This prefeasibility study outlines a proposed integrated hydrometallurgical process for treating limonite and saprolite ores from the Agata nickel laterite deposit.
Report context
The 2011 Technical Report for the Agata Nickel Project describes the process plant and associated facilities proposed at a prefeasibility study (PFS) level. Engineering deliverables produced for the study include Process Design Criteria, Process Flow Diagrams (PFDs), Mass and Energy Balance, Equipment List and Layout Drawings. The process flowsheets were developed from the results of high pressure acid leach tests and atmospheric leach tests on composites and individual ore types, the results of settling tests for ore preparation and leach residues, and Ausenco and BWHC's experience with other similar nickel laterite projects.
Processing route
Ore feed and stockpiling
Ore for the project is sourced from the Agata nickel laterite deposit. The laterite profile consists of limonite and saprolite zones. The limonite zone is characteristically iron oxide-rich, with predominant minerals hematite, goethite and clays, and moderate nickel content (<1%). The limonite overlies the saprolite zone, which is less oxidised and magnesium-rich with slightly higher nickel content. Limonite and saprolite ore will be mined and stockpiled separately at the processing facility at Tagpangahoy, in Butuan Bay. Saprolite ore is stockpiled according to magnesium content (low, medium, high) and is processed in batches in the saprolite ore preparation circuit.
Proposed three-circuit leach design
The proposed processing route consists of a high pressure acid leach (HPAL) circuit and parallel atmospheric leach (AL) circuit. Limonite and low magnesium ore will be treated by conventional HPAL. Medium magnesium saprolite ore will be treated by a parallel AL circuit. The combined discharge of the HPAL and AL circuits will then be processed in a Saprolite Neutralisation (SN) circuit followed by counter-current decantation and sections to neutralise excess acid and precipitate iron and aluminium. The SN circuit will involve pre-neutralisation of residual free acid in the combined leach discharge streams using the balance of saprolite ore, consuming much of the free acid while recovering additional nickel and cobalt values.
Ore preparation
Limonite ore, containing mainly fines, requires scrubbing of clay material prior to screening. Scrubbing testwork at Ammtec showed some magnesium rejection and hence nickel upgrade in the product. Clay composites were difficult to break up in the laboratory scrubbing process. Saprolite ore contains a rock component and is processed through a single stage SAG mill. Physical testwork data on ore was limited; comminution circuit design was based on criteria for similar ore preparation processes.
Atmospheric leaching and saprolite neutralisation testwork
The concept of saprolite neutralisation was first established in testwork conducted on Philippine laterite ores in 1998, with recovery of 60–65% of nickel and cobalt contained in high magnesium saprolite ore. Bench-scale testwork at SGS using Agata saprolite ore demonstrated recoveries of 75-77% for nickel and 75% for cobalt are achievable.
Metal recovery
Metal recovery will be by a two-stage mixed hydroxide precipitate (MHP) circuit similar to that operated at the Cawse Nickel Project in Western Australia and at Ravensthorpe Nickel Operation. The product is a filter cake containing nickel and cobalt metal in the form of a mixed hydroxide, bagged and containerised for onward shipment and export. Mixed hydroxide filter cake moisture level is expected to be 40%.
Key design basis and assumptions
All processing from ore preparation to MHP packaging, residue discharge and the sulphuric acid plant will operate on a continuous basis of 24 hours per day, 7 days per week. Allowing for downtime, long term availability is expected to be 87%, giving an operating time of 7,600 hours equivalent to a total plant throughput of 232 tonnes per hour. Most major process equipment is sized with a 15% design allowance. Exceptions include ore preparation, limestone and lime facilities with 33% design allowance, and the autoclave based on a direct 30 minutes residence time.
Autoclave throughput is based on 30% solids in the autoclave feed slurry after direct steam heating. As of August 2011, ore characterisation and scoping level iron/aluminium removal and mixed hydroxide precipitation tests were being performed by SGS Lakefield; results were not available for the PFS. Design criteria for the Fe/Al removal circuit are based on the Ramu Nickel Project pilot plant data. Design criteria for the precipitation circuit are largely based on the Ravensthorpe MHP circuit. Design criteria for the final neutralisation circuit are based on the Gladstone Pacific Nickel Limited Project testwork on manganese removal.
Key reported parameters
| Parameter | Unit | Design / Assumption Value | Basis |
|---|---|---|---|
| Ore Feed to Plant | |||
| HPAL (Limonite + Low Mg Saprolite) | Mt/y (dry) | 1.0 | Design basis |
| AL (Medium Mg Saprolite) | Mt/y (dry) | 0.4 | Design basis |
| SN (High Mg Saprolite) | Mt/y (dry) | 0.4 | Design basis |
| Total ore feed | Mt/y (dry) | 1.8 | Design basis |
| Overall Recovery | |||
| Nickel | % | 89.3 | Design basis |
| Cobalt | % | 91.1 | Design basis |
| Product | |||
| Mixed Hydroxide Precipitate (wet) | kt/y | 78 | Design basis |
| Mixed Hydroxide Precipitate (dry) | kt/y | 47 | Design basis |
| Contained Nickel in MHP | kt/y (dry) | 18 | Design basis |
| Contained Cobalt in MHP | kt/y (dry) | 0.95 | Design basis |
| HPAL Design Assumptions | |||
| Autoclave residence time | min | 30 | Design assumption |
| Temperature | °C | 255 | Design assumption |
| Nickel extraction | % | 97.5 | Design assumption |
| Cobalt extraction | % | 97.5 | Design assumption |
| Acid addition | kg/t ore | 454 | METSIM calculation |
| Terminal sulphuric acid concentration | g/L | 50 | Design assumption |
| Atmospheric Leaching Design Assumptions | |||
| Nickel extraction | % | 98.5 | Design assumption |
| Cobalt extraction | % | 92 | Design assumption |
| Acid consumption | kg/t ore | 1022 | METSIM calculation |
| Terminal acid concentration | g/L | 30 | Design assumption |
| Saprolite Neutralisation | |||
| Saprolite nickel dissolution | % | 77 | Testwork at SGS |
| Saprolite cobalt dissolution | % | 75 | Testwork at SGS |
| Terminal acid concentration | g/L | 12.3 | Design assumption |
| Mixed Hydroxide Precipitation | |||
| Precipitant | , | Magnesia | Design basis |
| MHP Stage 1 nickel precipitation | % | 95 | Design assumption |
| MHP Stage 1 cobalt precipitation | % | 97 | Design assumption |
| MHP overall nickel recovery | % | 99.8 | Design assumption |
| MHP overall cobalt recovery | % | 99.4 | Design assumption |
| Product Moisture | % | 40 | Design assumption |
| Long term plant availability | % | 87 | Design assumption |
| Operating hours | h/y | 7,600 | Design assumption |
| Plant throughput | t/h | 232 | Design assumption |
Project website: https://tvird.com.ph/agata-nickel/
Technical qualifications
The design criteria for the Fe/Al removal circuit are based on the Ramu Nickel Project pilot plant data rather than Agata-specific testwork. The design criteria for the precipitation circuit are largely based on the Ravensthorpe MHP circuit. The design criteria for the final neutralisation circuit are based on the Gladstone Pacific Nickel Limited Project testwork on manganese removal. As of August 2011, ore characterisation and scoping level iron/aluminium removal and mixed hydroxide precipitation tests were being performed by SGS Lakefield; the results were not available for the PFS. The plant site location is considered sub-optimal due to poor geotechnical conditions and mountainous terrain resulting in significant risk of land slip failures and high earthworks costs. The ore preparation scrubbing and grinding design should be re-evaluated following a metallurgical testwork programme. Higher recoveries than the PFS assumptions may be possible for saprolite nickel dissolution; ongoing testwork on the Agata ores may improve upon the PFS assumptions.
Source: Agata Nickel Project , 2011 Technical Report, Section 17 Recovery Methods
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.
Mindoro Resources Ltd — Agata Nickel Laterite Study
Mindoro Resources Ltd — Agata Nickel Laterite Study
| Company | Mindoro Resources Ltd |
| Date | Unknown |
| Commodities | Nickel |
| Status | Development |
| Consultant | Reid Resource Consulting Pty Ltd |
Executive Summary
This technical report section outlines the proposed recovery methods for the Agata nickel laterite project. A flowsheet has been developed for thermal upgrading, with design and costing completed. The study includes projected volumes and costs for consumables such as diesel, coal, fresh water, and maintenance materials.
However, the nature of this study did not include quantification of suitable feedstock for thermal upgrading. It also did not attempt to establish whether the samples tested were representative of the Agata nickel laterite deposit. These critical matters are expected to be addressed in the subsequent Pre-Feasibility Study (PFS) once the preferred products for sale are clarified.
The proposed flowsheet is generically suitable for thermal upgrading, providing a foundational design for future cost estimation and operational planning.
Website: https://www.irw-press.com/en/news/mindoro-resources-ltd-updated-resource-estimate-released-for-agata-north-nickel-laterite-project.html?isin=CA6029131050
Report Date: Unknown
Region:
Project Status: Development
Commodity: Nickel
Throughput:
Mine Life:
Mine Type:
Ore type:
Agata North Deposit Project — 2013 Technical Report
This report presents the proposed processing route, historical testwork, and design parameters for the direct shipping of high iron limonite ore from the Agata North nickel laterite deposit.
Report context
The Technical Report for the Agata North Nickel Laterite DSO Project, Mindanao, Philippines, effective 30 August 2013, was prepared for TVI Resource Development (Phils) Inc. The project includes the development, mining, and direct shipping of high iron limonite ore at the Agata North nickel laterite deposit in the Surigao mining district of Northern Mindanao. This article summarises the mineral processing, metallurgical testing, recovery methods, and supporting infrastructure as described in the original report.
Processing route
Mineral processing and metallurgical testing
Section 13 of the report covers mineral processing and metallurgical testing, which provided the basis for the proposed direct shipping operation. No further detail is available in the supplied evidence.
Recovery methods
The recovery methods described in Section 17 are based on direct shipping operations, meaning no complex on-site processing plant is proposed. The ore is intended to be excavated, stockpiled, dried, and hauled directly to a port loading facility for shipment.
Port loading facility
The port loading facility is central to the recovery method. Section 17.2 describes the facility, with design basis (Section 17.3) and design concepts (Section 17.4). The location is given in Section 17.5, and design criteria are listed in Section 17.6. The facility is designed to handle the direct shipping of limonite ore without further processing.
Assay laboratory
Section 17.8 covers the assay laboratory, with the design basis provided in Section 17.9. The laboratory supports grade control and quality assurance for the direct shipping product.
Buildings
Section 17.10 lists the buildings required for the project, though specific details are not available in the supplied evidence.
Power, water, and utilities
Section 17.11 covers power, water, and utilities for the proposed operations.
Mining method
Section 16 describes the mining method. Site preparation is covered in Section 16.2. Grade control (Section 16.3) will guide excavation and haulage (Section 16.4). Ore stockpiling and drying (Section 16.5) precedes road sheeting (Section 16.7) and ore haulage (Section 16.9). Topsoil and overburden disposal (Section 16.6) and drainage and sediment control (Section 16.10) are included. Fleet selection is given in Section 16.8. Environment and rehabilitation (Section 16.11) are part of the mine plan.
Key reported parameters
| Parameter | Value | Unit | Basis |
|---|---|---|---|
| Deposit type | Nickel laterite (high iron limonite) | , | Geological interpretation |
| Mining method | Open pit with direct shipping | , | Proposed design |
| Ore handling | Excavation, stockpiling, drying, haulage | , | Proposed design |
| Processing | Direct shipping , no on-site processing plant | , | Proposed design |
| Product | High iron limonite ore | , | Project definition |
| Port facility | Designed for direct ore loading | , | Proposed design |
| Assay laboratory | On-site for grade control | , | Proposed design |
| Supporting infrastructure | Buildings, power, water, utilities | , | Proposed design |
Project website: https://tvird.com.ph/agata-nickel-laterite-dso/
Technical qualifications
The technical report was prepared by independent qualified persons including a geological consultant, a mining consultant, and a director of a geological consultancy. The report is based on a proposed direct shipping operation and does not include detailed flowsheet design, testwork results, or performance data beyond what is summarised in the original sections. Historical operating data for the proposed facilities are not available in the report. The mineral processing and metallurgical testing section (Section 13) is referenced but not detailed in the supplied evidence. No economic analysis, ownership details, current status, or project links are provided in the original processing sections.
Source: Technical Report for the Agata North Nickel Laterite DSO Project, Mindanao, Philippines, effective 30 August 2013, Sections 13, 16, and 17.
