Overview
Stage | Preliminary Economic Assessment |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Longhole open stoping
- Cemented rockfill
|
Mine Life | 8 years (as of Jan 1, 2014) |
The Company has maintained the Bilbao mineral concessions and title to the property in good standing and with the improved outlook for zinc, lead and silver prices, continuesto solicit interest in the Bilbao project from operating silver producers with the objective of converting an asset, in which Xtierra invested over $23 million, into cash flowing royalties in order to maximize value for shareholders. |
Source:
p. 3
Xtierra Inc., through its Mexican subsidiaries, holds a 100% interest in the Bilbao zinc-silver-lead-copper project located approximately 500km northwest of Mexico City in the southeastern part of the State of Zacatecas.
Contractors
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Summary:
The Bilbao deposit is characterised by skarn minerals (eg. hedenbergite (pyroxene), wollastonite and other calcsilicates) and can be classified as a polymetallic skarn deposit.
Base metal skarn-type deposits commonly form a continuum with Carbonate Replacement Deposits (=CRD‘) that are generally developed distally from intrusions. In Mexico such deposits are known as manto type deposits when the mineralization forms a coherent massive sulphide sheet.
The Bilbao mineralization is classic contact metamorphic skarn type developed by irregular replacement of carbonate. However, there are marked constraints on this irregularity in that the mineralization selectively replaces certain horizons in the stratigraphy of the limestone and so assumes lenticular form. Furthermore, there is a strong tendency for mineralization to occur at the granitic contact. Because the mineralization is related to fluids emanating from the (hot) granite this impinges on the mineralogical zoning away from the heat source and results in higher temperature minerals being deposited closer to the main granite contact. This has implications on primary mineralogy, especially for zinc, which in this case appears to have formed several mineral species in congruence with the above zonation. Thus at the higher temperatures prevailing close to the granite franklinite, willemite and hemimorphite have developed whereas sphalerite appears to have formed further away from the contact.
Th ........
Mining Methods
- Longhole open stoping
- Cemented rockfill
Summary:
Given the results of metallurgical testwork on the oxide and transition mineral zones, the mine plan incorporated in this study targets the extraction of the sulphide zone only. Underground mining methods will be used to access the sulphide zone located approximately 50 meters below surface, and accessed via a portal and ramp system.
The main proposed mining method is Longhole Open Stoping using downholes, while near the top of the deposit Longhole Open Stoping using upholes will be employed. Stopes will have maximum nominal dimensions of 24 metres wide by 12 metres long and a 24-metre vertical height. Longhole stopes will be backfilled with a cemented rock fill. Also, near the edges of the deposit, remnant Longhole Open Stoping with downholes will be used with no backfill placed in mined out stopes.
The main access to the underground mine will be via a main ramp from surface to the 1860 Level. The main ramp will connect from surface to all production levels in the mine, and provide a passage way for transportation of ore and waste material, personnel, materials and equipment. From the main ramp level accesses in waste at approximately 24 metre vertical intervals will be developed from the 2000 to 1860 Levels.
A pilot overcut crosscut from the footwall drift will be developed at the top of a stope from the footwall to hangingwall of the potentially economic mineralized zone. A full width and length undercut sill will be developed in initial st ........
Source:
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Flow Sheet:
Summary:
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Projected Production:
Commodity | Product | Units | Avg. Annual | LOM |
Zinc
|
Concentrate
|
kt
| 27 | 194 |
Zinc
|
Payable metal
|
M lbs
| | 157 |
Lead
|
Concentrate
|
kt
| ...... | ...... |
Lead
|
Payable metal
|
M lbs
| | ...... |
Silver
|
Payable metal
|
oz
| | ...... |
* According to 2014 study.
Reserves at April 28, 2014:
Total resources by mineral type at 3% Zn equivalent cut-off.
Category | Tonnage | Commodity | Grade |
Indicated
|
6,125,227 t
|
Zinc
|
2.31 %
|
Indicated
|
6,125,227 t
|
Lead
|
1.81 %
|
Indicated
|
6,125,227 t
|
Silver
|
65 g/t
|
Indicated
|
6,125,227 t
|
Copper
|
0.19 %
|
Indicated
|
6,125,227 t
|
Zinc Equivalent
|
7.5 %
|
Inferred
|
4,509,537 t
|
Zinc
|
1.36 %
|
Inferred
|
4,509,537 t
|
Lead
|
1.78 %
|
Inferred
|
4,509,537 t
|
Silver
|
47 g/t
|
Inferred
|
4,509,537 t
|
Copper
|
0.15 %
|
Inferred
|
4,509,537 t
|
Zinc Equivalent
|
5.73 %
|
Total Resource
|
10,634,764 t
|
Zinc
|
1.91 %
|
Total Resource
|
10,634,764 t
|
Lead
|
1.81 %
|
Total Resource
|
10,634,764 t
|
Silver
|
58 g/t
|
Total Resource
|
10,634,764 t
|
Copper
|
0.17 %
|
Total Resource
|
10,634,764 t
|
Zinc Equivalent
|
6.76 %
|
Mine Management:
Job Title | Name | Profile | Ref. Date |
.......................
|
.......................
|
|
Jan 11, 2024
|
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Staff:
Total Workforce | Year |
|
2014
|
Corporate Filings & Presentations:
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