Overview
Status | Temporary Suspension |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Gravity separation
- Flotation
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Merrill–Crowe
- Solvent Extraction & Electrowinning
- X-Ray sorting
- Cyanide (reagent)
|
Mine Life | 11 years (as of Jan 1, 2017) |
Almaden Announces Mexican Federal Government Issues Decree to Temporarily Suspend All Non- Essential Businesses, Including Mining and Exploration, Until April 30, 2020 Due to COVID-19. |
Latest News | Almaden Provides Update on Permitting for Ixtaca Precious Metals Project, Mexico December 21, 2020 |
Source:
p. 16
Company | Interest | Ownership |
Almaden Minerals Ltd.
|
100 %
|
Indirect
|
Compania Minera Gorrión S.A. de C.V.
|
100 %
|
Direct
|
The Tuligtic Property is held 100 percent (%) by Compania Minera Gorrión S.A. de C.V. (Minera Gorrión), a wholly owned subsidiary of Almaden Minerals Ltd.
Deposit Type
- Epithermal
- Vein / narrow vein
Summary:
The principal deposit-type of interest on the Tuligtic Property is low- to intermediate- sulphidation epithermal gold-silver mineralization. This style of mineralization is recognised at the Ixtaca Zone but property scale high level epithermal alteration suggests that mineralization of this type can exist elsewhere on the Project. These deposits are described more fully below. The Tertiary bodies intruding the Tamaulipas Limestones and the tertiary volcanics, makes the Property also prospective for Porphyry copper-gold-molybdenum (Cu-Au-Mo) and peripheral Pb-Zn Skarn deposits.
Two styles of alteration and mineralization are identified in the area: (1) copper- molybdenum porphyry style alteration and mineralization hosted by diorite and quartz- diorite intrusions; (2) silver-gold lowsulphidation epithermal quartz-bladed calcite veins hosted by carbonate rocks and spatially associated with overlying volcanic hosted texturally destructive clay alteration and replacement silicification.
Outcropping porphyry-style alteration and mineralization is observed in the bottoms of several drainages where the altered intrusive complex is exposed in erosional windows beneath post mineral unconsolidated ash deposits. Multiple late and post mineral intrusive phases are identified crossing an early intensely altered and quartz-veined medium-grained feldspar phyric diorite named the Principal Porphyry. Other intrusive types include late and post mineral mafic dykes and an inter-mineral feldspar-quartz phyric diorite. Late mineral mafic dykes are fine grained and altered to chlorite with accessory pyrite. Calcsilicate (garnet-clinopyroxene) altered limestone occurs in proximity to the intrusive contacts and is crosscut by late quartz-pyrite veins. Early biotite alteration of the principal porphyry consists of biotiteorthoclase flooding of the groundmass. Quartz veins associated with early alteration have irregular boundaries and are interpreted to be representative of A-style porphyry veins. These are followed by molybdenite veins which are associated with the same wall rock alteration. Chalcopyrite appears late in the early alteration sequence. Late alteration is characterized by intense zones of muscovite-illite-pyrite overprinting earlier quartz-K-feldspar-pyrite ± chalcopyrite veining and replacing earlier hydrothermal orthoclase and biotite. Stockwork quartz-pyrite crosscuts the A-style veins and is associated with muscovite-illite alteration of biotite. The quartz-sericite alteration can be texturally destructive resulting in white friable quartz-veined and pyrite rich rock. Pyrite is observed replacing chalcopyrite and in some instances chalcopyrite remains only as inclusions within late stage pyrite grains.
The veining of Ixtaca epithermal system displays characteristics representative of intermediate and low sulphidation deposits. These include typical mill feed and gangue mineralogy (electrum, sphalerite, galena, adularia, and carbonates), mineralization dominantly in open space veins (colloform banding, cavity filling). Assaying has indicated high contents of gold and silver. The high gold contents are rare in Mexico, where epithermal systems are dominantly silver-rich. Mineralized hydrothermal breccias showing multiphase development are commonly encountered within the main veins. Hydrothermal silicic/carbonate breccia zones occur within the limestone and dip steeply. These breccias are dominantly controlled by the main faults.
The Upper Tamaulipas formation, the dykes that crosscut it and the upper Coyoltepec volcanic subunit are the main host rocks to the epithermal vein system at Ixtaca. In the Main and Ixtaca North zones, veining strikes dominantly ENE-WNW (060 degrees) parallel to a major dyke trend and at a very high angle to the N to NNW bedding and fold structures within the limestones.
Studies of mineral assemblages in hand specimen, transmitted and reflected light microscopy and SEM analyses have been carried out in order to construct a paragenetic sequence of mineral formation. This work completed by Herrington (2011) and Staffurth (2012) reveals that veining occurs in three main stages. The first stage is barren calcite veining. This is followed by buff brown and pink colloform carbonate and silicate veins containing abundant silver minerals and lower gold. The third stage of veining contains both gold and silver mineralization. The dominant gold-bearing mineral is electrum, with varying Au:Ag ratios. The majority of grains contain 40-60wt (weight) % gold but a few have down to 20wt% (Staffurth, 2012). Gold content occasionally varies within electrum grains, and some larger grains seem to be composed of aggregates of several smaller grains of differing composition (Staffurth, 2012). Electrum often appears to have been deposited with late galena-clausthalite both of which are found as inclusions or in fractures in pyrite. It is also closely associated with silver minerals as well as sphalerite and alabandite. Gold is also present in uytenbogaardtite (Ag3AuS2). This mineral is associated with electrum, chalcopyrite, galena, alabandite, silver minerals, and quartz in stage three mineralization (Herrington, 2011; Staffurth, 2012). Apart from electrum, the dominant silver bearing minerals are polybasite (-pearceite) and argentian tetrahedrite plus minor acanthite-naumannite, pyrargyrite and stephanite. They are associated with sulphides or are isolated in gangue minerals (Staffurth, 2012).
The vein-related mineralization at Ixtaca does not have hard geologic boundaries. The mineralized zones are essentially vein zones, the outer boundaries of which are grade boundaries associated with decreased vein density.
Summary:
The Ixtaca gold-silver project in the PFS is planned as an open pit mining operation using contractor mining with initial production in 2019 at a mill feed rate of 7,650 tonnes per day during Years 1-4 and a ramp up to 15,300 tonnes per day from Year 5 onwards.
Estimated mining inventory is comprised of 326 million tonnes of rock and 65 million tonnes of mill feed with an average mill feed grade of 0.62 grams per tonne gold and 37.7 grams per tonne silver. A total of 1.04 million ounces of gold and 70.9 million ounces of silver would be produced over the 14 year mine life.
The ultimate open pit is separated into seven mining phases. The mine plan consists of one year of pre-stripping (prior to ore processing start-up), and fourteen years of open pit mining. Stockpile reclaim will be fed to the processing facility throughout the mine life. All open pit ore and reclaimed stockpile material will be fed to a primary crusher near the pit rim and transported to the processing facility on an overland conveyor.
Processing
- Gravity separation
- Flotation
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Merrill–Crowe
- Solvent Extraction & Electrowinning
- X-Ray sorting
- Cyanide (reagent)
Flow Sheet:
Summary:
The Study reflects the Rock Creek process plant which has been purchased by Almaden. Run of mine ore will be crushed in a three-stage crushing circuit to -9 mm.
The Study also incorporates ore sorting, test work for which has shown the ability to separate barren or low grade limestone host rock encountered within the vein swarm from vein and veined material. Product from the secondary crusher will be screened in to coarse (+20mm), mid-size (12 to 20 mm), and fine (-12mm) fractions. Coarse and mid-size ore will be sorted by an XRT ore sort machine to eject waste rock. Fine ore will bypass the ore sorting and is sent directly to the mill.
Ore sort waste from Limestone and Black Shale is below waste/ore cutoff grade and is placed in the waste rock dump. Ore sort ‘waste’ from the Volcanic unit is low grade ore and will be stockpiled for processing later in the mine life. Ore sorting pre-concentration increases the mill feed gold and silver grades by 32% and 31% r ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Gold
|
Head Grade, g/t
| 0.77 |
Silver
|
Head Grade, g/t
| 47.9 |
Gold Equivalent
|
Head Grade, g/t
| 1.41 |
Reserves at December 12, 2018:
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
31.6 Mt
|
Gold
|
0.7 g/t
|
714 koz
|
Proven
|
31.6 Mt
|
Silver
|
43.5 g/t
|
44,273 koz
|
Probable
|
41.4 Mt
|
Gold
|
0.51 g/t
|
673 koz
|
Probable
|
41.4 Mt
|
Silver
|
30.7 g/t
|
40,887 koz
|
Proven & Probable
|
73.1 Mt
|
Gold
|
0.59 g/t
|
1,387 koz
|
Proven & Probable
|
73.1 Mt
|
Silver
|
36.3 g/t
|
85,159 koz
|
Measured
|
43,380,000 t
|
Gold
|
0.62 g/t
|
862 koz
|
Measured
|
43,380,000 t
|
Silver
|
36.27 g/t
|
50,590 koz
|
Measured
|
43,380,000 t
|
Gold Equivalent
|
1.14 g/t
|
1,591 koz
|
Indicated
|
80,760,000 t
|
Gold
|
0.44 g/t
|
1,145 koz
|
Indicated
|
80,760,000 t
|
Silver
|
22.67 g/t
|
58,870 koz
|
Indicated
|
80,760,000 t
|
Gold Equivalent
|
0.77 g/t
|
1,994 koz
|
Mine Management:
Job Title | Name | Profile | Ref. Date |
.......................
|
.......................
|
|
Sep 9, 2019
|
.......................
|
.......................
|
|
Sep 9, 2019
|
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Corporate Filings & Presentations:
- Subscription is required.
News:
News | Date |
Almaden Provides Update on Permitting for Ixtaca Precious Metals Project, Mexico
|
December 21, 2020
|
Almaden Closes Non-Brokered Private Placement
|
August 6, 2020
|
Almaden Announces Proposed Non-Brokered Private Placement
|
July 23, 2020
|
Almaden Closes non-brokered private placement and Files Form 20-F Documentation
|
March 27, 2020
|
Almaden Announces Proposed Non-Brokered Private Placement
|
March 10, 2020
|
Almaden Updates Stakeholders on Permitting for the Ixtaca Project, Mexico
|
October 29, 2019
|
Almaden Releases 2019 Report on Corporate Social Responsibility; Updates Permitting Process at Ixtaca
|
March 19, 2019
|
Almaden Files Feasibility Study of the Ixtaca Gold-Silver Project, Mexico
|
January 24, 2019
|
Almaden Minerals Reports 42% After-Tax IRR From Feasibility Study for the Ixtaca Precious Metals Project, Mexico
|
December 11, 2018
|
Almaden Minerals Updates Feasibility Study at Ixtaca
|
March 21, 2018
|
- Subscription is required.