Overview
Stage | Pre-Feasibility |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Mechanized Cut & Fill
- Overhand Cut & Fill
- Underhand Cut & Fill
- Sub-level stoping
- Longhole stoping
- Paste backfill
|
Processing |
- Gravity separation
- Flotation
|
Mine Life | 8 years (as of Jan 1, 2016) |
Source:
p. 17
Company | Interest | Ownership |
GoldQuest Mining Corp.
|
100 %
|
Indirect
|
GoldQuest Dominicana SRL
|
100 %
|
Direct
|
GoldQuest Mining (BVI) Corp.
|
100 %
|
Indirect
|
GoldQuest owns a 100% interest in the Tireo Property and Romero Project through its wholly owned Dominican subsidiary, GoldQuest Dominicana), via GoldQuest Mining (BVI) Corp., a British Virgin Islands company.
Deposit Type
- Epithermal
- Breccia pipe / Stockwork
- Vein / narrow vein
Summary:
Romero is located on the south side of the Central Cordillera of Hispaniola and is hosted by the Cretaceous-age Tireo Formation volcanic rocks and limestones, which formed in an island arc environment. The deposit geology is a relatively flat lying sequence of intercalated subaqueous, intermediate to felsic volcanic and volcaniclastic rocks and limestones on the west side of thick rhyolite flows or domes. Mineralization is relatively stratabound and flat lying and is mainly hosted by a dacite breccia tuff.
Mineralization outcrops in a number of places were eroded by rivers and streams, and continuity under barren cap rock has been demonstrated by drilling. Hydrothermal alteration and gold mineralization can be traced for over 2,200 m from Romero to Romero South and beyond to the south.
The thickness of the altered dacite tuff breccia horizon is up to about 65 m at Romero South and up to more than 200 m (open) at Hondo Valle and Romero. The mineralized horizon is capped by limestone or dacite to andesite lavas.
Mineralization is intermediate sulphidation epithermal in style. The mineralization is associated with quartz-pyrite, quartz-illite-pyrite and illite-chlorite-pyrite alteration. Alteration is generally strongest in the upper part of the mineralized zone and decreases in intensity with depth. Gold mineralization is associated with disseminated to semi-massive sulphides, sulphide veinlets and quartz-sulphides. The sulphides comprise pyrite with sphalerite, chalcopyrite and galena. Oxidation is shallow, to a depth of 10 m to 15 m.
High grade mineralization at the Romero deposit takes the shape of vertically stacked sub-parallel irregular lenses which generally dip to the northeast at an average angle of 20°. Each lens ranges in thickness from 10 m to 40 m in the middle and generally tapers to zero width at the edges, but the continuity of the lenses in all directions is inconsistent. The spacing between lenses is also inconsistent and ranges up to 50 m. Generally, lower grade mineralization surrounds the higher grade lenses.
The strike length of the main portion of the mining resource is 430 m. Two smaller pods of high grade mineralization exist approximately 200 m along strike to the southeast of the main larger main economic body. The deepest mining level is 420 m below surface (680 m level) and the highest mining level is 85 m below surface (1,000 m level), meaning the total vertical extent of the mining resource is 320 m. Perpendicular to strike, the deposit is about 170 m wide.
Mining Methods
- Mechanized Cut & Fill
- Overhand Cut & Fill
- Underhand Cut & Fill
- Sub-level stoping
- Longhole stoping
- Paste backfill
Summary:
Two mining methods are proposed for the Romero deposit, sub-level long hole (LH) stoping and mechanized cut and fill (MCF). A combination of paste backfill and develop waste rock fill will be used in mining sequence. LH stoping will be used in areas of complete ground strength and generally thick Mineral Resources. MCF will be utilized in the areas of pour ground conditions and/or thin Mineral Resources which does not warrant LH stoping.
Long hole (LH) stoping provides high productivity at low cost from a small number working faces. All stopes will be fixed with a mixture of paste fill and/or development waste.
Geotechnical design have determined stope sizes of 30 m along strike, with widths up to 15 m wide and sub-level intervals of 20 m. Stope extraction sequencing is planned to be in a primary-secondary fashion with the lower stopes leading the stopes above. Primary and secondary stopes are sized equally at 15 m wide. After the primary stopes are mined, they will be filled with cemented paste backfill of adequate strength to allow exposure of 20 m high x 30 m long fill wall adjacent to the secondary stopes that will be mined alongside. Two lifts of primary stopes will be mined before the first secondary stopes are started to allow the drilling drifts to be reused as mucking drifts for the next sub-level above and to minimize the stoping span.
LH stopes will be developed by driving a central ore drift up to a mineralization thickness to a maximum 5 m by 4 m hight access drift central to the stope.
A slot raise will be developed at one end of the stope by LH drilling and short stage blasting from the bottom up using the drop-raise blasting techniques. The slot raise will be enlarged to form a slot across the full width of the stope.
Vertical ring of drill holes will be blasted into the stope and mineralized material will be mucked from the bottom of the stope by load-haul-dump (LHD) machines with remote control.
No rib pillars were planned and the stoping sequence with the paste backfilling will allow 100% extraction in the LH stoping blocks.
Mechanized cut and fill mining will be utilized in thinner areas where LH stopes are not economic. MCF will also used in areas of poor ground conditions where larger stope are not geotechnically possible. MCF is a lower productivity, higher cost mining method than LH stoping, but provides highly selective mining with minimal dilution. Stopes can be sized with irregular back and walls to match the ore boundaries.
A two boom, electric hydraulic jumbos will drill 4.88m (16 foot) long rounds on a standard development heading pattern. The drilled holes will be charged with high explosive primers and ANFO and initiated with non-electric caps. After blasting, the heading will be washed, scaled and blasted ore will be mucked with LHDs into trucks and hauled to surface. Ground support will then be installed with a mechanized bolter as required.
Two types of MCF will be utilized at Romero. Overhand MCF accounts for 73% of MCF mining, and 11% of all production. In overhand MCF each mining block is accessed by an attack ramp and mined in 4 m high lifts. Stopes are developed on the lowest level first, and each subsequent stope or 4 m lift is developed above the depleted and backfilled stope. Mining direction is bottom up.
Underhand MFC accounts for 27% of MCF mining, and 3% of all ore production. In underhand cut and fill an MCF stope is mined out and backfilled with a high strength structural paste fill, after it has been prepared with additional ground support on the floor. Once the structural paste fill has cured the next 4 m lift will commence underneath the filled stope. Mining direction is top-down.
The requirement of both mine methods is a byproduct of optimizing the LH stope production schedule, and avoiding the requirement to mine through backfilled areas to gain access to MCF zones.
Processing
- Gravity separation
- Flotation
Flow Sheet:
Summary:
The flowsheet consists of primary crushing, SAG and ball mill grinding, gravity separation, flotationm dewatering and filtration. Tailings will either be dry stacked or combined with cement and pumped underground as paste backfill.
The concentrate will be transported to designated smelters worldwide for subsequent reduction into copper metal. Mill throughput is designed to be approximately 2,800 dry tonnes per day (dt/d). Total annual concentrate production will be approximately 64,000 t.
The mineral processing facility will be located south of the Romero mine site. Listed below are the major process unit operations at Romero:
- Primary jaw crusher;
- Crushed stockpile (live capacity 2,800 tonnes);
- Conveyance of material from the crusher building to the stockpile and onto the main process facility;
- Mill building will contain:
o Semi-autogenous grinding and ball mills and gravity concentration within closed circuit cyclone c ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Gold
|
Recovery Rate, %
| ......  |
Gold
|
Head Grade, %
| 3.72 |
Gold
|
Concentrate Grade, %
| ......  |
Copper
|
Recovery Rate, %
| ......  |
Copper
|
Head Grade, %
| 0.88 |
Copper
|
Concentrate Grade, %
| ......  |
Silver
|
Recovery Rate, %
| ......  |
Silver
|
Head Grade, g/t
| 4.33 |
Silver
|
Concentrate Grade, g/t
| ......  |
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Projected Production:
Commodity | Product | Units | Avg. Annual | LOM |
Gold
|
Metal in concentrate
|
koz
| | 640 |
Copper
|
Metal in concentrate
|
M lbs
| | ......  |
Copper
|
Concentrate
|
dmt
| ......  | ......  |
Silver
|
Metal in concentrate
|
koz
| | ......  |
Operational Metrics:
Metrics | |
Daily milling rate
| 2,702 t * |
Daily mining capacity
| 2,800 t of ore * |
Daily milling capacity
| 2,800 t * |
Annual mining capacity
| 1,022 kt of ore * |
Waste tonnes, LOM
| 940 kt * |
Ore tonnes mined, LOM
| 7,031 kt * |
Total tonnes mined, LOM
| 7,971 kt * |
Tonnes milled, LOM
| 7,031 kt * |
* According to 2016 study.
Reserves at September 27, 2016:
Category | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
7,031 kt
|
Gold
|
3.72 g/t
|
840 koz
|
Probable
|
7,031 kt
|
Copper
|
0.88 %
|
136 M lbs
|
Probable
|
7,031 kt
|
Silver
|
4.33 g/t
|
980 koz
|
Probable
|
7,031 kt
|
Gold Equivalent
|
5 g/t
|
1,126 koz
|
Indicated
|
20,230 kt
|
Gold
|
2.67 g/t
|
1,738 koz
|
Indicated
|
20,230 kt
|
Copper
|
0.61 %
|
|
Indicated
|
20,230 kt
|
Silver
|
4 g/t
|
|
Indicated
|
20,230 kt
|
Zinc
|
0.3 %
|
|
Indicated
|
20,230 kt
|
Gold Equivalent
|
3.48 g/t
|
2,265 koz
|
Inferred
|
3,020 kt
|
Gold
|
2.03 g/t
|
197 koz
|
Inferred
|
3,020 kt
|
Copper
|
0.33 %
|
|
Inferred
|
3,020 kt
|
Silver
|
29 g/t
|
|
Inferred
|
3,020 kt
|
Zinc
|
0.32 %
|
|
Inferred
|
3,020 kt
|
Gold Equivalent
|
2.47 g/t
|
240 koz
|
Mine Management:
Job Title | Name | Profile | Ref. Date |
.......................
|
.......................
|
|
Feb 2, 2020
|
.......................
|
.......................
|
|
Feb 2, 2020
|
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