Vertimill is a unique product offered exclusively by Metso Outotec. Grinding efficiency, reduced media consumption, lower installation cost, minimal maintenance, and minimal liner wear make Vertimill the lowest total cost of ownership in many applications, substantially improving the profitability of concentrators.
Mechanically, Vertimill is a simple machine with an agitating screw suspended into the grinding chamber, supported by spherical roller bearings and driven by a fixed speed motor through a planetary gearbox.
Vertimill is an energy efficient grinding machine. They tend to grind more efficiently than, for example, ball mills with feeds as coarse as 6 mm to products finer than 20 microns. This provides up to a 40% higher energy efficiency.
As the particles are ground, they rise to the top of the mill and overflow into the separating tank. A change in the rotational direction of the slurry when it transitions from the mill to the separating tank causes turbulence which facilitates a settling of the coarser material.
The recycle system can reduce cyclone circulating load by allowing the mill to preferentially grind the coarser material. Also, the uprising velocity in the mill can be controlled by a recycle pump to affect the product size distribution, prevent over grinding, and reduce the circulating load from the cyclone.
Final product size is a factor of applied grinding power, flow rate, and slurry density. The effective operation of the Vertimill requires these parameters to be accurately and constantly monitored and adjusted to meet the required product specifications.
Conventional Ball and Tower Milling were not economic to grind below 25 microns, due to low energy efficiency, low power intensity and high media consumption. Further, the high steel media consumption in these mills was severely detrimental to flotation performance.
Investigations into fine-grinding started at Mount Isa started in the 1970s using conventional grinding technology to increase mineral liberation by grinding to fine sizes. These technologies were not only found to have high power consumption but also proved to be detrimental to flotation performance as a result of pulp chemistry and iron contamination from steel media. These poor results were revisited during pilot plant and tower mill testwork in the 1980s which also showed an inability of tower mills to economically achieve the required sizes.
It was clear that the solution to efficient fine-grinding did not exist in the minerals industry. So we looked for ideas to "crossover" from other industries that also ground fine particles pigments, pharmaceuticals, foodstuffs (e.g. chocolate). While these mills operated at a much lower scale and treated high value products they demonstrated the principle that stirring fine media at high speed was highly efficient. Perhaps the concepts could be developed to treat large tonnages of lower value materials?
In 1991 the introduction of a Netzsch laboratory stirred mill to the Mount Isa site was a turning point in fine-grinding and ultrafine grinding. The litre bench scale mill resembled a milk shake maker and used fine copper smelter slag as grinding media. Testwork on McArthur River ore started in 1991, and by January 1992, a small pilot scale mill, LME100, had been designed and installed at the Mount Isa pilot plant. The testwork showed that high speed, inert, horizontal mills could efficiently grind to 7 microns at laboratory scale providing major improvements in metallurgical performance. To make ultrafine grinding applicable to full-scale production a program of development was undertaken between Mount Isa Mines Limited and NETZSCH-Feinmahltechnik GmbH.
After 7 years of development and testing of prototypes in the Mount Isa operations, the IsaMill evolved. It was large scale, continuous, and most importantly robust because it was developed by operators. The crucial breakthrough was the perfection of the internal product separator this allowed the mill to use cheap natural media (sand, smelter slag, ore particles) and to operate in open circuit. These are significant advantages for operating cost and circuit simplicity. Scale-up was tested using trial installations at the Hilton and Mount Isa lead/zinc concentrators. By the end of 1994, the first full scale IsaMill (1.1MW) was installed in the Mount Isa concentrator.
In 1998 the rights for commercialisation of the IsaMill where transferred from Mount Isa Mines Limited to MIM Process Technologies (now Glencore Technology) and under an exclusive agreement with Netzsch. In December 1998, the IsaMill technology was launched to the metalliferous industry as a cost effective means of grinding down to and below 10 microns.
Moving stirred milling "from ink to zinc"was the hard part. The next challenge was to apply the same energy and processing advantages to mainstream grinding. This needed two further developments an even bigger mill and low-cost, competent ceramic media. The first M10,000 IsaMill was installed in South Africa in 2003, and Magotteaux developed KERAMAX MT1 ceramic media specifically for IsaMilling in 2005.
Since then, the 3MW M10,000 has become the most commonly installed IsaMill. The power installed in regrind and coarse grinding applications has quickly outstripped that used in ultra fine grinding. This remarkably rapid adoption in coarse grinding reflects the robustness and simplicity of IsaMill technology.
In just 11 years since the first IsaMill was installed at the Hilton Concentrator, IsaMills increased their capacity 16 fold from 205kW to 3MW and their volume has increased 20 times. This rapid increase in capacity can be compared to autogenous milling technology which although available since 1907 took 19 years (from 1940 to 1959) to increase power draw by just 6. (from Burford Fine Grinding and Project enhancement, Innovative Mineral Developments AUSIMM 2004)
By the end of 2010 there will be 81 IsaMills operating with over 130MW of installed power. Feed sizes are as coarse as F80 of 250m. The product sizes ore as low as P80 of 7m for materials ranging from lead and zinc sulphides, platinum concentrates, industrial minerals, iron oxide and refractory gold concentrate. Such a new technology has been embraced by those operations that rely on grinding to achieve metal recovery.
Feed to the IsaMill passes through 8 consecutive grinding stages between the discs before it reaches the internal classifier. Other mills with just one grinding stage require closed circuit cyclones and high recirculating loads and still don't produce product size distributions as steep as the IsaMill.
The product separator is one of the key advantages of the IsaMill design. The 8 consecutive grinding chambers, and high tip speed of the separator means that the mill constantly delivers sharp sizing performance. There are no screens or trommels to fail or block, any particle that leaves the mill must escape the same centrifugal forces. A further advantage of this mechanism is that it allows the IsaMill to use a wide range of media type and size. Even if a portion of the media degrades early, it can exit the mill without blocking screens, with the remaining competent media retained for grinding. In contrast, mills closed by fine screens are limited to using only the most competent media.
The type of media used in the IsaMill ranges from effectively 'free' media source including smelter slag and coarse SAG Mill product, to low cost locally available sands through to more expensive, high quality ceramics. The best choice for any application is simply a question of economics, taking into account cost and quality of local media, power efficiency and capital cost. While higher quality media is more expensive, it is usually more power efficient, reducing the installed power requirements and operating cost.
The patented internal product separator unique to the IsaMill retains all media inside the mill and negates the need to use screens and cyclones to retain media. IsaMill operations can take advantage of this feature which translates to an ability to use a low cost, but relatively low quality grinding media such as silica sand, river pebble, smelter slag or fine primary mill scats (autogenous milling). This means low media cost, with power efficiency still better than conventional grinding.
While natural sands and slags have a wide range of performance as media and need to be tested for competency, power efficiency and consumption rate before being selected there are also a number of standard natural medias are available (e.g. sand). Performance of these medias is well known and predictable. In general natural medias, due to their grain size, are restricted to fine grind sizes (e.g. below 25 microns). Coarser grinds favour the use of manufactured media, which can be produced to have a desired and reproducible size and strict quality control. Further, the high sphericity, roundness, surface smoothness and SG mean that much higher power efficiencies can be achieved than for natural media. The power efficiency of coarse IsaMilling with ceramic media is much higher than for conventional ball or Tower Milling.
Until recent years ceramic media had been uneconomic for grinding. This changed with the development of Keramax MT1 grinding media by Magotteaux International in cooperation with Glencore Technology. The unique properties of MT1, including low friction, high SG and very low wear rates, mean it can achieve exceptionally high grinding efficiency and low cost for coarse feeds. The first industrial application combining Keramax MT1 and IsaMill technology was commissioned in late 2005.
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: