mortar box and as many as three sets (nine stamps) per mill. Battery-box screens are usually made of tin from 5-gal. gasoline cans perforated with a small nail. Stamp guides, cams, and the hardwood camshaft bearings are lubricated with beef tallow.

The stamp mill was originally devised as a combination grinding and amalgamating device before the days of cyanidation. Its use continued with theintroduction of the cyanide process, where it was well suited to the comparatively coarse crushing used, the distribution of the ground pulp over amalgamation plates, and the steps of separate cyanidation of sand and slimes that followed. As the all-sliming method became more generally adopted, however, with the need for fine grinding in ball mills and preferably in cyanide solution, the stamp mill tended either to be used as a secondary crusher or to be replaced altogether by dry-crushing equipment.

These two types of mill are practically obsolete. In these mills rollers driven from a central gear-driven spindle revolve around a pan. In the former the rolls crush against a ring in the bottom of the pan, and in the latter centrifugal force holds the rollers against the ring at the side of the pan. Chilean mills were used at the Golden Cycle up to a few years ago for grinding roasted ore.

ball mill for sale | grinding machine - jxsc mining

ball mill for sale | grinding machine - jxsc mining

Ball mill is the key equipment for grinding materials. those grinding mills are widely used in the mining process, and it has a wide range of usage in grinding mineral or material into fine powder, such as gold, ironzinc ore, copper, etc.

JXSC Mining produce reliable effective ball mill for long life and minimum maintenance, incorporate many of the qualities which have made us being professional in the mineral processing industry since 1985. Various types of ball mill designs are available to suit different applications. These could include but not be restricted to coal mining grate discharge, dry type grinding, wet mineral grinding, high-temperature milling operations, stone & pebble milling.

A ball mill grinds ores to an end product size of thirty-five mesh or finer. The feeding material to a ball mill is treated by: Single or multistage crushing and screening Crushing, screening, and/or rod milling Primary crushing and autogenous/semi-autogenous grinding.

Normal feed sizes: eighty percent of six millimeters or finer for hard rocker eighty percent of twenty-five millimeters or finer for fragile rocks (Larger feed sizes can be tolerated depending on the requirements).

The ratio of machine length to the cylinder diameter of cylindrical type ball mills range from one to three through three to one. When the length to diameter ratio is two to one or even bigger, we should better choose the mill of a Tube Mill.

Grinding circuit design Grinding circuit design is available, we experienced engineers expect the chance to help you with ore material grinding mill plant of grinding circuit design, installation, operation, and optimization. The automatic operation has the advantage of saving energy consumption, grinding media, and reducing body liner wear while increasing grinding capacity. In addition, by using a software system to control the ore grinding process meet the requirements of different ore milling task.

The ball mill is a typical material grinder machine which widely used in the mineral processing plant, ball mill performs well in different material conditions either wet type grinding or dry type, and to grind the ores to a fine size.

Main ball mill components: cylinder, motor drive, grinding medium, shaft. The cylinder cavity is partial filling with the material to be ground and the metal grinding balls. When the large cylinder rotating and creating centrifugal force, the inner metal grinding mediums will be lifted to the predetermined height and then fall, the rock material will be ground under the gravity force and squeeze force of moving mediums. Feed material to be ground enters the cylinder through a hopper feeder on one end and after being crushed by the grinding medium is discharged at the other end.

Mining Equipment Manufacturers, Our Main Products: Gold Trommel, Gold Wash Plant, Dense Media Separation System, CIP, CIL, Ball Mill, Trommel Scrubber, Shaker Table, Jig Concentrator, Spiral Separator, Slurry Pump, Trommel Screen.

gold mining equipment

gold mining equipment

911MPE hassmall gold mining equipment for sale andmore specifically mineral processing equipment. Our equipment is best used in small scale extractive metallurgyoperations operated by small miners or hobbyist prospectors and mining fanatics. 911MPE offers gold mining equipment as well as processing equipment applicable to most any base metals: copper, lead, zinc, nickel, tin, tungsten and more. For the relatively small size of equipment offered, sample preparation and metallurgical laboratories can economically buy good alternatives to the usually unaffordable equipment for sale in the classic market place.

911MPE has for target market what mining professionals consider the pilot-plant scale mining operation or artisanal mining operations with a focus around under 500TPD. Metals you can extract include: gold, silver or other of the precious group as well as the classic base metals; copper, lead, zinc, nickel, molybdenum. Much of our ultra-small scale equipment allows you to process from just a few kilo (pounds) per day and work on your passion for a small budget.

You can buy from us mineral processing equipment starting from crushing, grinding, classification, dredging, gravity separation, flotation, pumps, water treatment and smelting. A line of ovens, furnaces and laboratory equipment is also available.

Making a complete list of gold mining equipment starts with defining the type of gold mining you are doing and the budget you have at your disposal. The type of mining relates to hard rock,eluvial, or placer; alluvial deposits. The capital budget you have to invest in buying your equipment with dictate the scale at which you want to mine and influence the long-term operating costs of your mining operation.

Since most of the information online provides lists of gold mining equipment for amateur level mining with equipment like: gold pans, metal detectors, mini sluice box, blue bowl, geologist rock pick, soil scoop, hand screens/classifiers. The items listed just now fall closer to gold prospecting tools and equipment than actual mining.

I will present here what I consider are major equipment lists for 3 types of mining operations. Remember now, a metallurgist is writing. This will not be flawless and since my speciality is process equipment, that is mostly what will be discussed.

Some amateur level gold prospecting equipment such as metal detectors are often classified as mining equipment by small miners/prospectors operating as a hobby. These items include but are not limited to:

buy ore ball mill for mineral processing | iron & gold ore ball mill

buy ore ball mill for mineral processing | iron & gold ore ball mill

Ore ball mill sometimes called ore grinding mill, is generally used in mineral processing concentrator, processing materials include iron ore, copper ore, gold ore, molybdenum ore and all kinds of nonferrous metal ore. The core function of the ore ball mill is to grind the materials, and also to separate and screen different mineral materials, and to separate the tailings, which is very important to improve the quality of the selected mineral materials.

The ore ball mill designed by our company, which is represented by gold ore ball mill and iron ore ball mill, is manufactured with high-quality materials and advanced technology. They have the characteristics of high efficiency, energy-saving, green environmental protection, simple operation, stable operation, and low failure rate, and have a good reputation in the industry.

The crushing ratio of the ore grinding mill is very large, and it is easy to adjust the fineness of the grinding product. The ore grinding mill has strong sealing performance and can be operated under negative pressure. It is widely used in chemical industry, metallurgy, new building materials and other fields.

We offer different types of ore ball mills for customers to choose from. There are energy-saving ore ball mill, dry and wet ball mill,wet grate ball mill, andwet overflow ball mill. Customers can choose to purchase according to material conditions.

Mineral processing is the most important link in the entire production process of mineral products. It is a process of separating useful minerals from useless minerals (usually called gangue) or harmful minerals in a mineral raw material by physical or chemical methods, or a process of separating multiple useful minerals The process is called mineral processing, also known as ore processing.

The first step in the ore processing is to select the useful minerals. In order to select useful minerals from ore, the ore must be crushed first. Sometimes, in order to meet the requirements of subsequent operations on the particle size of materials, it is necessary to add a certain ore grinding operation in the process.

The preparation before beneficiation is usually carried out in two stages: crushing screening operation and mineral classification operation. Crusher and ore ball mill are the main equipment in these two stages.

As a ball mills supplier with 22 years of experience in the grinding industry, we can provide customers with types of ball mill, vertical mill, rod mill and AG/SAG mill for grinding in a variety of industries and materials.

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