- Mineral Processing
- Exploration and Geology
70% interest acquired from a private Chinese mining company January 2011
Located approximately 220 km southwest of Changsha, the capital city of Hunan Province, China
Baiyunpu (BYP) currently under care and maintenance
Previous operations included a ~500 tpd ramp-supported, underground mine and a sulphide flotation plant
Produced lead, zinc, and gold-bearing pyrite concentrates sold to smelters in the province. From 2006 to 2014, the mine produced:
1,403 t of lead at a recovered grade of 0.46%
8,936 t of zinc at a recovered grade of 2.9%
25,335 oz of gold at a recovered grade of 3.56 g/t
Production was suspended due to required capital upgrades to sustain its ongoing production and unfavourable market conditions
Silvercorp holds the surface land use rights over the 3.67 km2 Mining License area until 2063. Previous Mining License, for lead and zinc mining only, has expired. The Company is in the process of applying for a new mining permit for a gold-only operation. The process has taken longer than expected due to a provincial-wide rezoning of environmental and ecological areas. The BYP mining permit is outside of these areas. In parallel, the Company continues to explore various options for this asset.
BYP - Introduction
The development of future gold operations at BYP can be fast-tracked by leveraging existing production infrastructure, including the substantially completed 265 m long shaft/headframe with a hoisting capacity of 1,000 tpd.
BYP - Mining
A gold-only operation at BYP requires the construction of a new processing plant. The existing (idle) 500 tpd mill, which previously processed mineralization mined from the lead-zinc and gold zones, will be dismantled.
BYP - Mineral Processing
Most Recent Work/Highlights
13,335 m of drilling in 64 diamond drill holes from 2011 to 2014 supported an updated mineral resources estimate in May 2019 (effective November 30, 2018).
Surface drilling (3 rigs) aimed to extend known mineralization, improve geological understanding, and grow gold and lead-zinc resource base by identifying new zones along strike and down dip
Underground drilling (4 rigs) aimed to improve geological understanding of the existing gold zones, test the margins of these zones and explore for extensions
BYP Mineral Resources Estimate as of 30 November, 2018
1. The Statement of Estimates of Mineral Resources has been compiled under direction of Mr. Bob Dennis, who is a fulltime employee of RPM and Member of the Australian Institute of Geoscientists and have sufficient experience that is relevant to the style of mineralization and type of deposit under consideration and to the activity that they have undertaken to qualify as a Qualified Person as defined in the CIM Standards of Disclosure.
2. All Mineral Resources figures reported in the table above represent estimates based on drilling completed up to 30th Nov 2018. Mineral Resource estimates are not precise calculations, being dependent on the interpretation of limited information on the location, shape and continuity of the occurrence and on the available sampling results. The totals contained in the above table have been rounded to reflect the relative uncertainty of the estimate. Rounding may cause some computational discrepancies.
3. Silvercorp owns 70% equity interest of BYP Au-Pb-Zn Project whose whole resource is reported as above tables.
4. Pb Equivalent (PbEq) calculated using long term "Energy & Metals Consensus Forecasts" January, 2019 average of USD$1,490/t for Au, USD$2,280/t for Pb, USD$2,760/t for Zn (increasing 20% by prediction) and processing recovery of 87.41% Au, 85.87% Pb and 92.71% Zn based on 2018 BYP development and utilization plan report. Based on grades and contained metal for Au, Pb and Zn, it is assumed that all commodities have reasonable potential to be economically extractable. a. The formulas used for equivalent grade is: PbEq= Pb + Zn*1.3069 + Au*2.1386 b. The formula used for Au ounces is: Au Oz = [Tonnage x Au grade (g/t)]/31.1035.
5. Mineral Resources are reported on a dry in-situ basis.
6. The overlapped areas were reported inside lead and zinc resource table based on Pbeq cut-off.
7. Mineral Resources are reported at a 1.6 g/t Au cut-off and 3% Pb equivalent cut-off. Cut-off parameters were selected based on an RPM internal cut-off calculator in which the gold price of USD$1,490 per ounce, Lead price of USD$2,280/t and Zinc price of USD$2,760/t, inflated to 120% of prices from "Energy & Metals Consensus Forecasts", to reflect long term price movements were applied, and the mining cost of USD$35 per ton, processing cost of USD$13.3 per ton milled and processing recovery of 87.41% Au, 85.87% Pb and 92.71% Zn based on 2018 BYP development and utilization plan report were applied.
8. No mining license depth limit was applied for the Mineral Resource reporting. Any new mining license will introduce a depth limit for Mineral Resource reporting.
9. The Mineral Resources referred to above, have not been subject to detailed economic analysis and therefore, have not been demonstrated to have actual economic viability.
High-grade gold intercepts at the BYP mine:
ZK16-107 intersected a 69.50 m interval grading 5.00 g/t gold from surface, including a 7.21 m interval grading 10.68 g/t gold.
ZK17-101 intersected a 47.29 m interval grading 4.50 g/t gold from surface, including a 5.34 m interval grading 8.72 g/t gold.
ZK17-105 intersected a 46.67 m interval grading 4.61 g/t gold from surface, including a 10.70 m interval grading 9.46 g/t gold.
Mineralization in the gold and lead-zinc areas remains open along strike and down dip, and the greater property package remains prospective for new discoveries. However, Silvercorp has no plan to explore BYP at the moment.
The BYP property is located at the contact between the east to west-striking Baimashan-Longshan uplift belt and the NE-trending Chengbu-Taojiang tectonic belt, within the southwest-dipping end of the regional Dachengshan anticlinorium (dome structure). Bedrock in the property area consists predominantly of Devonian clastic and carbonate rocks. Precambrian and Cambrian rocks occur at the eastern margin of the property and are unconformably overlain by a Middle Devonian sedimentary sequence. Faults and folds of variable attitudes are well developed and control the distribution of gold, lead and zinc mineralization.
To date, 30 lead-zinc and 11 gold zones have been identified. The mineralized zones occur in two sub-areas:
Haitangling, on the northwest portion of the property, contains lead-zinc zones 6, 7 and 30.
Baiyunchong, on the south portion of the property, contains all the gold zones and the other 27 lead-zinc zones.
Lead and zinc zones occur as stratiform and lenticular bodies in Devonian carbonate rocks, which overlie the host gold sequence. The occurrence and size of individual zones are controlled and affected by pre-mineralization and post-mineralization faults and folds. Lead and zinc mineralization is closely associated with second-order fractures and fractured zones in the hanging walls of major faults. Major metallic minerals in the lead-zinc zones include pyrite, sphalerite, galena and boulangerite. Chalcopyrite and clinohedrite occur as accessory minerals. Metallic minerals are unevenly distributed as disseminated and fissure-filling mineralization.
Gold zones occur as stratiform or lenticular bodies in fractured clastic rocks in the lower portion of the Middle Devonian sedimentary sequence. The distribution of gold mineralization is structurally controlled by two major NE-trending faults, F3 and F5. Fine-grained (<1 mm) pyrite is the major host mineral for gold and is commonly unevenly distributed as veinlets or disseminations. Metallic minerals consist of native gold, pyrite, arsenopyrite, sphalerite, galena, siderite, tenorite, and rare stibnite. Eleven gold zones have been identified to date at elevations from 40 m to 300 m above sea level. Individual zones range from 50 m to 600 m in length and 2 m to 50 m in thickness.