COPPER GOLD INDUSTRY INFORMATION

The overall development of the copper mining industry is directly linked to some factors like electricity and transportation. Beside these two factors, some other significant elements directly or indirectly linked behind the growth of copper mining industry are miners (mineworkers), machineries, and surrounding environments.


Copper ore grades

From the start of copper mining, ore has been divided into two classes. The rock with higher copper content was smelter ore, also called direct shipping ore, and required no treatment before going to the smelter. The rock with less copper was called milling ore, or concentrating ore, and required crushing and separation of ore minerals from the waste rock to produce copper concentrate, which was sent to the smelter.


Use of copper

Some practical applications of copper include the use of copper in construction, electronic and electrical industries. Examples are electrical and heating appliances, tubes, telecommunications, refrigeration, pipes, and other household appliances.

The copper industry’s growth and prosperity are based on the metal’s inherent properties: an attractive appearance, high conductivity, good corrosion resistance, ability to alloy with other metals, and ease of working. While there are substitutes in specific uses, copper has entrenched and expanding markets in the electrical, electronic, and communications industries. Electrical and electronic products, including power cables, account for over one third of total usage, and construction, including wiring and water tubing, for a similar share. Transport industries use roughly one eighth of the total, industrial machinery and equipment nearly one tenth, and a wide range of consumer and other products the remainder.


Gold Mining Industry

Gold Mining Industry Photo

Gold mining is a global business with operations on every continent, except Antarctica, and mines of widely varying types and scale. The vast majority of the world’s gold was mined in the modern, post-war era and as the industry has evolved it has also diversified.

Each year, approximately 2500 tons of gold are mined throughout the world. South Africa leads the world in gold mining, and the U.S., Russia, Canada, and Australia are also major producers. Gold is distributed widely over the earth, and gold mining is pursued in most countries with some success.

Located in South Africa, the Witwatersrand Basin represents the richest gold field ever discovered. It is estimated the 40% of all of the gold ever mined has come out of the Basin. In 1970, South Africa’s output accounted for 79% of the world’s gold production.

The largest producing gold mine in the world, the Grasberg mine in Papua, Indonesia, is primarily a copper mine. Gold ore processing in placer mines, the gold is recovered by gravity separation. For hard rock mining, other methods are usually used.


Hard rock gold mining

Hard rock gold mining extracts gold encased in rock, rather than fragments in loose sediment, and produces most of the world’s gold. Sometimes open-pit mining is used, such as at the Fort Knox Mine in central Alaska. Barrick Gold Corporation has one of the largest open-pit gold mines in North America located on its Goldstrike mine property in northeastern Nevada. Other gold mines use underground mining, where the ore is extracted through tunnels or shafts. South Africa has the world’s deepest hard rock gold mine up to 3,900 metres (12,800 ft) underground. At such depths, the heat is unbearable for humans, and air conditioning is required for the safety of the workers. The first such mine to receive air conditioning was Robinson Deep, at that time the deepest mine in the world for any mineral.


By-product gold mining

Gold is also produced by mining in which it is not the principal product. Large copper mines, such as the Bingham Canyon mine in Utah, often recover considerable amounts of gold and other metals along with copper. Some sand and gravel pits, such as those around Denver, Colorado, may recover small amounts of gold in their washing operations. The largest producing gold mine in the world, the Grasberg mine in Papua, Indonesia, is primarily a copper mine.

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Gold & Copper mine access

Underground access

Declines are often started from the side of the high wall of an open cut mine when the ore body is of a payable grade sufficient to support an underground mining operation but the strip ratio has become too great to support open cast extraction methods. They are also often built and maintained as an emergency safety access from the underground workings and a means of moving large equipment to the workings.

Accessing underground ore can be achieved via a decline (ramp), inclined vertical shaft or adit.

  • Declines can be a spiral tunnel which circles either the flank of the deposit or circles around the deposit. The decline begins with a box cut, which is the portal to the surface. Depending on the amount of overburden and quality of bedrock, a galvanized steel culvert may be required for safety purposes. They may also be started into the wall of an open cut mine.
  • Shafts are vertical excavations sunk adjacent to an ore body. Shafts are sunk for ore bodies where haulage to surface via truck is not economical. Shaft haulage is more economical than truck haulage at depth, and a mine may have both a decline and a ramp.
  • Adits are horizontal excavations into the side of a hill or mountain. They are used for horizontal or near-horizontal ore bodies where there is no need for a ramp or shaft.

Selective mining methods
  • Cut and fill mining is a method of short-hole mining used in steeply dipping or irregular ore zones, in particular where the hanging wall limits the use of long-hole methods. The ore is mined in horizontal or slightly inclined slices, and then filled with waste rock, sand or tailings. Either fill option may be consolidated with concrete, or left unconsolidated. Cut and fill mining is an expensive but selective method, with low ore loss and dilution.[4]
    • Drift and fill is similar to cut and fill, except it is used in ore zones which are wider than the method of drifting will allow to be mined. In this case the first drift is developed in the ore, and is backfilled using consolidated fill. The second drift is driven adjacent to the first drift. This carries on until the ore zone is mined out to its full width, at which time the second cut is started atop of the first cut.
  • Shrinkage stoping is a short-hole mining method which is suitable for steeply dipping orebodies. The method is similar to cut and fill mining with the exception that after being blasted, broken ore is left in the stope where it is used to support the surrounding rock and as a platform from which to work. Only enough ore is removed from the stope to allow for drilling and blasting the next slice. The stope is emptied when all of the ore has been blasted. Although it is very selective and allows for low dilution, since most of the ore stays in the stope until mining is completed there is a delayed return on capital investments.
  • Room and pillar mining: Room and pillar mining is commonly done in flat or gently dipping bedded ore bodies. Pillars are left in place in a regular pattern while the rooms are mined out. In many room and pillar mines, the pillars are taken out starting at the farthest point from the stope access, allowing the roof to collapse and fill in the stope. This allows for greater recovery as less ore is left behind in pillars.
  • VRM: Vertical retrieval mining is a method where mine is decided in vertical zones with depth of about 50 meters. Long-hole high diamond drilling is done through ITH drills. Material retrieval is done from bottom of the section developed. Ore blasted in retrieval taken in phase. Last cleaning of ore is done through remote controlled LHD machines. The zone is now back filled using cemented mix fill. Side chambers will be mined in pre-planned sequence after the fill has solidified.

Bulk mining methods

Block caving is used to mine massive steeply dipping orebodies (typically low grade) with high friability. An undercut with haulage access is driven under the orebody, with “drawbells” excavated between the top of the haulage level and the bottom of the undercut. The drawbells serve as a place for caving rock to fall into. The orebody is drilled and blasted above the undercut, and the ore is removed via the haulage access. Due to the friability of the orebody the ore above the first blast caves and falls into the drawbells. As ore is removed from the drawbells the orebody caves in, providing a steady stream of ore. If caving stops and removal of ore from the drawbells continues, a large void may form, resulting in the potential for a sudden and massive collapse and potentially catastrophic windblast throughout the mine. Where caving does continue, the ground surface may collapse into a surface depression such as those at the Climax and Henderson molybdenum mines in Colorado. Such a configuration is one of several to which miners apply the term “glory hole”.

Orebodies that do not cave readily are sometimes preconditioned by hydraulic fracturing, blasting, or by a combination of both. Hydraulic fracturing has been applied to preconditioning strong roof rock over coal longwall panels, and to inducing caving in both coal and hard rock mines.


Ore removal

In mines which use rubber tired equipment for coarse ore removal, the ore (or “muck”) is removed from the stope (referred to as “mucked out” or “bogged”) using center articulated vehicles (referred to as boggers or LHD (Load, Haul, Dump machine). These pieces of equipment may operate using diesel engines or electric motors, and resemble a low-profile front end loader. LHD operated through electricity utilize trailing cables which are flexible and can be extended or retracted on a reel.

Solutions Case Studies

ASGCO® Tru-Trainer® Dual Return Urethane Idlers Save the Day at this Copper Mine.

Objective: To track and align the conveyor belt on the return side of the belt before the loop take-up section, while leaving the 6 series deflector pulley system with double speed reducers. Challenge: The challenge involved an extreme incline conveyor…

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Objective: To track and align the conveyor belt on the return side of the belt before the loop
take-up section, while leaving the 6 series deflector pulley system with double speed reducers.

Challenge: The challenge involved an extreme incline conveyor belt 96” wide, with tandem
drives and a 6 pulley take-up system.  Due to the nature of this Drive system design, along
with the speed of the belt and together with the high tonnage that this system see’s during
each shift, severe belt mis-alignment was a serious problem. The conveyor belt had
tracking problems on the return side of the conveyor, especially through the 6 pulley
take-up system. This was exaggerated because of the incline and belt speed of this system.

luke-tt-dual-return-urethane_96_before-after_web

Solution: ASGCO® recommended that two Tru-Trainer®  Dual Return Urethane Idlers (96”)
be installed before and after the counter weight systems, while leaving the 6 series deflector pulleys
in the loop take-up system. The current trainer was an 84” modified unit brought over from
another conveyor system. The Tru-Trainer®  Dual Return Urethane Idlers being installed would
simplify the installation process and improve the tracking conditions in that section. This would
center the belt before those critical areas, avoiding the possible loss of material due to belt
mis-tracking on this long high speed, high tonnage conveyor belt system. 

Results: The damages to the belt since the installation of the Tru-Trainer®  Dual Return
Urethane Idlers have been completely eliminated. There was also a significant improvement
in the overall production average for the month following the installation. Due to the
excellent performance of the Tru-Trainer® Dual Return Urethane Idlers, the customer is
purchasing several additional units as a new preventative maintenance implementation.

Tru-Trainer® Dual Return Urethane Idler

luke-tt-dual-return-urethane_96_web

  • Designed for High Speed/PIW Conveyors
  • Accommodates Excessive Force
  • Enhanced Sealing/Bearing System
  • Heavy Duty Rolls – 5/8” Polyurethane Lagged
  • Central Pivot with Two Individual Rollers
  • Total Satisfaction Guarantee (TSG)
  • Excellent for Reversing Belt Applications
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ASGCO® Tru-Trainer® Tapered Troughing System Eliminates Belt Tracking Issues at This South American Copper Mine.

Objective: To prevent belt tracking issues before the critical curved areas of the belt, causing belt damage. Challenge: The challenge was to track a horizontally curved, overland primary crusher belt before it gets to a critical mis-tracking stage and eventually damages…

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Objective: To prevent belt tracking issues before the critical curved areas of the belt,
causing belt damage.

Challenge: The challenge was to track a horizontally curved, overland primary
crusher belt before it gets to a critical mis-tracking stage and eventually damages
the belting system. This would be an exceptionally difficult challenge due to the
harsh environmental conditions of the operation. They had been using conventional
guide roller trackers which continually failed, causing belt damage.

Case Study_TT Before and After_web

Solution: ASGCO® recommended a series of Tru-Trainer® Tapered Troughing Idlers
be installed before the curved section of the belt. This would center the belt before those
critical areas, avoiding the possible loss of material due to belt mis-tracking on these
high speed and high tonnage loads on the overland crusher belts.

Results: This new generation of Tru-Trainer® Tapered Troughing Idlers is very easy
to install thanks to its’ unique design concept. As the taper wing rollers are inline, it
operates on both on Uni-directional or Bi-directional conveyor belts. The tracking is
done by the tapered wing rollers which are lagged and can be easily adjusted between
25°- 55°. The tapered wing rollers ensure that the idler activates immediately as the belt
moves off center. ASGCO®’s Tru-Trainer® Tapered Troughing Idler’s superior belt tracking
performance is saving the mine money due to less spillage, less downtime and less belt
wear. The customer was ecstatic with the number of units correctly installed in the minimal
allowable time for their maintenance window.

  • Exceptional Performance – The combination of the tapers Case Study TT 1_web
    and unique center pivot, provide fast, reactive and
    continual tracking in all conditions
  • Individual rollers for easy replacement – Both the taper
    and center roller can be individually replaced as wear occurs.
  • Enhanced Center Pivot – The unique heavy duty pivot
    design provides instant activation to centralize the belt
    to keep it running center.
  • Maintenance Free – Bearings do not require any greasing
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ASGCO® Dura-Sleeve® V-Return Idlers Solve Belt Tracking Problems at This High Tonnage South American Copper Mine.

Objective: Provide reliable rollers, better alternative to inadequate rollers that fail consistently. Challenge: The demanding conditions of heavy tonnage and high speeds would wear out the previous metal rollers too quickly. The high speed of 23 ft per second per second…

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Objective: Provide reliable rollers, better alternative to inadequate rollers that fail consistently.

Challenge: The demanding conditions of heavy tonnage and high speeds would wear out the
previous metal rollers too quickly. The high speed of 23 ft per second per second (7 meters)
and a tonnage capacity of 8000 tons per hour, caused the rollers to fail and fall apart, mainly
due to the rubber ring design. Specifically the problem was the high belt speeds that would
spin the rubber discs on the old rollers resulting in failure. Also the uneven wear was causing
the rollers to spin unevenly and then to overheat the rollers causing failures. The quality
required for this application needed to be extremely durable and wear resistant.

Recommendations: We recommended the Dura-Sleeve® idlers with patented replacement
sleeves for extra long wear. The compound provides higher wearability than the standard rubber
discs in abrasive environments and with little or no build-up.

Dura Sleeve_Before and After

Results: The customer was experimenting with different rollers because of the demanding conditions,
The introduction and installation of the ASGCO® Dura-Sleeve® V-Return Idler proved to
be extremely reliable.

ASGCO® Dura-Sleeve Return IdlersNew-Smooth-Dura-Sleeve

Patented Design – of our idler sleeve clamping system
utilizes you to replace worn out rubber or other urethane
disc return idlers.

Abrasion Resistant Urethane – compounds provide wear
ability that exceeds 5 times the wear life of standard rubber
disc return idlers.

Meets all CEMA Standards – and available in any
conveyor belt width and inside and outside roller diameter.

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ASGCO® – Troughing Tru-Trainer® Conveyor Belt Tracking System Solves Belt Tracking Problems at this Copper Mill Process Facility

This copper mill facility was processing crushed ore the consistency of sand. They were using conventional guide roller trackers that kept failing. Due to the design of the guide rollers they continually came in contact with the belt’s edge which…

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This copper mill facility was processing crushed ore the consistency of sand. They were using conventional guide roller trackers that kept failing. Due to the design of the guide rollers they continually came in contact with the belt’s edge which made them slow to react and caused premature “side wear” on the belt. The operators were prone to “tying the guide rolls off” which eliminated “the ability for it to train/align the belt”. Also “build-up” of carry-back on the external pivot caused freeze-up (stop working) making it vulnerable to the elements of the harsh environment.

Troughing-Tru-Trainer-at-Copper-Mill-Processing-Facility

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ASGCO – Fourthane Provides Solution for Repairs of Conveyor Belt Covers and Mechanical Fasteners

ASGCO Fourthane®. A new synthetic rubber with high tear and impact resistance, is formulated to be applied on conveyor systems that operate under high impact and abrasion conditions, resulting in less downtime. (more…)

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ASGCO Fourthane®. A new synthetic rubber with high tear and impact resistance, is formulated to be applied on conveyor systems that operate under high impact and abrasion conditions, resulting in less downtime.

ASGCO-Fourthane-Case-Study

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ASGCO Return Roll Changers Provide Safety for Conveyor Maintenance Crews

At this copper mining operation, the return idlers that track the belt on the conveyor system were very hard to access. The only way to change the idlers on this 36” wide conveyor belt, was to clear out all of…

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At this copper mining operation, the return idlers that track the belt on the conveyor system were very hard to access. The only way to change the idlers on this 36” wide conveyor belt, was to clear out all of the material on the ground and rent a 135’ man lift to access the conveyor belt tracking return idlers.

ASGCO-return-roll-changer-casestudy

ASGCO-return-roll-changer-casestudy results

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Copper Mine Solves High Wear Areas with Armorite™ Conveyor Wear Liners

A copper mine was experiencing high wear in their “pant-leg” chute liners. A combination of abrasive material and high tonnages was the major factor why the mine was only about to get 4-5 weeks from 1” thick AR500 plates. (more…)

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A copper mine was experiencing high wear in their “pant-leg” chute liners. A combination of abrasive material and high tonnages was the major factor why the mine was only about to get 4-5 weeks from 1” thick AR500 plates.

Armorite-Copper-Mine

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