This feasibility study update describes the proposed processing flowsheet for a copper-gold operation in southern Pará State, Brazil.
Report context
The technical report titled "Boa Esperança Project NI 43-101 Technical Report on Feasibility Study Update" has an effective date of 31 August 2021 and was prepared for Ero Copper Corp. The project is located in southern Pará State, Brazil. The report documents a feasibility study update, incorporating metallurgical testwork and proposed processing design.
Processing route
Overview
The proposed recovery methods are based on conventional crushing, grinding, and flotation to produce a copper concentrate. The process flow sheet includes run-of-mine ore handling and crushing, a crushed ore stockpile, ball mill grinding, flotation, concentrate regrind, and concentrate dewatering. The design also includes pyrite tailings dewatering and a pyrite concentrate pond water reclaim system.
Crushing and Grinding
The proposed process begins with run-of-mine ore handling and primary crushing, followed by a crushed ore stockpile. Grinding is performed using a ball mill circuit. Historical testwork for crushability and grindability was conducted as part of the metallurgical testing program.
Flotation
The flotation circuit includes rougher flotation, followed by open circuit cleaner flotation tests and locked-cycle flotation tests conducted as part of the testwork program. The design contemplates concentrate regrind after flotation. The report documents flotation condition tests and rougher variability flotation tests from the metallurgical testwork.
Concentrate Handling
Copper concentrate is processed through dewatering, storage, and load-out facilities. Concentrate thickening and filtration tests were performed as part of testwork. The design includes concentrate regrind prior to dewatering.
Tailings Management
The proposed design includes pyrite tailings dewatering and a pyrite concentrate pond water reclaim system. Tailings storage facilities are part of the project infrastructure. Thickening tests for final tailings and pyrite concentrate were conducted.
Pre-concentration
A pre-concentration assessment was conducted, including 2015 SGS Geosol jigging tests as part of testwork. Magnetic separation tests were also performed.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Process type | Crushing, ball mill grinding, flotation | Proposed design |
| Copper concentrate route | Regrind, dewatering, storage, load-out | Proposed design |
| Pre-concentration test | Jigging test (2015 SGS Geosol) | Testwork |
| Flotation testwork | Condition tests, rougher variability, open circuit cleaner, locked-cycle | Testwork |
| Concentrate thickening/filtration | Copper concentrate and final tailings tests | Testwork |
| Magnetic separation | Test performed | Testwork |
| Pyrite concentrate handling | Dewatering and pond water reclaim | Proposed design |
| Sampling/metallurgical lab | Included in plant design | Proposed design |
Project website: https://www.srk.com/en/projects/boa-esperan%C3%A7a-copper-cobalt-deposit
Technical qualifications
The report is a feasibility study update and does not represent detailed engineering or construction documentation. The qualified person responsible for the processing sections (sections 1.2, 1.8, 1.13, 1.16, 1.17, 1.20, 1.21, 2, 3, 13, 17, 21.1-21.1.6, 21.1.8-21.1.11, 21.2.1, 21.2.3-21.2.5, 25.5, 25.10, 25.14, 25.15, 25.17-25.17.1.1, 25.17.2-25.17.2.1, 25.18, 25.2, 25.3, 25.4, 25.6, 26 and 27) has not visited the Boa Esperança Project site. The metallurgical testwork results are from historical and feasibility study test programs, and recovery projections are based on these tests. The flowsheet remains a proposed design based on feasibility study assumptions.
Source: Boa Esperança Project NI 43-101 Technical Report on Feasibility Study Update, effective 31 August 2021, Sections 1.13, 13, 17.
