The Preliminary Economic Assessment describes a proposed 1,500 t/d concentrator using crushing, grinding, bulk and zinc flotation, and gravity gold recovery to produce lead-silver, zinc, and coarse gold concentrates.
Report context
This article is drawn from the Tangana Project Preliminary Economic Assessment dated April 2023. The report presents a proposed processing plant design for the Tangana project, with process design criteria largely assumed based on experience at the existing Nueva Recuperada concentrator located 22 km south of the future Tangana site, and on experience with operations treating similar mineralization at a similar scale.
Processing route
Crushing and ore preparation
Run-of-mine material will be reclaimed from a ROM bin using a vibrating grizzly feeder. Process water will be added at a trommel to remove clays, with the fine material and water flowing directly to the mill pump box. Coarse material will be fed to a primary jaw crusher via conveyor, with a metal detector fitted to protect downstream equipment. Primary crusher discharge will report to a vibrating screen; oversize will feed a secondary cone crusher, with screen undersize collected and returned. Secondary crusher product will report to a fine feed bin.
The milling feed bin will discharge onto conveyors feeding the rod mill. Surplus material will overflow to a crushed material stockpile, which can be reclaimed if the crushing area is not functioning. The nominal milling feed bin capacity will be calculated for two days of continuous milling operation while the crushing area is down for maintenance.
Grinding, classification, and gold recovery
The primary grind size feeding flotation will be P80 = 90 µm. The rod mill will reduce material from 45 mm to 2.2 mm and will be provided with a screen to remove metallic materials. Rod mill product will discharge into the mill pump box, which will also receive fines and water from the trommel. The combined material will feed a cyclone battery for classification at P80 = 74 µm. The coarse fraction will return to the ball mill, which will reduce material from 3.3 mm to 75 µm, with product size controlled by a particle size analyzer.
A gravity bowl concentrator will scalp coarse gold from the grinding circuit. A shaking table will clean the bowl concentrate to commercial quality, after which it will be stored in a secure area until shipment. Gravity tailings will be directed to the flotation process.
Flotation process
The bulk flotation circuit will process material to recover copper, lead, and silver, comprising rougher, cleaner, and scavenger stages. The rougher stage involves conditioning grinding circuit product with reagents followed by flotation. Rougher concentrates will transfer to the cleaner stage for further concentration, then to the scavenger flotation cell. Final concentrate from the scavenger stage will be thickened and filtered.
The zinc flotation circuit involves multiple stages of activation, conditioning, rougher, cleaner, and scavenger flotation. Bulk tailings will be subjected to activation using copper sulfate to activate sphalerite minerals. The conditioned material will undergo rougher flotation. Rougher concentrate will be reground to P80 = 54 µm to improve liberation. Reground concentrate will then be subjected to cleaner flotation to produce a final concentrate. Tails from cleaner flotation will be subjected to scavenger flotation, with concentrate combined with rougher concentrate for further cleaning. Flotation circuit control will be aided by an inline analyzer.
Concentrate dewatering
The plant will produce three concentrates: a lead-silver concentrate anticipated to assay 55% Pb and between 51 and 99 oz/t Ag, a zinc concentrate anticipated to assay 52% Zn, and a coarse gold concentrate that will be sold to a third party refinery. Concentrates from flotation will be thickened using a high-rate thickener to 60-70% solids, then filtered using a filter press. Filter cake will be stored in a covered storage area. Overflow and filtered water will be recycled. Concentrates will be loaded onto trucks by front-end loader for transport.
Tailings dewatering and disposal
Tailings from the zinc scavenging flotation bank will feed a tailings thickener to be dewatered to about 57% solids. Thickener underflow will report to a tailings filter where 12% moisture will be achieved by pressure filtration. Disc filters will use fresh water. Dry tailings will be transferred to a tailings storage facility or used as underground mine backfill. Thickener overflow and filtering water will be recycled.
Utilities and consumables
Installed power requirement is estimated at 3,015 kW. The incoming power line will feed the main electrical substation from the Peruvian national grid, with emergency diesel generators for critical standby instances.
Two potential fresh water sources have been considered: rainfall and runoff courses, and underground mine dewatering. Borehole wells could also be a source. It has been assumed that 1.9 m³/t of water will be required for the process. Dewatering water from the mine at approximately 20 l/s (72 m³/h) will mainly be used for mine operation, with an additional 67 m³/h makeup water needed for the processing plant.
Major reagents include lime for pH control, zinc sulphate and sodium cyanide as depressants, copper sulphate as a zinc activator, MIBC as frother, and collectors including sodium isopropyl xanthate, potassium amyl xanthate, thionocarbamate, Aerophine, and dithiophosphate. Steel rods and balls for grinding and flocculant for thickening are also required. Consumables estimation is based on the current operation at the existing Nueva Recuperada process plant.
Key reported parameters
| Classification | Description | Value | Units | Data Source |
|---|---|---|---|---|
| Feed characteristics | Processing rate | 1,500 | t/d | Design |
| Feed characteristics | Head grade Ag | 2.37 | oz/t | Existing plant data |
| Feed characteristics | Head grade Pb | 1.47 | % | Existing plant data |
| Feed characteristics | Head grade Zn | 1.48 | % | Existing plant data |
| Feed characteristics | ROM moisture | 3 | % | Existing plant data |
| Feed characteristics | Clay in ROM | <5 | % | Client estimation |
| Feed characteristics | Abrasion index | 0.3 | g | Estimated |
| Feed characteristics | Wi rod mill | 22 | kWh/t | Estimation from existing plant |
| Feed characteristics | Wi ball mill | 17 | kWh/t | Estimation from existing plant |
| Feed characteristics | Wi crushing | 18 | kWh/t | Estimation from existing plant |
| Feed characteristics | SG ROM | 2.74 | g/cm³ | Existing plant data |
| Product specifications | Ag grade in Pb concentrate | 53 | oz/t | Existing plant data |
| Product specifications | Pb grade in Pb concentrate | 55 | % | Existing plant data |
| Product specifications | Zn grade in Zn concentrate | 52 | % | Existing plant data |
| Grinding | Primary grind size (flotation feed) | P80 = 90 | µm | Design |
| Grinding | Classification size | P80 = 74 | µm | Design |
| Grinding | Zinc regrind size | P80 = 54 | µm | Design |
| Operations | Operating hours per shift | 12 | hours | Existing plant data |
| Operations | Operating days per year | 365 | days | Existing plant data |
| Operations | Shifts at plant | 2 | shifts | Existing plant data |
| Operations | Availability crushing area | 85 | % | Estimated |
| Operations | Availability rest of plant | 90 | % | Estimated |
| Energy | Total installed power | 3,015 | kW | Design |
| Water | Process water requirement | 1.9 | m³/t | Assumed |
| Water | Mine dewatering flow | ~20 | l/s | Assumed |
| Water | Additional makeup water needed | 67 | m³/h | Assumed |
Project website: https://www.silverxmining.com/projects/production/tangana-mining-unit/
Technical qualifications
The report states that much of the process design criteria have been assumed, based on experience at the existing Nueva Recuperada concentrator and on experience with operations treating similar mineralization at a similar scale. The plant has been designed on a fit-for-purpose basis considering a project life of about 15 years, with no consideration or allowance for any expansion. The report notes it has been prepared based on assumed information and limited metallurgical testwork. For water systems, only high-level evaluations have been made, and the report recommends quality testing of different sources for future studies to reduce processing risk in terms of metal recovery and concentrate grades.
The report provides specific recommendations before completing a prefeasibility study, including obtaining representative core samples for mineralogical and metallurgical testing for the main mineral types, optimizing the process with respect to flowsheet and equipment sizing, evaluating geometallurgical variability, validating the process flowsheet using bulk pilot testing at the Nueva Recuperada plant, and determining engineering design criteria through testwork for materials handling, tailings management, and water management.
Source: SilverX: Tangana Project, Preliminary Economic Assessment, April 2023, Sections 17.1-17.6.
Consolidated report summaries
The following former standalone pages about this operation were consolidated here on October 25, 2026. They are retained for source traceability; dates and figures reflect each report’s own effective date and may be superseded by the current information above.
NI 43-101 Preliminary Economic Assessment for the Tangana Mining Project and Plata Mining Project, Nueva Recuperada Project
This report details the process design for two concentrator plants,an expansion of the existing Nueva Recuperada plant to 1,500 t/d and a new 1,500 t/d Tangana plant,based on historical operating data, existing plant experience, and design assumptions.
Report context
This Preliminary Economic Assessment (PEA) for the Tangana and Plata Mining Projects, Nueva Recuperada Project, describes recovery methods for two mineral processing plants. The existing Nueva Recuperada concentrator, located 22 km north of the proposed Tangana plant site, currently operates at a nominal capacity of 600 t/d treating copper, lead, zinc, and silver minerals from the Tangana, Maria Luz, Positivas, San Antonio, and Pucapunta mines. The report presents a proposed expansion of the Nueva Recuperada plant to 1,500 t/d and a new 1,500 t/d Tangana concentrator, using process design criteria established from operational experience, historical production data from 1963–2013, and experience with similar polymetallic operations.
Processing route
Nueva Recuperada plant,proposed expansion to 1,500 t/d
The proposed processing route would begin with primary crushing using a TRIO 20" x 36" jaw crusher preceded by a vibrating grizzly. Crushed material would report to a fines hopper before feeding a new 16'x6' SAG mill operating as primary grinding equipment, reducing material from F80 3/4" to P80 2.0 mm. A trommel at the SAG mill discharge would separate material by size, with discharge feeding a battery of cyclones for classification. The secondary grinding circuit would comprise four ball mills: two existing mills (6'x6' and 6'x4.5') and two new mills (6'x12' and 6'x6'). Cyclone underflow would return to the secondary grinding circuit, while cyclone overflow at P80 150 µm would report to flotation.
The flotation circuit would be divided into three sequential stages: bulk flotation, selective flotation, and zinc flotation. The bulk flotation circuit would include two rougher stages, two scavenger stages, and a cleaning circuit with two stages in parallel (cleaner IA and cleaner IB). The bulk concentrate would be thickened and filtered for sale. Tailings from the second scavenger stage would be conditioned prior to zinc flotation. The zinc flotation circuit would operate with two sequential rougher stages, two cleaning stages, and three consecutive scavenger stages. The final zinc concentrate from the second cleaning stage would be thickened and filtered.
Concentrate thickening and filtration would leverage existing infrastructure, complemented by additional equipment. The tailings treatment system would maintain the current configuration, requiring only operational adjustments and improved pumping capacity. The plant would produce two concentrates: a bulk Cu-Pb-Ag concentrate and a zinc concentrate.
Tangana plant,proposed new 1,500 t/d concentrator
The proposed Tangana processing route would begin with primary jaw crushing followed by secondary screening and cone crushing. Material would be reclaimed from a RoM bin using a vibrating grizzly feeder, passing to a trommel where process water would be added to remove clays. Fine material and water would flow directly to the mill pump box. Coarse material would be fed to the primary crusher, with crushed material reporting to a vibrating screen. Screen oversize would feed the secondary crusher, with product reporting to a fine feed bin.
Primary grinding would be performed by a rod mill reducing material from 45 mm to 2.2 mm, followed by ball mill secondary grinding in closed circuit with hydrocyclone classification to achieve P80 74 µm. A gravity bowl concentrator would scalp coarse gold from a fraction of the cyclone underflow, with concentrate cleaned on a shaking table to commercial quality. Gravity tailings would be directed to flotation.
The bulk flotation circuit would include rougher, cleaner, and scavenger stages to recover copper, lead, and silver. The zinc flotation circuit would involve activation with copper sulfate, conditioning, rougher flotation, regrind to P80 54 µm, cleaner flotation, and scavenger flotation to maximize sphalerite recovery. Flotation circuit control would be aided by an inline analyzer.
Concentrate dewatering would use high-rate thickening followed by filter pressing to produce filter cake at 6% moisture for both bulk and zinc concentrates. Tailings would be thickened to approximately 57% solids, then filtered to 12% moisture for disposal in a subaerial tailings storage facility or as underground mine backfill. Process water would be recycled. The plant would produce three concentrates: a lead-silver concentrate (anticipated 55% Pb, 51–99 oz/t Ag), a zinc concentrate (anticipated 52% Zn), and a coarse gold concentrate for third-party refining.
Key reported parameters
| Parameter | Nueva Recuperada (proposed expansion) | Tangana (proposed new plant) | Basis |
|---|---|---|---|
| Nominal processing rate | 1,500 t/d | 1,500 t/d | Proposed design |
| Current operating rate | 600 t/d | , | Historical operating data |
| Annual ROM production | 433,721 t/year | 499,950 t/year | Customer estimate |
| ROM D80 | 140 mm | 900 mm | Typical (Nuva Recuperada); typical (Tangana) |
| ROM D100 | 300 mm | 1,000 mm | Typical |
| SG ROM | 2.74 g/cm³ | 2.74 g/cm³ | Existing plant data |
| Abrasion index (A) | 0.3 g | 0.3 g | Estimated |
| Clay in ROM | <5% | <5% | Customer estimate |
| Wi rod mill | 16 kWh/t | 22 kWh/t | Typical value range (Nuva Recuperada); estimation from existing plant (Tangana) |
| Wi ball mill | 14–18 kWh/t | 17 kWh/t | Typical value range (Nuva Recuperada); estimation from existing plant (Tangana) |
| Wi crushing | 18 kWh/t | 18 kWh/t | Typical value range (Nuva Recuperada); estimation from existing plant (Tangana) |
| Feed moisture | 3% | , | Existing plant data |
| Bulk density Pb concentrate | 2.9 t/m³ | 2.9 t/m³ | Estimate of existing plant department |
| Bulk density Zn concentrate | 2.7 t/m³ | 2.7 t/m³ | Estimate of existing plant department |
| Bulk density filtered tailings | 2.3 t/m³ | 2.3 t/m³ | Estimated |
| Tailings moisture | 12% | 12% | Typical |
| Pb concentrate moisture | 6% | 6% | Typical |
| Zn concentrate moisture | 6% | 6% | Typical |
| Operating hours per shift | 12 h | 12 h | Existing plant data |
| Operating days per year | 365 days | 1 day | Existing plant data |
| Crushing area availability | 85% | 85% | Estimated |
| Availability rest of plant | 90% | 90% | Estimated |
| Installed power | 2,770 kW | 3,015 kW | Proposed design |
| Annual power consumption | 13,220,936 kWh | 14,239,479 kWh | Proposed design calculation |
| Head grade Ag (Tangana feed) | , | 2.37 oz/t | Existing plant data |
| Head grade Pb (Tangana feed) | , | 1.47% | Existing plant data |
| Head grade Zn (Tangana feed) | , | 1.48% | Existing plant data |
| Ag grade in Pb concentrate (Tangana) | , | 53 oz/t | Existing plant data |
Project website: https://www.silverxmining.com/projects/nueva-recuperada-silver-district-2/
Technical qualifications
This Preliminary Economic Assessment includes process design criteria that are largely assumed based on operational experience at the existing Nueva Recuperada concentrator, historical production data from 1963–2013, and experience with similar polymetallic operations. The Tangana plant design is fit-for-purpose with a project life of about 15 years and includes no consideration or allowance for future expansion. For the Tangana plant, much of the process design criteria have been assumed, and the report notes that only high-level evaluations have been made for water sourcing, recommending that quality testing of different sources be performed in future studies to reduce processing risk in terms of metal recovery and concentrate grades. The report does not provide testwork results for the proposed flowsheets, nor does it present detailed flotation performance data, metallurgical balances, or economic parameters.
Source: NI 43-101 Preliminary Economic Assessment for the Tangana Mining Project and Plata Mining Project, Nueva Recuperada Project, Recovery Methods section.
