Mining Plant Machines Used Mineral Solution And Recycling Plant
Gold Mining Plant in SBM is used for crushing & milling project in Chile construction & quarry & mining processing. The series of crushing plant is designed because mineral mining crushing is always a common but low efficient process. Welcome to SBM - Professional Gold Mining Plant in Chile Supplier.
•According to the investigation, many gold mines of Chile are types of Copper ore and Gold ore mines. So Gold Ore mining process in Chile is not only gold mining but gold mining and copper ore mining processing.
•Copper and gold mine is a skarn deposits. Divided by ore-bearing rocks: copper carbonate-type gold ore, the gangue minerals garnet - epidote-quartz-plagioclase granulite. The main minerals of gold and semi-naked bare gold, fine gold silver monomer and a small amount of gold exists in the form. Most of the copper mineral malachite CuCO3 · Ca (OH) 2, there is a very small amount of bornite and copper blue and so on. The oxidation rate was 98%, and a highly oxidized ore.
Jaw Crusher for Primary Gold Ore Mining Plant
•As what I say above , Jaw crusher is widely used in Chile gold ore mining process. For jaw crusher is of high efficience , easy mantenance , cheap spare parts and other features.
•In the copper gold mine processing , jaw crusher is mainly used as primary (first) crushing machine when vibrating feeder takes big rock blocks.
•Just the processing above? Of course not , jaw crusher is designed for most of medium hard rock (barytes, salt, silica sand, iron ore, alunite ore, basalt, bauxite , gold ore, silver ore, granite , feldspar , gypsum , etc.) crushing and breaking process in quarry , mining, mineral solution and recycling plant, construction, railway building , industrial application site. With the benifit of Easy and cheap character , jaw crusher is suitable for every quarry miner , industry manager.
Optional Gold Mining Equipment for Chile Copper and Gold Mining
Primary crushing of gold processing is only the first step of crushing process. Even the secondary crushing processing is. Even more, ball mill for gold mining or raymond mill for gold ore grinding, mtm grinding mill is good partner after crushing processing to go on with the next industrial grinding or pulverizing processing.
Of course, one production line is not a complete system without vibrating feeder, belt conveyor, vibrating screen, sand washer (used for washing bits of rocks).
Gold Processing Plant,Mobile Gold Mining Plant For Sale-Gold Plant
To separate the gold through the ore collected through the diggers from the gold mining machine and tools, the ore was 1st crushed with a sequence of hammers from the stamper head. The crushed ore was then operate more than copper plates that experienced been treated with cyanide after which tinned with "quick-silver" (mercury). Mercury includes a substance affinity to gold and therefore catches it. The resulting mixture was then heated to evaporate the mercury right up until only the gold remained. This technique of extraction was applied for several many years even though it absolutely was normally accepted that it absolutely was only 60% effective.
Gold Mining Processing
1.Rock is eliminated through the mine.Rock that contains gold, is hauled for the Crushing Facility. Rock without the need of gold is used for the overburden storage space areas.
2.Large haul vans are applied to proceed the rock through the Mine for the crushing Facility, or for the overburden storage space areas.
3.Ore is processed on the two point crushing and grinding Facility,and hauled for the Valley Leach Facility.
4.The Valley Leath Facility may be a lined, zero discharge place in which dilute sodium cyanide procedure option dissolves the gold, and is also captured from the bottom in the lined area.
5.The gold is recovered through the procedure option having a carbon adsorption process. The last product or service may be a gold and silver key named Dore.
Mobile Gold Processing Plant For Sale
SBM Mining and Quarry Machinery CO.LTD has always been focusing on quarry solution and mineral mining processing solution , which has formed a lot of successful mineral ore crushing and grinding plants designs.
Secondary Iron Ore crusher crushes stones into smaller size and usually they can get used. But more often the products of secondary crusher get screened by vibrating screen and whose can fit the requirement will leave this process and become the final product and the others will go back to secondary ore crusher or even primary crusher to get crushed.
Finally, Iron Ores all become the right products . Tertiary crusher is usually used in special rock crushing process. Tertiary crusher will process stones into much smaller size than secondary crusher. We usually choose mobile crusher or portable crusher is this process.
Coal Crushing Plant,Coal Grinding Process,Coal Plant,Coal Powder Plant
The feeders load the ROM coal onto a reclaim conveyor that transfers the coal into the breaker station. Initial cement mill process is conducted through the rotary breaker where the coal is sized to minus 38 millimeters. Oversize material, mainly rock, is conveyed to an open, on-ground storage pile and then trucked to the existing coarse reject disposal facility. After the removal of the oversize material in the breaker, the plant feed is conveyed to the 1,800-tonne raw coal silo. Raw coal is recovered from the silo by four vibratory feeders onto the coal processing plant feed conveyor, which is equipped with a tramp iron magnet and a belt scale, and conveyed to the desliming section of the gold processing plant.
The fine raw coal is separated into clean coal and fine refuse in a bank of five 8.5 cubic metre capacity flotation cells. Reagents are required for this flotation process. The clean coal froth is passed to vacuum disc filters for dewatering. The filter cake is then discharged from the disc filters and combined with the clean coarse coal on the clean coal conveyor for transport to the thermal dryer, where the coal is currently dried during winter months. The thermal dryer is located in a separate building adjoining the coal processing plant and fuelled with natural gas.
Raw coal is fed through a central coal inlet at the top of the pulverizer and falls by gravity to the rotating grinding table, mixing with classifier rejects returned for re-grinding.Centrifugal action forces the coal outward to the grinding ring where it is pulverized between the ring and three grinding rollers.
Vertical coal mill also called coal grinder is the most used machine for coal grinding according to our mining experience. Raymond mill is also the early coal mill, the capacity of this coal mill can be up to 6-8 t/p.Ball grinding mill is the early coal mill used in coal powder plant, there are two types, wet ball mill and dry ball mill.
Concrete Plant For Sale,Used Mobile Concrete Crushing Plant Layout
Mobile concrete crushers introduction
As a top producer of entire set of crushing and screening plant gear along with a answer provider of aggregate production, The design concept for PP sequence portable crushing and screening plant is to totally meet the various specifications of cellular crushing function. This can provide a whole new operation mode that greatly decreases the operation cost.Direct function Integrative sequence transportable crusher can function independently.
For various customers requirements on material and crusher size, versatile process can meet the requirements of transportable crushing and screening, which may greatly decrease the price. Integrative whole set Integrative installation avoids the multifarious works for separate machine installation, and decreases material and time expenditure. Compact composition improves the on-site flexibility.Versatile configuration and great adaptability: Based on the various specifications of various crushing procedure, PP series transportable crushing and screening plants can form the subsequent two processesof crushing first, screening 2nd or screening first, crushing 2nd. The crushing plant can be composed of two-stage plants or three-stage plants. The two-stage plant is made up primary crushing plant and secondary crushing plant, while the three-stage plant consists of main crushing plant, center crushing plant andtertiary crushing plant, every of that is of higher flexibility and may be used individually.
Concrete processing consists of bursting and crushing process
Recycled aggregate concrete collected from demolition websites is put via a crushing machine. Crushing facilities accept only uncontaminated concrete, which must be free of trash, wood, paper along with other such supplies. Metals such as rebar are accepted, since they can be removed with magnets along with other sorting gadgets and melted down for recycling elsewhere. The remaining aggregate chunks are sorted by dimension. Bigger chunks may go through the crusher once more. Following crushing has taken place, other particulates are filtered out through a variety of techniques including hand-picking and h2o flotation.
Concrete Crushing Plant Layout
SBM is a manufacturer of crushing plant, and materials complete concrete crushing plant, concrete recycling equipment, building waste recycling machine, and main machine and spare components in concrete line. We can also design Mobile concrete crushing plant according to the operating condition or the customers's requirements.
SBM machinery, which is really a expert producer of concrete crushing equipment, offers concrete crushing gear, concrete crushing machine and concrete crushing plant for sale, employ, rental. When you have concrete need to be crushed or recycling, you are able to buy or employ our concrete crushing plant.
Crushed Manufactured Sand Concrete-Sand Plant
Sand Making Plant instruction
Artificial sand is widely used in highway construction, crusher plant layout, etc. As the field of industry application gradually expanded, the gradual application of natural sand failed to keep pace with the various sectors of modern world development needs. In this case, machine-made sand is produced to meet the great needs. There are many kinds of rocks that could beused to make sand, there are Granite, Natural river pebbles, Basalt, Limestone and so on.
Sand making plant consists of vibrating feeder, jaw crusher, vertical shaft impact crusher (sand making machine), vibrating screen, sand washing machine, belt conveyor and centrally electric controlling system, etc. The designed capacity is from 50t/h to 500t/h. After many years' research, our company has developed an internationally advanced vertical shaft impact crusher, which can be used together with other machinery as a complete sand making flow. This design racks a leading role in the same industry.
Artificial Sand Making Process:
The stone processing plant material is sent regularly by the vibrating feeder to the primary jaw crusher, then it is sent to the secondary jaw crusher to be crushed again. The crushed material then is sent by belt conveyor to vibrating screen to be separated. The suitable size can be sent to the sand making machine, while unsuitable material is sent back to the secondary jaw crusher to be crushed again. The crushed material from the sand making machine is sent back to the vibrating screen to be separated. The suitable separated sand, which is the final product, should be sent to the sand washing machine to be cleaned, and then sent by the belt conveyor. The unsuitable separated sand should be sent back to the sand making machine to be crushed again. We could design different capacity's sand production line according to your personal requests.
Crushed Manufactured Sand Concrete
Integrating three crushing types, VSI5X Sand Crusher becomes the core aggregate crushing equipment in sand making plant. It adopts Germanic advanced technique and owns a number of patents and independent intellectual property rights. VSI5x series crusher is highly recommended to crush high hardness materials as iron ore, nonferrous metals, corundum, and bauxite, quartz sand, basalt, etc. It is widely applied in industries like cement making, refractory making, glass raw materials making, aggregates making, sand making, metallurgical industry, etc. VSI sand crusher is the best sand crusher machine used in sand making plant.
Recycled Aggregate Concrete Crusher Machine,Aggregate Plant
Recycled Aggregate Concrete
Construction aggregate and building aggregate is widely used in most types of concrete production. And recycled aggregate concrete is one of the major sources to get construction aggregate and building aggregate. Crushed stone aggregate is produced from many natural deposits including: limestone, granite, trap rock along with other durable mineral resources. Aggregate production line manufactured by SBM Machinery aims for producing crushed stone aggregate. The aggregate process consists by progressive stages of crushing, screening, and washing.
The aggregate production flow chart
The blasted raw stones was hauled for the a stockpile by heavy duty truck, then the raw stones like granite, basalt, marble, limestone, cobble stone etc. will be fed into jaw crusher as primary crushing machine the crushed stones is going to be transferred to impact crusher or cone crusher for further processing. Based on the clients application, the crushed stone is going to be sieved into different grade by vibrating screen, or why not be transferred to cone crusher for fineness crushing.
After screening process, sand washer will probably be necessary to remove the dust and small particles. Then crushed stone aggregate is produced. One unit of SBM aggregate production line can produce approximately 1000 TPH, the grain size will be 0-5mm, 5-10 mm, 10-20mm, 20-40mm, 40-60mm and also larger.
Crushed stone aggregate can be used inside the construction of highways, railroads, airports, water and sewage systems, office buildings, factories and our homes.
Aggregate crushing equipment
SBM Machinery is a premier supplier of crushing and screening equipment, and related auxiliary equipment in China. We offer complete crushers and screens for producing all sorts of aggregate,we can also supply the complete turn-key aggregate production circuit.
General Equipme Supplies provides top quality construction and aggregate crushing equipment, supported by excellent repair facilities, field service capabilities, trained and certified technicians and a multimillion dollar parts inventory. Over 25 years of success comes from delivering reliable service through excellent product support and by offering the finest lines of construction machinery and aggregate processing gear available.
Complete stationary, portable, mobile aggregate crushing equipment are available. Our aggregate crusher machine with ISO and CE certificates have been sold to over 100 countries around the globe. Besides, we have established branch offices in several countries.We have different crushing plants, our professional staff will offer suitable solutions according to the needs you have.
Cement Production Process,Cement Industry Process-Cement Plant
Cement Manufacturing Process
1. The dry cement process consists of many simultaneous and continuous operations using some of the largest moving machinery in manufacturing. Over 5000 sensors and 50 computers allow the entire operation to be controlled by a single operator from a central control room.
2. The limestone is combined with clay, ground in a crusher and fed into the additive silos. Sand, iron and bottom ash are then combined with the limestone and clay in a carefully controlled mixture which is ground into a fine powder in a 2000 hp roller mill.
3. Next, the fine powder is heated as it passes through the Pre-Heater Tower into a large kiln, which is over half the length of a football field and 4.2 metres in diameter. In the kiln, the powder is heated to 1500 degrees Celsius. This creates a new product, called clinker, which resembles pellets about the size of marbles.
4. The clinker is combined with small amounts of gypsum production process, limestone and finely ground in a finishing mill. The mill is a large revolving cylinder containing 250 tonnes of steel balls that is driven by a 4000 hp motor. The finished cement is ground so fine that it can pass through a sieve that will hold water.
5. The cement mill process begins when limestone, the basic raw material used to make cement, is transported by rail to the Edmonton plant from the Cadomin limestone quarry 220 kilometres west of Edmonton.
Cement plant is usually located closely either to hot spots in the market or to areas with sufficient quantities of raw materials. The aim is to keep transportation costs low. Basic constituents for cement (limestone and clay) are taken from quarries in these areas.
Cement ball mill:
Cement ball mill is also named natural material mill, material grinding mill and clinker mill, is key equipment for grinding following the concrete crush process, which can be trusted in the manufacture industries, including cement, silicate, new building materials, refractory material, fertilizer, ferrous metal, nonferrous steel and glass ceramics, etc. Cement ball mill may be used for the dry and wet grinding for all kinds of ores as well as other grind-able materials. Based on different materials and discharging methods, there are dried up cement ball mills and wet ball mills for option.
Waste Recycling Plant,Recycling Plant
The present construction waste recycling already have some technical basis, regardless with the laboratory research or market applications have certain results. Shibang Mining Machinery self-developed hydraulic drive track-type mobile crusher plant and tire cellular crusher station, the construction rubbish coarse broken, the broken and broken bits, according to the various requirements of various clients to flexibly configure a crushing, crushing two and 3 grade crushing cellular crusher station gear, while whatsoever levels to optimize the combination of crushing and screening, we will do our best to meet customer requirements. With regard to mobile crusher station “broken after the very first screening” of “first screen following the broken” and detailed procedure.
Numerous with the waste of construction waste through sorting, eliminate, or crushed, the vast majority can be used as renewable sources, re-use like: scrap steel, scrap wire, scrap wire, and numerous equipment and other metal scrap, after sorting, focus, re-melted once more after the crushing processing and production into many different specs of steel; waste timber bamboo could be utilized to make synthetic wood; brick, stone, concrete along with other supplies through the crush, they can on behalf of the sand used in masonry mortar, plaster mortar, enjoying concrete cushion and so on, can also be utilized to produce creating blocks, paved street, brick, tiles along with other creating supplies lattice.
Construction Waster Recycling Equipment
SBM is a leading manufacturer of crushing and screening equipment in China, has rich experience in the fields of construction waste recycling, quarrying, minerals processing and so on. The crushing and grinding machine have been exported to many countries.
We adopt crushing and screening equipments to process construction waste into reutilized concrete aggregate, new wall raw material, road base auxiliary material and so on.
Generally, construction waste recycling plant often use two processing methods: mobile crushing plants and stationary crushing plants.The recycled construction waste can be processed into regenerated concrete aggregate, new wall raw material, road base auxiliary material and so on, which can achieve economic, social and ecological benefits of construction waste reclamation, reduction and harmlessness.
Gold Ore Mining,Gold Ore Mining Process Equipment
Gold Ore Mining Process
The easiest process used for mining gold is panning, employing a circular dish often having a small pocket at the bottom. The prospector fills the dish with gold-bearing sand or gravel, holds it within a gentle stream of water, and swirls it. The lighter areas of the gravel are gradually washed off as well as the gold particles are still nearby the center with the pan or even in the pocket.
To separate the gold in the gold ore collected in the mine tunnel, the ore was crushed with a series of gold ore crushers, for example primary jaw crusher found in preparing samples for assaying.
The first step of separate the gold from gold ore is crushing, then gold ore is crushed to be able to increase the surface area of the gold ore for greater gold recovery. Gold mining process equipment is loaded in to the primary crusher for initial sizing. The jaw crusher can break the gold ore rocks into 150mm or 6 inch, then belt conveyor will transport the crushed gold ore screening plant, which runs the gold ore through vibrating screens to size the fabric. Oversized rock is sent via conveyor to the secondary crushers. Secondary crushing includes impact crusher and cone crusher. inch diameter or smaller, lime is added to the ore to boost the effectiveness of the method solution by raising the PH. The gold ore is then conveyed for the load out bin. Trucks drive beneath the load out bin being filled with crushed ore for delivery towards the leach facility.
Gold Ore Beneficiation Plant:
Because of the nature of the various types of gold ore is different from methods used by different dressing, but the commonly used re-election, flotation, amalgamation, cyanidation, and the resin slurry method in recent years, CIP adsorption, the new heap leaching of gold mining tool and equipment. For certain types of ore, of gold is often a joint process.
Re-election in the rock gold mine used widely, more as a secondary process, in the autogenous mill to recover coarse gold, flotation and cyanidation process to create favorable conditions to improve the mineral index, increased the total recovery of gold on the increased production And reduce the cost to play a positive role. About Shandong Province, more than 10 with gold plant using the re-election this process, the average total recovery can be increased by 2% to 3%, good economic efficiency of enterprises, according to incomplete statistics, the annual profit of several million dollars available. Henan, Hunan, Inner Mongolia and other provinces also achieved good results, with the main chute equipment, shaker, jigger and short-cone cyclone and so on. Most of the gold mines from our view, floating - Re Joint processes for use in the future we should vigorously promote the stage grinding stage sorting process, this can be advocated, as early as the principle of closing the dressing.
Types of Coal Crusher for Sale Used Coal Crusher Plant
Coal crusher is a type crusher of ore crushing equipments used for coal plant. Coal crusher is acknowledged well in coal processing industry for a long time. It is used widely in coal mining and coal processing because of its advantages. Liming is a major coal crusher manufacturer and supplier for power plants, coke ovens or other related coal crushing company. As the largest exporter in the design and manufacture of coal crushers and spare parts, Liming coal crushers are used in a wide variety of material reduction and processing applications in 100 countries around the world.
Coal crusher classification
According to the coal processing plant, we divide coal crusher into three types as follows.
1. Primary coal crusher: Coal jaw crusher, coal impact crusher, coal Hammer Crusher (coal hammer mill)
Coal jaw crusher, is used for crushing and broking big or large coal in the first step of coal crushing plant applied most widely in coal grinding mill. With its unique advantages, coal Hammer Crusher is favor of our customers. Coal hammer crusher is developed from hammer crusher that is suitable for mid-hard and light erosive materials, whose pressure resistance strength is no more than 100Mpa and humidity lower than 15%, such as coal, salt, chalk, gypsum, blocks, limestone, etc.
2. Secondary coal crusher: Coal cone crusher
Coal cone crusher from Liming includes Symons cone crusher, hydraulic cone crusher, HCS cone crusher and so on. Besides this, with high-efficiency and hydraulic pressure, cone crusher designed by crusher manufacturer Liming was widely used in mining, concrete factory, sandstone making, etc.
3. Tertiary coal crusher: Coal mobile crusher, if you want to know more about this crusher, and then click coal mobile crusher.
Coal crusher used in coal crushing plant
In the coal crusher plant, coal crusher can resize the coal stone so that it can be easily handled and processed. Liming coal crusher is acknowledged in its field since long time and gives smooth running resulting power economy and higher efficiency. For the Mosh hardness of coal is usually under 5, the miners can use jaw crusher, JC jaw crusher, hammer crusher, impact crusher, and hydraulic impact crusher etc. to handle it. After the coal has been crushed by coal crusher, we need vibrating screen to grade the coal by size and then transport the coal via belt conveyor. In this process, dewatering screen is optional to remove water from the product. More about working details about coal crushing plant.
Coal Preparation plant generally use gravity process equipment to separate the refuse from the product (coal). Coal has a specific gravity between 1.35 and 1.5, while the refuse rock has a Specific Gravity of 2.1 to 2.3. Heavy Media is the most popular method of cleaning coarse sizes, jig plants are probably the second most common method used for coarse coal. Heavy media cyclones are being used more often for fines size fractions. Flotation is generally used to clean the -28 mesh size fraction, although spirals and heavy media cyclones have shown success in cleaning down to 100 mesh coal feed. Spirals are generally used for middling sizes ( 10 mesh to 60 mesh).
Coal Processing Description
As it leaves the mine, coal varies widely in size, ash content, moisture content, and sulfur content. These are the characteristics that can be controlled by preparation. Sizes range upward to that of foreign materials, such as a chunk of rock that has fallen from the mine roof or a metal tie;large pieces of coal from a very hard seam are sometimes included. Ash content ranges from three to sixty percent at different mines. Most of the ash is introduced for the roof or bottom of the mine or from partings (small seams of slate) in the coal seam. This ash, called extraneous ash, is heavier than 1.80 specific gravity. The remaining ash is inherent in the coal crushing plant. The density of coal increases with the amount of ash present. The moisture content of the coal is also of two types. The surface moisture, that which was introduced after the coal was broken loose from the seam, is the easier to remove. This moisture is introduced by exposure to air, wet mining conditions, rainfall (in stockpiles), and water sprays. The remaining moisture, called “bed”, “cellular”, or “inherent” moisture, can be removed only by coking or combustion. This moisture was included during formation of the coal.
Coal Processing Equipment and Machines
Coal preparation serves several purposes. One important purpose is to increase the heating value of the coal by mechanical removal of impurities. This is often required in order to find a market for the product. Run-of-mine coal from a modern mine may incorporate as much as 60 percent reject materials.
Air pollution control often requires partial removal of pyrites with the ash to reduce the sulfur content of the coal. Ash content often must be controlled to conform to a prescribed quality stipulated in contractual agreements. Because of firing characteristics, it is often as important to retain the ash content at a given level as it is to reduce it.
Freight savings are substantial when impurities are removed prior to loading. Finally, the rejected impurities are more easily disposed of at the mine site remote from cities than at the burning site, which is usually in a populated area.
Coal Vibrating Screen, Screen For Coal Preparation
We have a wide range of Vibrating screens suitable for various screening application. The Coal Vibrating Screens are used to separate materials into various sizes for further processing in Crusher. Coal conveyor belt works on circular motion. It is applicable for wide range of operations like screening of dry or wet sand gravel crushed stone, mineral ores and industrial applications. We offer screens in a variety of combination of sizes to apt solutions for different capacity requirement for coal crusher. In screen grading, the material is separated mechanically on screen plates. Vibrating screen has rolling bearing stressed by high loads. Output of the screen depends on screen inclination, feeding system, screen RPM and vibration ratio. We can design and supply all ranges of vibrating screens according to the capacity and requirement.
Vibrating screen manufacturer is for stand alone or supplemental installations. It can be manufactured in customized shape and size fit to the crusher and other processing applications and production requirements. Vibro screens are suitable with various screening systems. It can be installed and integrated with existing crusher units and plants. Screens are used for discharging bulky goods, sand, gravel, coal, mineral ores and coke from hoppers to crusher.
Coal Screening Plant Features:
1. It uses eccentric block to produce strong exciting force.
2. Crossbeam and the main body of the screen are connected with high strength screw bolts. So they have the features of simple structure and easy maintenance.
3. It adopts tire coupling with capability of flexible connection and stable operation.
4. It adopts the structure of small amplitude, high frequency, large obliquity to make the screen hold the capability of high efficiency, large handling capacity, long life span, low consumption, little noise.
Types of surface mining and open-cut mining
1. Dredging
This is a high-volume mining technique for low-value products near a plentiful source of water. Scoops/buckets are used to extract material from shallow water (often man-made lagoons). A high-tech variation of this is undersea mining, where material is sucked from the seafloor (although the only successful application of this to-date has been for gem diamonds in shallow waters).
The mining process is usually combined with the processing (typically drying and concentration) on a floating barge, which is anchored in the middle of the lagoon.
2. Surface Mining
Called 'Open-cast' if soft-rock mining (eg coal mining process or limestone) and 'Open-pit' if hard- rock mining (eg copper and diamonds). The mining process is fundamentally different between these soft- and hard-rock operations. The former operations are usually rectangular in general shape (and advance along the seam, with waste infill behind as they advance) while the latter are oval.
Surface mines normally only extend to a depth of about 200 m, below which it is usually cheaper to extract the metal from underground. The cut-off point will depend on the economies of the two methods, with surface costs being dominated by the ore:waste (stripping) ratio, which, in turn, will depend on the shape of the orebody, the amount of overburden to be removed and the safe steepness of the wall (ie bench height v width). This latter item will depend on the type of rock and the number of fractures etc.
Hard-rock surface mining is dominated by drilling/blasting and then lifting of the broken ore either into trucks or onto conveyors for transportation to the processing plant. This lifting is usually by excavator (electric or hydraulic; with shovel or backhoe configuration) or front-end loader. The softer rocks can be recovered directly by using very powerful excavators (including the huge bucket-wheel machines).
3. Types of Coal Underground Mining
Access is via vertical shafts or inclined roadways (adits). There are usually two access routes (one for men and materials, and one for the ore) for safety and for ease of ventilation (fresh air comes in one and is then exhausted out of the other).
Once at the correct depth, horizontal tunnels are driven to reach the ore deposit. These are permanent structures so require strong roof supports (often including 'bolts' into the rock to tie the layers together for strength). In contrast, tunnels into the ore deposit itself are often temporary, and so the support is less substantial. Transport for men and materials can be by train, truck or man-riding conveyor belts.
4. Insitu Mining
Solution - Involves the injection of water down drill holes into soluble deposits (most commonly salt). The mineral-rich solution is then pumped back to the types of mining of surface.
Thermal - Although only still at the research stage, it is theoretically possible to burn coal insitu (by creating cracks, then injecting oxygen and a heat source) and recovering the resultant heat (in effect, an underground power station without going to the trouble of extracting the coal). This has happened spontaneously in numerous areas (particularly in India) but the difficulty has always come in controlling the burning process.