Showing posts about "processing"
Some ores occur in nature as mixtures of discrete mineral particles, such as gold in gravel beds and streams and diamonds in mines. These mixtures require little or no crushing, since the valuables are recoverable using other techniques (breaking up placer material in log washers, for instance). Most ores, however, are made up of hard, tough rock masses that must be crushed before the valuable minerals can be released.
In this process stage, the crushed material can be further disintegrated in a cylinder mill, which is a cylindrical container built to varying length-to-diameter ratios, mounted with the axis substantially horizontal, and partially filled with grinding bodies (e.g., flint stones, iron or steel balls) that are caused to tumble, under the influence of gravity, by revolving the container.
A special development is the autogenous or semiautogenous mill. Autogenous mills operate without grinding bodies; instead, the coarser part of the ore simply grinds itself and the smaller fractions. Tosemiautogenous mills (which have become widespread), 5 to 10 percent grinding bodies (usually metal spheres) are added.
Concentration involves the separation of valuable minerals from the other raw materials received from the grinding mill. In large-scale operations this is accomplished by taking advantage of the different properties of the minerals to be separated. These properties can be colour (optical sorting), density (gravity separation), magnetic or electric (magnetic and electrostatic separation), and physicochemical (flotation separation).
This process is used for the concentration of particles that have sufficiently different colours (the best contrast being black and white) to be detected by the naked eye. In addition, electro-optic detectors collect data on the responses of minerals when exposed to infrared, visible, and ultraviolet light. The same principle, only using gamma radiation, is called radiometric separation.
Gravity methods use the difference in the density of minerals as the concentrating agent.
In heavy-media separation (also called sink-and-float separation), the medium used is a suspension in water of a finely ground heavy mineral (such as magnetite or arsenopyrite) or technical product (such as ferrosilicon). Such a suspension can simulate a fluid with a higher density than water. When ground ores are fed into the suspension, the gangue particles, having a lower density, tend to float and are removed as tailings, whereas the particles of valuable minerals, having higher density, sink and are also removed. The magnetite or ferrosilicon can be removed from the tailings by magnetic separation and recycled. As the professional manufacturer of complete sets of mining machinery, such as classifier, Henan Hongxing is always doing the best in products and service. hammer crusher:http://www.hxjq-crusher.com/66.html
Flotation is the most widely used method for the concentration of fine-grained minerals. It takes advantage of the different physicochemical surface properties of minerals—in particular, their wettability, which can be a natural property or one artificially changed by chemical reagents. By altering the hydrophobic (water-repelling) or hydrophilic (water-attracting) conditions of their surfaces, mineral particles suspended in water can be induced to adhere to air bubbles passing through a flotation cell or to remain in the pulp. The air bubbles pass to the upper surface of the pulp and form a froth, which, together with the attached hydrophobic minerals, can be removed. The tailings, containing the hydrophilic minerals, can be removed from the bottom of the cell.
Flotation makes possible the processing of complex intergrown ores containing copper, lead, zinc, and pyrite into separate concentrates and tailings—an impossible task with gravity, magnetic, or electric separation methods. In the past, these metals were recoverable only with expensive metallurgical processes.
Magnetic separation is based on the differing degrees of attraction exerted on various minerals bymagnetic fields. Success requires that the feed particles fall within a special size spectrum (0.1 to 1 millimetre). With good results, strongly magnetic minerals such as magnetite, franklinite, and pyrrhotite can be removed from gangue minerals by low-intensity magnetic separators. High-intensity devices can separate oxide iron ores such as limonite and siderite as well as iron-bearing manganese, titanium, and tungsten ores and iron-bearing silicates.
The electrostatic method separates particles of different electrical charges and, when possible, of different sizes. When particles of different polarity are brought into an electrical field, they follow different motion trajectories and can be caught separately. Electrostatic separation is used in all plants that process heavy mineral sands bearing zircon, rutile, and monazite. In addition, the cleaning of special iron ore and cassiterite concentrates as well as the separation of cassiterite-scheelite ores are conducted by electrostatic methods.
Mineral processing refers to a number of interrelated procedures that are all aimed at extracting valuable material from ores. Many valuable minerals are mined as ores, which are rocks that contain useful substances. Mineral processing was done by hand in the past, though in modern times it is typically achieved through the use of heavy machinery. There are four main types of mineral processing, each of which uses a different method to separate valuable materials from ore gangue. The four different methods involve the reduction of ore particle sizes, the separation of particles by size, concentration of wanted minerals, and the removal of liquids from the solid minerals.
In broader terms, mineral processing consists of two functions. Firstly, it involves the preparation and liberation, of the valuable minerals from waste minerals and secondly, the separation of these values into two or more products, called concentrates. The term separation in this case is synonymous with concentration. These functions are carried out within the constraints of the following three rules.
1. The first rule deals with the conservation of mass. The total flow of the material into the process plant equals the total flow out.
2. The second rule relates to the quality or grade of the concentrate product. In practice, it is impossible to produce a concentrate consisting of only one mineral. As the professional manufacturer of complete sets of mining machinery, such as belt conveyor, Henan Hongxing is always doing the best in products and service. raymond mill:http://www.hx-crushers.com/p54.html
3. The third rule is a corollary of the second. It is impractical to recover all of the valuable minerals into the concentrate.
In order to separate the minerals from gangue (the waste minerals), it is necessary to crush and grind the rock to unlock, or liberate, valuable minerals so that they are partially or fully exposed. This process of size reduction is called comminution. The crushing and grinding process will produce a range of particles with varying degrees of liberation (Figure 2). Any particles that exceed a target size required for physical separation or chemical extraction are returned to the crushing or the grinding circuit.
The comminution process actually begins during the mining stage through the use explosives, excavators or scrapers for softer material. This is necessary in order to generate a material that is transportable by haul trucks or conveyors. Comminution in the mineral processing plant is carried out in a sequential manner using crushers and screens followed by grinding mills and classifiers. The various types of comminution equipment including their general application are described in detail below.
Ball mill’s the improved economic benefit: after improvement, material conveying uniform, and improves the production efficiency.
The copper ore is extracted, either through the open pit mines or underground mines. The beginning of the copper is mine by excavation blasting or crushing oxide and sulfide ore then. In the process of grinding, the copper ore is decomposed into sizes small grain of less than 25 cm in diameter by primary crusher and crushing that he pieces of nuts by Crusher or a crusher secondary finesse. Ball mill plays an important role in the process of Copper Ore Powder Making. Ball Mill is an effective tool to grind the nuts into powder size copper ore. There are two methods of grinding: the way dry and wet type. It can be divided into tabular type and type vibrant according to different forms of unloading.
As we all know, ball mill is a necessary and key equipment in the mineral processing of mining, and as with the ball mill, the revolving speed of a ball mill is the key factor of resolving its grinding efficiency .
However, in the actual work, the revolving speed of the ball mill is limited by the ratio of transmission device and other external conditions, which make it can’t reach the most suitable height, so it is generally easier to close to. As the professional manufacturer of complete sets of mining machinery, such as hammer crusher, Henan Hongxing is always doing the best in products and service. ore beneficiation:http://www.crusher-machine.com/n51.html
Advantages of vertical copper Ball Mill
Vertical ethical indent is a good preferred for grinding, as well as is at vast used in a concrete industry, electric power, metallurgy, containing alkali industry, as well as non-metallic vegetable industries. It can grub coal, marble, granite, kaolin, tough coke, etc. Therefore, it is additionally called straight spark indent or straight concrete mill.
The ball no longer block spiral groove, without the leakage phenomenon of feed, feeding capacity by improved before 12T / H to20T / H. Ball mill feed screw barrel after improvement, when output has reached13-15 ton, according to the production5T / H computing, year can obtain economic benefits 110000 yuan, and the renovation costs only 3000 yuan. When placed in use, belligerent materials have been a categorical tender element for a rabble in nation coverage. Then it rotates around a straight pivot line logging drum hung a stars stand. With centrifugal force by rotation, logging drum wings outward as well as presses discerning upon logging rings to assuage a ride of element functions in between a drum as well as harsh ring, which materials have been detected by rolling a drum logging as well as grinding. stone crusher
The processing of iron ore is a task that involves taking the raw ore and preparing it for use in the creation of a number of different iron products. There are actually several different processes that may be used to aid in this conversion of the raw ore into useful iron components. Most processes will involve some sort of crushing and grinding activity that results in small units that are easier to work with in terms of creating iron bars or even preparing the iron for smelting.
In most cases, the processing of iron ore will begin with some sort of crushing action. Different types of crushers are in common use today, including jaw crushers, impact crushers, hammer crushers, and cone crushers. Each of these types of crushing equipment are designed for use in specific situations involving the processing of iron ore. For example, hammer crushers are often used at mine sites when the yield from iron ore deposits is somewhat small.
After use of some form of crushing equipment, the processing of iron ore will usually involve grinding. Different types of grinding equipment produce everything from a fine dust to small pebbles, with the choice of grinder based on what type of further processing is involved to prepare the ore for its intended use. The grinding can sometimes occur at the site immediately after the crushing is finished, or take place in a processing plant in the event the yield from the excavation is more than can be managed with the smaller equipment designed for use at a mining site. As the professional manufacturer of complete sets of mining machinery, such as flotation cells, Henan Hongxing is always doing the best in products and service. ball mills:http://www.hxjq-crusher.com/20.html
Once the crushing and grinding are complete, the processing of iron ore will often involve some sort of filtering action before the final product is created. Filtering equipment will help remove any other types of rocks or other impurities that were not screened out during the early processing efforts. The end result is a raw iron ore product that is ready for smelting and the manufacture of iron goods and products that can be used in a number of different applications.
The main goal for the processing of iron ore is to take the ore extracted during the mining effort, break the ore into usable units and then purify those units before the actual smelting begins. Doing so makes it easier to produce a higher grade of iron that in turn can be used to create materials for use in everything from manufacturing lawn furniture to cookware to building materials. Typically, whatever processing is done must comply with governmental regulations that set standards for the type of iron that may be used in the manufacture of specific types of goods, especially iron products used in the creation of machine components or in materials used for building construction.