It was founded in 1980 by our partners who have been carrying out chrome and zinc mining operations successfully for 40 years, in order to operate the mining site containing complex Lead-Copper-Zinc ores in Gumushane. It gained its current company structure, owing to our partnership since 2005.


In addition to its operations in Gumushane, Gumustas Mining Inc. expanded its field of business in 2007 by acquiring Nigde-Bolkar Gold-Silver mine, which was one of the major mining sites in Turkey.


In 2011, Gumustas Mining got into a partnership by 50% in the operation of the Gold-Silver mine of Esen Mining Inc., which was located in our Adjacent Site in Bolkar, Nigde and continues its production activities in this company.


As Gumustas Mining, we plan to be a major Gold-Silver and Metal mineral manufacturer in Turkey, thanks to the projects we accomplish rapidly, new investments and the project we will implement in the coming years.


Exploration & Production Operations

Businesses in operation;

  • Gumushane Hazine Magara Zinc, Lead, Copper Underground Plant
  • Gumushane Zinc, Lead, Copper flotation plant
  • Nigde-Bolkar Madenkoy Gold, Silver, Lead, Zinc Underground Plant
  • Nigde Tepekoy Gold-Silver Enrichment Plant


Exploration projects;

  • Gumushane Kırkpavli Gold, Silver, Lead, Zinc, Copper Exploration Project
  • Adiyaman Tut Site Copper Exploration
  • Bolkardag Sulphure Complex Ore Exploration Project
  • In addition, geochemical and geological surveys are underway at potential sites in various regions of Turkey.


In order to operate and introduce Nigde-Bolkar mineral deposits to the national economy; it has maintained the exploration + preparation activities non-stop since 2007 and made investments in ore production and enrichment facilities at the mining site based on the positive results obtained. Our company in Nigde-Bolkar produces Gold and Siler ores, whch are classified as precious metals.

Mining started with the Hittites in 800 B.C. circa in the Bolkar Mountains situated in the Middle Taurus and was operated  by Romans, Byzantines and Ottomans in different periods until Republican history. In the past, high-grade sulphur lead ore would have been produced and smelted in nearby villages to produce metal lead and silver.


Today, our mining operations produce Au, Ag, Zn ore and sell blended oxide Zn ore directly. Once produced, oxide Au and Ag ore is processed in Tepekoy plant to derive dore gold and silver ingots.


Moreover, feasibility and preparation works are underway for the production of sulphur Pb, Zn ore, which are detected in depths (elevations 1.400) within the scope of the exploration projects.


Work site is at an altitude of 1.650 m and the mines actively in operation are situated at altitudes between 1.900 – 2.450. A total of 220 people are employed at the mine.


The ore obtained from Bolkardag underground mines is transferred by transport vehicles to Tepekoy Ore Beneficiation Facility and processed by means tank leaching method to obtain gold and silver ore. Ore Beneficiation plant processes 20,0 dry tons of blended ore/hour and carries on the operations 24 hours 365 days the average grade of the ore fed to the plant is: Gold ~ 8.5 gr/ton and Silver (Ag) ~ 220 gr/ton.

Crushing – Screening

Gold – Silver ore must be brought to the appropriate grain size in order to go through the leaching process. So, crushing and screening process is performed in a system comprising a jaw-crusher, a hammer-crusher, screening systems and conveyor belts.


The milling/grinding process is carried out by means of 2 ball-mills and the second mill run in a closed-circuit cyclone system. The purpose of the unit is to ensure that 80% of the grain is reduced to a size below 74 microns. In this way, surface area will be further widened and cyanide can penetrate each and every single grain.

Hot Lime

Once milled, the ore (pulp) is heated up to around 85 °C and subjected to pre-leaching to decompose the jarosite (KFe3(SO4)2(OH)6) mineral. Thus, the inseparable gold and silver breaks up. The temperature is maintained by superheated oil piping system installed in the tanks. Hot lime application is rarely used in the world, but we use it only in one of our operations in Turkey.

Leaching Unit

Pulp from the hot lime unit is supplied to 4 leaching tanks fitted with mixers, each of which has a volume of 412 m3. Cyanide and oxygen (air) are added to the leaching tanks and thus the gold and silver in solid state are transferred to the liquid phase.

Solid - Liquid Separation

Once in liquid form, the gold and silver are subjected to liquid-solid separation process in the thickener tank. This system is also called counter current decantation. Flocculant (precipitator) is added to the tanks in this unit, allowing the solids to settle, after which it is sent to the detox unit, while the loaded upper current is sent to the recovery unit.

Solution Preparation

The upper current from the first thickener tank is pumped into the fine filtration unit. In this unit, the pollution rate of the contaminated solution coming from the thickener unit is reduced to less than 5 ppm. Once cleansed, the solution is sent to the deairing tower to reduce the dissolved oxygen content to less than 1 ppm and to make the gold and silver settle by adding zinc dust. This process is called Merril Crowe.

Decomposition (Detox)

The waste sent to the detox unit contains some cyanide. Before this waste solution is sent to the waste storage area, it goes through a process of chemical decomposition or stable precipitation to break up the cyanide it contains. Some chemicals (such as Sodium Metabisulphite, Copper Sulphate, and Sulfuric Acid etc.) are added to the system for degradation purposes. Once decomposed of cyanide, the pulp is pumped to the waste storage area.

Smelter (Casthouse)

The gold and silver concentrate, once precipitated in the press filters, is charged to the casting crucible/ladle as hot as 1250 0C. Remelting is helped with burner. Before remelting, some chemicals are added to the concentrate due to their slag-forming effect. The molten metal is cast into moulds and the slag is removed, after which they are numbered and weighed on a precision scale.

Waste Storage Area

The pulp pumped from the decomposition unit is collected in the waste storage area. The solution in the waste sent to the storage area is re-used in the system as process water with the help of the pump available in the area. According to the results of the analyses conducted by Accredited Laboratories, the amount of cyanide in the waste storage area was found to be lower than 1 ppm.

Chemical Reagent Feeding Unit

Solution preparation and feeding tanks as well as dosing pumps are available for sodium cyanide, copper sulphate, sodium metabisulphite and sulfuric acid, which are the chemicals used at the plant.


We have a Chemical Analysis Laboratory for process control and other chemical analyses and a technological test laboratory to carry out R & D studies. The analysis of precious metals such as Gold, Silver, Lead, Zinc, Copper, Iron in particular as well as other elements, inspection of the chemicals used in our operations and dore analyses are carried out.


Technological tests are carried out in our R&D Laboratory for maximum recovery of daily ores to be processed at the plant and for development of processes.

Research and development tests are carried out in order to achieve maximum recovery of the blended ore to be processed, by testing various parameters used at the operations on a weekly basis. The parameters that are obtained based on the results of the analysis are used in the operations.

Co-Gen Building

There is a 3-MW cogeneration system operating on site. The cogeneration system was added to the system to supply the power and heat energy required for the plant. The cogeneration plant to be located within the facility has the capacity to generate 1.242 kW thermal and 1.286 kW electrical power. Cogeneration system runs on Natural Gas (LNG).


Gumustas – Gumushane Mining site is located 2 km southwest of Gumushane in the Eastern Black Sea Region. Our license #IR-8479 covers the locality of Hazine Magarasi which was an ancient mine operation from 1200s. It is described as polymetallic Pb-Zn-Cu (Au-Ag) deposit. Production is carried out in the form of underground operation.

Our Mineral Beneficiation Plant is 18 km from our Mining operation. Flotation method is employed to produce Lead, Zinc and Copper concentrates separately. Lead and Copper Concentrates include Gold and Silver, as well.

Geology and Mineralization

Hazine Magarasi is defined as a polymetallic sulphide Pb, Zn, Cu, Au and Ag deposit, which is controlled by the tectonic zone, in the direction of N040oW with a 40-60o declivity to South West.

Rocks at the Site;

Andesite-basalt lava and pyroclastics, Quartz porphyry (Gumushane granite is pushed from south over to the young units and it entered a series of Eocene granodiorite.

The mineralization is settled in massive limestones. Two types of mineralization have been identified. The first one is Black Ore containing Pb-Zn (Au-Ag) and the second is Yellow ore containing Pb-Zn-Cu (Au-Ag) with a high Pyrite content.

Gumustas has made significant investments to determine the potential of the mine site since 2005: 188 surface drillings measuring 34.538 meters and 198 underground drillings measuring 12.627 meters, totalling 386 boreholes measuring 47.165 meters, were drilled till the end of 2013, as a result of which 6.300.000 tons of ore reserves were explored.


At this reserve; the first species is the mineralization with 1,81 g/ton Au, 77,11 g/ton Ag, 1,1% Cu grade, which contains high pyrite. The second species is the mineralization with 2,83% Pb and 4,95% Zn, Cu: 0,3 grade, with a content of Au:0,8 gr/ton, Ag: 65 gr/ton in the direction of N70oW and with a 60o declivity to the southwest.

Gumushane granite was pushed from south over to the young units and it entered a series of Eocene granodiorite.

The mineralization is settled in massive limestones. Two types of mineralization have been identified. The first one is Black Ore containing Pb-Zn (Au-Ag) and the second is Yellow ore containing Pb-Zn-Cu (Au-Ag) with a high Pyrite content.

Gumushane Lead – Zinc – Copper Flotation Plant

The ores produced at our mining facility are transported by land to our ore enrichment facility, which is located at a distance of 18 km, at Gumushane organized zone, where floatation method is used.


Black ore contains Sphalerite, galenite, pyrite and small amounts of chalcopyrite

Yellow ore contains Pyrite, Chalcopyrite, Sphalerite, galenite and fahlerz minerals.

Plant capacity is capable of processing 400.000 tons blended ore/year.

Concentrate Production: of the concentrates with Gold and Silver content;

Zinc Concentrate: 28.273 tons/year

Lead Concentrate: 11.555 tons/year

Copper Concentrate: 4.737 tons/year

Crusher Unit;

It is composed of hopper-vibration-feeder, Jaw Crusher, Horizontal-shaft impact crusher, vibrating screen and conveyor belts. To prevent dust formation, a high-tech Jet-Pulse Dust Filter is installed.


Milling Unit

Grinding is carried out in two stages. Both stages use Ball-mills.


Floatation Unit

Flotation Unit consists of Lead-Zinc, Copper Selective circuits. Flotation circuits are arranged with Cylindrical Flotation Tanks. Conventional Flotation Cells are used in the Lead Copper Selective circuit.


Filter Unit

It consists of Press Filters and Drum-Filters.


Waste Storage Unit

The waste storage area is built water tight and constructed in dam norms. The mixture (solid waste+water) from the process is cleaned through solid precipitation at the waste storage area, after which it is fed back to the process, running in closed circuit.


Karşıyaka Mah. Osmanbey Cad. Alkan Apt No:22 Merkez/Gümüşhane

+90 456 213 81 92

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