Gold Processing Newmont At Batu Hijau Mine

Gold mine Batu Hijau is  located on the Sumbawa island  in the province of West Nusa Tenggara,  Indonesian country

Gold processing in the Batu Hijau mine, through several process stages. Ranging from drilling and blasting rock mineral, up to hauling rock material into the processing plant area

Gold mine Batu Hijau is  located on the Sumbawa island  in the province of West Nusa Tenggara,  Indonesian country.  The mine is the result of a ten-year exploration and construction program based on a 1999 discovery of the porphyry copper deposit. Production began in 2000.

The Batu Hijau mine is an open pit copper-gold mine operated and the project is held  by Newmont Mining Corporation's subsidiary company PT Newmont Nusa Tenggara (PT Newmont), a company owned by Newmont Indonesia (US, 35.44%); Nusa Tenggara Mining Corporation (Japan, 27.56%), PT Pukuafu Indah (Indonesia, 20%) and PT Multi Daerah Bersaing (Indonesia, 17%).

Mineral Deposit In Batu Hijau Mine

How Process Smelting Gold

Smelting gold, silver, platinum and other metals at home is a popular trend these days, whereas it used to be of interest only to jewelry designers and artists.

Gold is purified by means of a smelting process, which utilizes pressure, high heat and chemicals to accomplish the task. Like any metal that appears naturally in the earth, there are impurities that must be removed. Removing minerals and other impurities allows gold to be used in its purest form

Have you recently scored some gold dust or small nuggets on a recent creek panning adventure?

Whether you are smelting natural gold you've recovered from prospecting, or the broken jewelry or beat up coins you no longer want, smelted gold is most easily sold or re-fashioned after first removing impurities and casting it into ingots.

Interested in The processes of smelting or roasting your ore to recover its gold and silver? Some fairly rich ores require a lot of work to get all the gold and silver out them.

Exploration Project Drilling For Gold Kerr-Sulphurets-Mitchell mining

A KSM drill rig perches above a deep valley about 80 miles east of Wrangell. (Photo by Ed Schoenfeld/CoastAlaska News)
A KSM drill rig perches above a deep valley about 80 miles east of Wrangell. (Photo by Ed Schoenfeld/CoastAlaska News)
British Columbia’s Kerr-Sulphurets-Mitchell mining project wrapped up its 2015 exploration season in late September. The KSM, about 30 miles east of the Alaska border, is the largest of 10 or so such projects near waterways that flow into Southeast. 

Its owner, Toronto-based Seabridge Gold, The Kerr-Sulphurets-Mitchell (KSM) mine, owned by Seabridge Gold, is located approximately 65km north-west of Stewart in British Columbia, Canada. It is one of the world's biggest gold / copper projects under development has already spent close to $200 million searching for ore. We take you there, during the previous season, to learn about the exploration process.

A drill rig grinds into the bedrock of a high ridge, overlooking a wilderness of snow-capped mountains and lushly vegetated valleys. The bright blue rig juts up through the roof of a rough shack of sturdy tarps, sheets of plywood and heavy timber.

Inside, Jeff Skinner is setting up the diesel-powered, hydraulic drill rig for its next run.

“Well, we’re doing mineral exploration for these gentlemen. We’re drilling the hole, pulling the rock samples out of the ground and sending them down to the geologists and they take care of it from there,” he says.

A glacier reflects in a naturally occurring pool of rusty, acidic water at the site of one of the KSM  prospect’s planned open-pit mines. (Photo by Ed Schoenfeld/ CoastAlaska News).

Long, brownish pipes are lined up outside the shack, waiting to be used.

“They put the steel in a giant drill chuck like you’d have in a hand drill. And turn it at high speed with a diamond bit at the end,” says Bill Threlkeld, senior vice president for exploration for Seabridge Gold, which has drilled 383 holes at the KSM over the past 10 years.

The pipes are sent deep into the ground and an inner sleeve brings back cylindrical samples, called cores. Threlkeld says they help pinpoint the location of the richest gold and copper deposits.

“It was at roughly 700 meters depth, so 2,100 feet, more or less, down. Before the work on this hole is done, the drill will reach more than two-thirds of a mile into the Earth,” he says.
“We have Mitchell 0-6, so it’s Mitchell, drilled in 2006, zero-one, first hole,” he says.

He’s taken me to near the end of a valley that can only be described as “raw.” It’s bare rock, with no trees or bushes.

At the valley’s upper end is what’s left of the glacier that once filled this U-shaped valley. Murphy says “once” wasn’t that long ago.

“We’re walking to an area where six years ago, where we’re standing, the ice would have been 10 feet above our outstretched arms. So you can see how much it’s receded,” he says.

The valley is splotched and streaked with rust, reddish-brown streams flowing down its sides. The color comes from exposed iron, which reacts with air and water.

Sulphurets Creek, which drains naturally occurring rusty water from the KSM prospect, enters the Unuk River. (Photo by Ed Schoenfeld/CoastAlaska News)
Sulphurets Creek, which drains naturally occurring rusty water from the KSM prospect, enters the Unuk River. (Photo by Ed Schoenfeld/CoastAlaska News)
“This is oxidation. Natural oxidation. And this is what produces the acid, which everyone has concerns about for water contamination,” he says.

Acidic water from mines and stored waste rock can hurt or kill fish, including those Alaskans depend on for food and jobs. KSM developers say it will be treated and stored properly at the site, about 80 miles east of Wrangell. Critics in Southeast cast strong doubts.

Up one side of the valley is a much different color. It looks like someone spilled a very large can of paint while ascending the ridge.

The blueish-green is just an indication that there’s copper in the system here. It gets exposed to the atmosphere and the copper comes out of solution. It’s an indication we’re in a mineral-rich area.

Because in this part of the world, where you find copper, you find gold.

After the cores are drilled out of the bedrock, they’re flown by helicopter to the KSM’s analysis operation, farther down the valley.

They’re cut into clearly labeled pieces for examination.Inside another wood-and-tarp building, Michelle Campbell points to the computer screen of what’s called a hyperspectral imaging device.

“A regular camera just looks at three spectral bands. But this one looks at 214 different spectral bands, so it’s much more precise,” she says.

The picture is electronically enhanced to show what’s on the surface of the rock core. She’s happy with what she sees, the presence of valuable metals.

“So in this one it would be like the reds and some of these darker, like brownie, colors. [They’re] the good stuff,” she says.

The cores and the enhanced images undergo further scrutiny before being shipped south for more detailed analysis by an independent lab. Those results determine whether and where the company will mine.
But other factors come into play. Seabridge Gold has the main provincial and federal permits needed to turn its exploration project into a mine. But it’ll still need to raise more than $5 billion, U.S., from potential investors.

Rock cores wait for analysis at the Kerr-Sulphurets-Mitchell project, one of the British Columbia mines planned for near the Southeast Alaska border. (Photo by Ed Schoenfeld, CoastAlaska News)

Source : News Gold Mining In The World

High Grade Gold Vein In Fire Creek Gold Mine Nevada

Gold nuggets in mines are not just a thing of the past. Fire Creek gold mine is one of the few mines in the world that can boast visible gold ore. The Fire Creek property is located in north central Nevada
The underground mine is in Lander County and is about seven miles northwest of Crescent Valley. The mine is owned by Klondex Mines Ltd.

Klondex acquired the Fire Creek property in 1975. From that time until 1999, Klondex had leased the property to four different companies, said Fire Creek Mine Manager Mike Isaak. Those companies did various stages of exploration. One of the companies even did a production heap leach test, but that didn’t prove out very well due to the nugget effect of the ore, Isaak said.

Klondex didn’t become “serious” about the property until 2004, he said.
“Over a short period of time they drilled 360,000 feet of drilling, which was all done from the surface at that time,” Isaak said.

The Fire Creek underground project was started in April 2011. Prior to that, people thought the mine would be a surface mine, but a change in leadership at the company was a turning point for how the mine was conceived, Isaak said.
“Paul Huet became CEO in September of 2012,” he said. “That was really a turning point for Klondex and for Fire Creek.”
In March 2014, Klondex announced the mine had 717,000 ounces of measured and indicated resources available.
“That started to get some people really excited about what’s the potential of Fire Creek,” Isaak said.
After that, the property’s next milestone was a gold pour, which was made possible when Klondex bought the Midas Mine in Elko County from Newmont Mining Corp.
“All the material that we produce is processed at Midas,” Isaak said.

Production Fire Creek gold mine Nevada

Joyce, Vonnie and Karen are the “premier veins” in Fire Creek, Isaak said. These veins are the main sources for the ore. The site plans on mining about 76,000 ounces of gold this year, he said.
The fourth vein is Hui Wu, said Fire Creek Chief Geologist John Marma.
“They’re all banded high-grade veins, the result of an epithermal vein system,” he said. “The grades speak for themselves.”

The Joyce Vein is 5.481 ounces per ton over 1.7 feet and the diluted grade is 1.422 opt over slightly more than 7 feet at particular faces, Marma said. He also went through select faces of the other veins: Vonnie is 1 foot of 80.056 opt and the diluted grade is 25.213 opt over slightly more than three feet. Karen is 2.5 feet at 8.324 opt and the diluted grade is 3.299 opt over 6.4 feet. The Hui Wu Vein is 5 opt over 1 foot.
Marma said the mine has “bonanza grades” because it is an epithermal system.
“It’s very typical of these systems,” he said. “With those bonanza grades we have seen upwards of 800 to 900 ounces per ton in some faces. … It’s a really well developed deposit and we expect to be here for awhile.”
An epithermal system is normally narrow, high grade and typically underground, he said. To mine the ore, they need to mill it. When asked to describe the type of ore in the mine, Marma said none of the ore is refractory or oxide. He said 60 percent is done on the course portion of the mill, because it still is found in nugget or visible form.
Part of the reason visible gold is found at Fire Creek is because the site wasn’t touched in the 1800s, Marma said.
“We’re mining high volume at quality tons,” he said.
The mine and the veins are open in all directions, Marma said. For example, the Joyce Vein has been mined for a quarter mile, but the end has not been reached yet.
“The property is grossly under-explored,” Marma said. “Only 2 to 3 percent has been mapped. The mineralization goes all the way to the surface but we haven’t found the end yet.”
Fire Creek is the highest grade gold producer in the world. According to, Fire Creek’s average grade is 1.5 ounces per ton. The next closest underground operation is Macassa Mine in Canada and it has an average grade of 0.77 opt. Turquoise Ridge Joint Venture, owned by Barrick Gold Corp. and Newmont Mining Corp., has the most reserves in tons for an underground gold mine, but its average grade is 0.59 opt.

The diluted grades for the Karen Vein ranged from 1 opt to 5 opt, Marma said.
“It was kind of a surprise,” he said. “She’s been a good vein.”
The veins consist of quartz, calcite and gold and silver. The host rock of the veins is basalt. Marma said the basalt holds a fracture open well and is a competent rock host. This means the mine needs very little shotcrete.
All of the ore at Fire Creek has been mined through cut-and-fill method, Isaak said.
“We’re transitioning to long-hole mining or open stoping,” he said.
The miners use jackleg and mechanized drills. The development mining is done with a mechanized drill and a lot of the vein mining is done with jackleg drills.
“We’re pretty excited about the transition,” Isaak said about changing to open stoping. “It will help lower costs. We won’t be able to do it everywhere, but where we can, we will.”

Employees Fire Creek gold mine Nevada

The staff as Fire Creek is mostly veterans of the mining industry.
Isaak came to Fire Creek in June 2014. He has 40 years of mining experience and has worked in underground mines all over the world throughout his career.
Marma has 17 years of underground and surface geology experience. He was hired by Klondex in January 2014. He worked previously for Newmont at the Midas Mine.
Doug Crawford has worked in the mining industry for 34 years. He has worked mostly underground and was hired to work at Fire Creek in December 2013.
Rob Crommelin is the senior safety manager and has worked in the industry for 14 years. Ten of those have been spent underground.
Fanuel Banda has 11 years of experience and most of that has been spent underground. He has worked in the U.S. and in Zambia.
Mike Baum has been in the mining industry for 22 years.

“We’ve pulled together quite a talent pool,” Isaak said. “Of the people that we just introduced, we have 135 years of mining experience here at this site. That’s very comforting for myself, as a mine manager, to know that we have that level of experience here, and we truly have people that are passionate about safety and making this property very successful.”
The site has 42 hourly and 21 salaried employees. Klondex started mining the site with a contractor, but took over operations in the early part of 2014. The company also has offices in Reno, Winnemucca and Elko. The property does have about 31 contractors who perform drilling, maintenance and security. The drilling on the surface and underground is done by American Drilling.
“It puts us just under 100 people on a regular basis,” Isaak said.
He said all the employees are proud of the site’s safety record. Last year it was awarded the safest small underground mine in the state for 2013.
“On the heels of that, in October of last year, Fire Creek had achieved two years of lost time free,” Isaak said. “We are currently at over a thousand days and will be celebrating three years of lost time free in October again this year. … In the mining industry that’s not easy to accomplish.”

Gold Mining Methods And Gold Processing In Kanowna Belle Gold Mine

The deposit Kanowna Belle gold mines  lies within the archaean Norseman-Wiluna greenstone belt and consists of a series of stacked lenses that have been identified over a strike length of 600m and to a depth of over 1,000m. The Kanowna Belle Gold Mine is a gold mines located 19 km north east of Kalgoorlie, Western Australia, near the ghost town of Kanowna. In mid-1999, Delta Gold bought North’s 50% share for AUS$90m, and became the sole owner. Delta subsequently merged with fellow Australian company, Goldfields Ltd, to form AurionGold, which in turn was bought by Canada's Placer Dome. In early 2006, Barrick Gold Corp acquired Placer Dome in a US$10.4bn takeover, and now wholly owns the Kanowna group of operations, which includes Kanowna Belle, the Paddington mill and various other open-pit gold mines in the area.

Mineral Gold Ore In Kanowna Belle

Kanowna Belle gold mine mineralization is mainly hosted within a large porphyritic granodiorite body (Kanowna Belle Porphyry) that has intruded a sequence of sedimentary and volcaniclastic rocks. A zone of intense structural disruption (Fitzroy Shear Zone) separates the deposit into hangingwall and footwall structural domains, and is the primary control on gold distribution. Gold mineralisation is locally associated with quartz-carbonate stockwork veins, breccia zones, sulphide-quartz-carbonate stringers and sheeted vein arrays. The generally tabular enveloping surface to mineralisation dips steeply to the south, has a high plunge to strike ratio and remains open at depth.

The orebody does not outcrop. Supergene-enriched oxide ore, lying some 35–45m below surface, is underlain by primary sulphide mineralisation. Some of the unaltered near-surface mineralisation is non-refractory, but with deeper reserves, the concentrates requiring roasting before leaching the gold content.

Gold Mining Methods And Mining Operations In Kanowna Belle gold mine

Kanowna Belle was initially operated and gold mining methods as an open pit and has since moved to an underground operation. Contractor Eltin Open Pit Operations was responsible for initial stripping, using a fleet of Liebherr 984 and 994 hydraulic excavators and Caterpillar 785 trucks, and for mining services until the open-pit bottom was reached at a depth of 220m. Underground production took over from the open pit in late 1998.

Eltin gold mining methods Underground Operations began work on the access decline and other underground developments in mid-1995. Although a shaft hoisting system was considered for the deeper levels, in mid-1999, North and Delta decided to continue the development of the mine using truck haulage, giving capital cost savings of more than AUS$50m over the mine life. The decline reaches a depth of 1,020m below surface, is 7.7km long and is being extended to provide access for exploration beneath the current reserves.

"In early 2006, Barrick Gold Corp acquired Placer Dome in a US$10.4bn takeover, and now wholly owns the Kanowna group of operations."

Underground resources are contained in five blocks of which Block A, the primary target, has now been mined out. Production now comes from the deeper blocks B, C and D, with the deepest, Block E, being evaluated. To date, long-hole open stoping has been used, with tailings paste backfill, but in 2004 Kanowna Belle started changing to a pillarless retreat mining system.

Equipment for underground has been supplied by Atlas Copco. Worth AUS$13m, the fleet consists of a Rocket Boomer 322S development drill rig, two Simba production drill rigs, a Boltec 335SH rockbolting rig, up to seven MT5000 50t-capacity mine trucks and up to three ST1800 Scooptrams. Ore is transported to surface up the ramp using a fleet of Caterpillar 775 haul trucks.

Gold Processing  In Kanowna Belle Gold Mine

The Kanowna Belle gold processing facilities are located adjacent to the Kanowna Belle mine and are designed to handle approximately 1.8 million tonnes of feed per annum. The plant has the capability to treat both refractory and free milling ores, through the flotation circuit and associated concentrate roaster circuit, including carbon-in-leach (CIL) gold recovery, or bypassing the flotation circuit and going directly to a CIL circuit that is designed to treat flotation tails. 

Rock mineral from mining is screened, with oversize being crushed to 200–250mm. A two-stage grinding circuit consists of ANI SAG and ball mills. Cyclone underflow from the ball mill forms the feed for primary flash flotation in a 23m³ cell. 

The cyclone overflow is also treated by flotation, with the final tailings being leached in a 750m³ tank with cyanide and lime. Gold from the tailings leach is recovered through a series of four adsorption tanks. The mill capacity has been expanded from 1.6Mt/y to 1.9Mt/y, while gold recoveries are usually 89–90%. 

Flotation concentrates are thickened then washed to remove chlorides. Two-stage exothermic, self-sustaining roasting is used to oxidise pyrite and remove arsenic. 

Calcine from the Dorr-Oliver fluidised-bed roasters is cooled, then treated with lime and cyanide solution, and with gold recovery on to activated carbon in a series of seven adsorption tanks. Loaded carbon is stripped in a desorption circuit, gold being recovered by electrowinning on to steel wool and subsequent smelting to produce doré bars.

Windfall Lake Gold Project and gold deposit in Quebec, Canada

The Windfall Lake Gold project is located in the province of Quebec, approximately 200 kilometres northeast of Val-d’Or and 115 kilometres east of the town of Lebel-sur-Quévillon and is accessible year-round through a network of well-maintained logging roads (Figure 1). The property is located north of the 49th parallel and is subject to the provisions of the James Bay and Northern Quebec Agreement executed in 1975. The Windfall Lake Gold project falls within the traditional territory of the Waswanipi Cree First Nation.

The Windfall Lake property is 100 percent owned by Oban Mining Corp. and comprises 285 individual claims covering an aggregate area of approximately 12,400 hectares.

Eagle Hill Exploration Corporation, recently acquired by Oban Mining Corp., has established an Advance Exploration Agreement with the Cree First Nation of Waswanipi, the Grand Council of the Crees (Eeyou Istchee), and the Cree Regional Authority regarding exploration and development of the Windfall Lake Gold Project.


The Windfall Lake property occurs within the Urban-Barry Greenstone Belt located in the eastern part of the Abitibi Subprovince. The Urban-Barry Greenstone Belt has an east-west extent of 135 kilometres and is 4 to 20 kilometres wide. Oban Mining is currently the largest stakeholder in the Urban Barry Greenstone Belt with over 40% of the land staked.

At the Windfall Lake deposit, the volcanic stratigraphy trends to the northeast and dips moderately towards the southeast. The tholeiitic volcanic rocks are intruded by a series of NE- to E-trending calc-alkalic porphyry dikes that are intimately associated in space and in time with the important gold mineralization. Alteration is principally silica-sericite-tourmaline with a peripheral chlorite-carbonate halo.
Figure 2. Geology map of the Abitibi Greenstone Belt with location of the Windfall Property in the Urban-Barry belt

Gold mineralization

The most significant gold mineralization defined to date on the Windfall Lake Property occurs in the Main Zone, located in central-south portion of the property. Additional gold mineralization is also present in the peripheral F-11, F-17, and F-51 zones (Figure 3).

The gold mineralization in the Main Zone occurs in several sub-vertical, northeast-trending lenses measuring between 2 and 35 meters in horizontal thickness. To date, better lateral and vertical continuity has been identified as a series of sub parallel lenses along the corridors of Zone 27, Caribou, and Mallard that all have the same style of gold mineralization associated with sulphide replacement, generally pyrite, occurring as disseminations, stockworks and breccias. Within the lenses, there are a number of sub-horizontal to shallow easterly plunging, higher grade, and more continuous shoots extending for over 700 meters along strike.
The gold-bearing pyrite stockwork mainly consists of pyrite stringers with minor tourmaline needles; the stringers are typically less than 1 centimeter in thickness and are oriented in several directions (Figure 4). Trace amounts of chalcopyrite, sphalerite, pyrrhotite, arsenopyrite, tetrahedrite, and bismuth sulfosalts are also present around pyrite grains but also as inclusions in pyrite of the pyrite stockwork. Specks of gold are sometimes visible in the pyrite stringers and also in semi-massive sulphide bands, tourmaline veins or in the altered part of the rock around these features.

The stockwork mineralization is hosted within volcanic rocks and various generations of porphyry dikes except for the Red Dog dikes, which postdate the emplacement of the pyrite stockwork. Some of the fragments in porphyry dikes were altered and mineralized prior to being brecciated and porphyry dikes locally crosscut the pyrite stockwork mineralization, suggesting that emplacement of the gold mineralization was broadly coeval with the intrusion of the porphyry dikes. The distribution of the pyrite stockwork is greatly influenced by the geometry of the dikes, specifically for Zone 27 and the Caribou corridor, which are spatially associated with 2- to 30-metre thick northeast-trending porphyry dikes (Figure 5)

Gold mineralization (several ounces per tonne) is locally associated with brecciated quartz veins with colloform and crustiform banding (Figure 6). The veins are moderately dipping and trend northeast-southwest. The largest zone is vein 466 in the Zone 27 corridor with a strike extent of 300 metres and a dip extent of 200 metres. At a minimum width of 0.5 metres and an average width of approximately 1.5 metres, the colloform-crustiform veins can reach a thickness nearly 6 metres, locally.

The auriferous zones are cross-cut at depth by the quartz monzonite Red Dog sill, which is up to 100 meters thick and dips approximately 30 degrees to the southeast. Drilling by Eagle Hill indicates that the gold mineralization continues below the Red Dog sill to a depth of at least 870 meters below surface and remains open along strike and at depth.

The characteristics of the gold mineralization in the Main Zone are similar to intrusion-related gold mineralization described as atypical greenstone-hosted deposits by Robert (2007). Although these atypical deposits display similar regional-scale controls and commonly occur in the same camps as orogenic deposits, they differ in styles of mineralization, metal association, interpreted crustal levels of emplacement, and relative age. Those atypical greenstone-hosted gold deposits show a close spatial association with high level porphyry stocks and dykes. The Kanowna Belle gold deposit in Western Australia would be a good analogy to Windfall Lake gold deposit.

Figure 3. Surface projection of gold zones of the Windfall Lake Gold Deposit with location of the existing underground decline.
Figure 4.Typical gold-bearing pyrite mineralization at Windfall Lake Gold Deposit. a) Outcrop of  pyrite stockwork; b) Fresh sample with pyrite stockwork and silica-sericite alteration; c) pyrite stockwork in core. Red numbers are gold values in grams per tonnes; d) pyrite stockwork and disseminated pyrite with tourmaline needles (small black dots).
Figure 5. Sub-surface projection of the gold lenses (in red) in relation with the porphyry dykes.
Figure 6. Core pictures of the high grade crustiform-colloform veins. Impressive visible gold in figure b.
Figure 7. Vertical cross-section through the Main Zone, looking to the NE. Additional gold bearing lenses were discovered below the Red Dog unit with similar grade and thickness than above the Red Dog. Those lenses remain open for expansion.

High-grade gold resource
A mineral resource update completed by SRK (Canada) in November 2014 estimated 748,000 ounces of gold at 8.42 g/t gold in the indicated category, and 860,000 ounces of gold at 7.62 g/t gold in the inferred category. The bulk of mineralization averages ~10 g/t over 5 metres, with very high-grade pockets up to 248 g/t over 12.4 metres in some areas. Drill holes in the gold zones demonstrate good grade distribution along the entire mineralized interval. Preliminary metallurgical tests indicate a gold recovery of 95.7% using a standard gravity and flotation circuit, followed by cyanidation.

Table 1. Mineral Resource Statement (From SRK Consulting, November 13, 2014).

Reported at a cut-off grade of 3.0 g/t gold, assuming an underground extraction scenario with an assumed gold price of US$1,200/oz and metallurgical recovery of 96%. Inferred resources have a great amount of uncertainty as to their existence and as to whether they can be mined legally or economically. It cannot be assumed that all or any part of the inferred resources will ever be upgraded to a higher category. Mineral resources are not mineral reserves and do not have demonstrated economic viability.

Resources : Oban Mining

Gold prospecting and gold deposit Kanowna Belle Australia

Gold prospecting in Kanowna Belle Australia was first discovered approximately 20 kilometres northeast of Kalgoorlie in Western Australia,  in 1893 about a year after Bayley and Ford discovered the Coolgardie Field and not long after Paddy Hannan located the gold-bearing alluvials that led to the discovery of the Golden Mile at Kalgoorlie-Boulder, also in 1893.

Kanowna Belle in Australiia lies hidden beneath a sand and thin sheetwash-covered plain dotted with salmon gums and bluebush about 18 kilometres northeast of Kalgoorlie. The old townsite of Kanowna and its surrounding vein, 'cement' and deep lead workings lie some two kilometres to the east and northeast of Kanowna Belle.

The deposit in Kanowna Belle Australia contains widespread and variable carbonate-sericite, sodic and minor silicic alteration. Pyrite is variably disseminated, occasionally veined, comprises between 1 and 5% of the rock by weight and is generally related to gold mineralisation. Other sulphide species or tellurides are present in minor amounts of less than 0.1% combined.

Gold mineralisation occurs with disseminated pyrite on and within discrete grains or blebs. Visible free gold is occasionally seen.Higher-grade zones frequently exhibit stringer-type quartz-pyrite veins. Generally, the bulk of the 5g/t Au mineralisation is associated with fine networks described as crackle-brecciation with sericite-carbonate alteration and variable silicification.

Gold production from Kanowna peaked in 1898 with just over 150,000 ounces produced from vein, 'cement' and deep lead sources. Production was sporadic between 1911 and 1946 when production, to all intents and purposes, ceased.

Interest in Kanowna surged again in 1979 as the gold price rose, resulting in increased exploration activity and, in 1986, the recommencement of mining at Kanowna. Total gold production from the Kanowna area is approximately one million ounces.

Exploration for additional mineralisation in the Kanowna area focussed on extending, or finding repetitions of known vein deposits and deep leads. Minor success was achieved on both fronts leading to the open pit mine on the old Ballarat and Last Chance vein systems (Delta Gold 67.5%, Pancontinental Mining 32.5%) and the commencement, after the amalgamation of leases to form the Golden Valley Joint Venture (Delta Gold 50%, Peko Gold 50%), of mining the deep leads for heap-leach treatment at the QED operation.

The Kanowna Belle discovery evolved as a conceptual model beginning as an occurrence of steeply dipping and narrow gold-bearing veins of limited extent - the interpretation placed on RAB results obtained in 1987 and 1988. A large area (400 metres by 300 metres) of anomalous gold-in-soil values, defined in 1989 in the area of the RAB drilling, was inconsistent with the concept. Follow-up RAB drilling and the discovery RC drill hole in December 1989 led to an alternative concept - that of a flat-lying but otherwise apparently structureless, supergene body which did not fit either a vein or deep lead concept.

Interpretation of deeper and more widespread (vertical) drilling results throughout 1990 demonstrated an elongation of the deposit to the southwest and suggested a southern dip direction. (It was the drilling of deeper holes GDD117, GDC118 and GDC119 late in 1990 that revealed the potential size of Kanowna Belle with intercepts of 50 - 80 metres of 2 - 5g/t Au).

Total production from the whole field, mostly from within a few kilometres of Kanowna, was approximately one million ounces - a significant field in the old days and certainly worth a serious look ten years ago.

Process Of Gold Mining And Gold Mining Production In Cortez Mine Nevada

The Cortez gold mine is located 100 kilometers southwest of Elko, Nevada in Lander County. The Cortez Pipeline property is 11 kilometers northwest and the Cortez Pediment property (which includes the Cortez Hills deposit) is four kilometers southeast of the original Cortez milling complex. The Pipeline and South Pipeline deposits are mined by conventional open-pit methods. The Cortez property covers approximately 2,800 square kilometers on one of the world’s most highly prospective mineral trends.

Process of gold mining in Cortez  Nevada United States of America

Conventional open-pit mining methods are used for the Pipeline and South Pipeline deposits, scheduled in nine stages. From 2001 to 2005, production averaged 70Mt/y. Mining is carried out with electric shovels, a hydraulic shovel and haul trucks. A fleet of miscellaneous equipment includes rotary/hammer blasthole drills, wheel loaders, bulldozers, graders and water trucks.

A pit dewatering system including 40 wells helps to prevent water inflows, the water being transported from the pit to a series of shallow infiltration ponds for recycling.
The original Cortez concentrator was placed on care-and-maintenance in late 1999, following the change from milling ore to heap-leaching ore from the Pipeline pit. Consisting of crushing, dry grinding, circulating fluid bed roasting, wet grinding and carbon-in-leach gold recovery facilities, it may be re-opened to treat suitable ore towards the end of the mine’s life.

The Pipeline concentrator has a throughput of 8,650t/d, having been designed to handle various types of oxide ore from the Pipeline and South Pipeline orebodies. Its flowsheet consists of primary crushing, autogenous/ball mill (AG) grinding, carbon-in-leach and carbon-in-column gold recovery systems, together with carbon stripping, reactivation and gold refining facilities. Low-grade, run-of-mine oxide ore is heap-leached, with gold-bearing carbon from this section being returned to the main concentrator for gold recovery.

Run-of-mine oxide ore is crushed and stockpiled before grinding in an autogenous mill and a ball mill. Discharge from the AG mill is screened, with screen oversize being conveyed to a cone crusher and recycled to the AG mill. Screen undersize and ball mill discharge are sized in hydrocyclones, the overflow being thickened to provide feed for the carbon-in-column (CIC) and carbon-in-leach (CIL) circuits.

The CIL circuit consists of eight CIL tanks, 16 screens and eight carbon-forwarding pumps. Retention time at the 9300t/d throughput rate is 44 hours, increasing to 54 hours when milling South Pipeline ore at 7500t/d. The CIC circuit consists of six carbon columns with a retention time of 18 minutes. After stripping the carbon using a pressurised Zadra process, the gold is recovered by electrowinning on to stainless steel wool cathodes. The filter cake is dried, melted in an induction furnace and poured into doré bars assaying approximately 90–94% gold and 3–6% silver for shipping to commercial refineries.

Gold mining production process Cortez  Nevada United States of America

The mine produced 902,000 ounces of gold in 2014 at all-in sustaining costs of $706 per ounce1. In 2015, production is expected to be 825,000-900,000 ounces at all-in sustaining costs of $760-$835 per ounce.

Proven and probable mineral reserves as at December 31, 2014, were 9.85 million ounces of gold.

Production began at Cortez in 1969 with the Pipeline deposits, where mining is now centred, being discovered subsequently. "Proven and probable reserves in January 2005 totalled 234Mt grading 1.4g/t gold, equivalent to 7.8Moz of gold at 74% recovery."

The Pipeline deposit is situated along the Cortez/Battle Mountain trend in the north-central Nevada basin-and-range province. Submicroscopic gold particles are evenly distributed throughout carbonate host rocks. The two principal lithological units are a sheared and altered thinly-bedded calcareous siltstone and quaternary alluvium varying from chert, argillite, siltstone, limestone and quartzite to fine sands and silts.

Proven and probable reserves in January 2005 totalled 234Mt grading 1.4g/t gold, equivalent to 7.8Moz of gold at 74% recovery. In September 2005, the joint venture approved the development of the nearby Cortez Hills deposit, discovered in 2003, where proven and probable reserves of 64.7Mt at a grade of 1.8g/t gold contain a further 5.5Moz.

A prefeasibility study for underground mining at Cortez below currently permitted levels will be completed in late 2015. Mineralization in this zone is primarily oxide and higher grade compared to the current underground mine, which is sulfide in nature. The limits of the Lower Zone have not yet been defined, and drilling has indicated the potential for new targets at depth. The exploration drift has been extended to the south, enabling additional step-out drilling, which is anticipated to begin in June. Drill results to date include 36.6 meters at 31.5 grams per tonne and 27.4 meters at 20.9 grams per tonne, both oxide in nature, which compare favorably with the average grade of 13.8 grams per tonne in refractory ore above the 3,800 foot level.

How To Process Gold Ore In Yanacocha Gold Mine Peru

Yanacocha is South America's largest gold mine, located in the province and department of Cajamarca, approximately 800 kilometers northeast of Lima, Peru. Yanacocha’s operations are situated between 3,500 and 4,100 meters above sea level with development activities in four primary basins. The operation is a joint venture between Newmont (51.35%), Minas Buenaventura (43.65%) and the International Finance Corporation (5%)

The Yanacocha gold district is a 10x4km zone of altered rocks within a belt of tertiary volcanics that extends the whole length of Peru. Andesitic domes and dome complexes have been silicified and leached by epithermal gold-bearing solutions in at least nine distinct deposits. The mineralised sequences, which can also contain significant amounts of silver, are flanked by extensive argillitic alteration, and subsequent events have created siliceous breccia pipes with localised high gold grades.

How To Process Gold Ore In Yanacocha Gold Mine Peru
The process of gold from mining the first is drilling using Ingersoll-Rand DM45E and Atlas Copco machines and blasting are the responsibility of Minera Yanacocha. elimination of materials containing gold and silver began with drilling the ground to make a hole that will then condition with explosives..

The explosions carried out and the subsequent removal of ground begin to form large holes in the ground called pits. Stone materials have been destroyed and then transported by haul trucks ( which can load up to 250 tons of mineral rock) The ore is transported 2.5km or more to the leach pads using wheeled loaders and 85t-capacity trucks, and is heaped by stackers

Heap leaching is the process to extract precious metals like gold, silver, copper and uranium from their ore by placing them on a pad (a base) in a heap and sprinkling a leaching solvent, such as cyanide or acids, over the heap. This process dissolves the metals and they collect at the bottom of the pad.
Ground Preparation and pad construction: Here the soil on a slightly sloping ground is compacted and covered by an impermeable pad (can be made of plastic). Ore stacking: Then the crushed ore is stacked in the form of big heaps. Amount of fines is decreases as low as possible to improve permeability. Then the leaching agent such as cyanide or acid is sprayed over the heap. As, the reagent passes through the heap; the valuable metals get dissolved in it. The solution containing metal is drained from the heap and collected in a pond and the solution is sent for subsequent process for metal recovery to the processing plant.

With gold mineral processing plant ball mill trying to process the metal that can not be obtained by heap leaching. Gold recovered within 24 hours, unlike the heap leach process lasted almost 60 days. Construction began in mid-2006 and concluded in early 2008, with an investment of 270 million dollars and the production plan for 9 years. 1500 workers participated in the construction of this important project which has a processing capacity of 5,000,000 tons / year.

Carbon In Columns comprise the cyanide leach solution, and agitated in the leach tanks, and agitated with the ore while the gold is being dissolved. This assures a rapid interface between the carbon and the gold loaded cyanide solution.  Granular, hard carbon is used, in the size range of 10-16 mesh. The carbon is then removed by screening, across a carbon screen, allowing the liquid and finely ground ore (-100 mesh) to pass through easily, and retaining the carbon on the screen.  The pregnant cyanide solution flows through the carbon columns, which are generally situated in step fashion, so that the overflow from the highest column will gravity flow to the next column, alleviating the requirement for pumping. The gold adsorbs onto the surface of the carbon. The loaded carbon is periodically removed from the columns, and sent to the stripping circuit.

The gold obtained in the Merrill Crowe process is subjected to operations of drying kiln retort at 650 ° C. Finally, the obtained product undergoes a process of smelting electric arc furnace to 1,200º C for the Dore, a bar made of a mixture of gold and silver. After recovery, the contained metal is smelted and cast as 400oz doré bars containing 75% gold and 20% silver. The UK-based refiner Johnson Matthey is responsible for shipping the bars.