The 2022 technical report for the Grota do Cirilo Lithium Project describes feasibility- and pre-feasibility-level designs for a multi-stage spodumene concentrator complex in Brazil, with processing data based on metallurgical test work performed at SGS Canada Inc.
Article Body
The Grota do Cirilo Lithium Project is designed around a series of spodumene concentrator plants that use dense media separation (DMS) as the primary recovery method, supplemented by additional recovery of petalite from the DMS float stream. The design data for the Xuxa plant is based on feasibility-level metallurgical test work conducted at SGS Canada Inc., while the combined Barreiro and Nezinho do Chicao (NDC) concentrator designs are based on pre-feasibility-level test work performed at SGS Canada Inc. in Lakefield, Ontario. The mass balance, process design criteria, and process flow diagrams for each plant were developed from laboratory test work results.
The process plants are designed around proven DMS circuits. Ore is fed through a crushing circuit and conveyed to the DMS plant. The DMS plant receives crushed ore from a feed bin, and the material is processed through coarse and fines DMS stages. When the crushing plant is not operating, the DMS plant may be fed via front end loader from stockpiles through an emergency feed bin and feeder. In the DMS plant, crushed ore from the feed bin is transported to the DMS circuit, where the material reports to a coarse sizing screen, which screens at 4.0 mm. Additional processing includes a magnetic separator for iron removal to meet the product iron content criteria, producing a final spodumene concentrate at 6% Li2O, which is combined with petalite floats from a scavenger DMS circuit to produce an average combined concentrate. During Front-End Engineering Design (FEED), the mass balance and all technical documentation were updated to show changes in the process design.
The Xuxa plant has an operating schedule of 365 days per year, 24 hours per day, with two shifts per day for crushing and sorting and three shifts per day for the wet plant, at eight hours per shift. The Barreiro and NDC plants operate with three, eight-hour shifts for both crushing and wet plant activities, with an overall availability of 68% for crushing and 85% for the wet plant. Water recovery is achieved through a thickener, where all fines slurry streams are directed and recovered, with the process water pumped to a process water tank and recycled to the circuits.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Xuxa operating days | 365 | days per annum | Operating parameters |
| Xuxa operating hours | 24 | hours per day | Operating parameters |
| Xuxa calendar hours | 8,760 | hours | Calculated |
| Xuxa shifts (crushing & sorting) | 2 | shifts per day | Operating parameters |
| Xuxa shifts (wet plant) | 3 | shifts per day | Operating parameters |
| Shifts length | 8 | hours per shift | Operating parameters |
| Xuxa nominal ore processing rate | 1,500,000 | dry tonnes per year | Client-specified |
| Xuxa nominal ore processing rate | 1,530,612 | wet tonnes per year | Calculated |
| Xuxa wet plant operating hours | 7,446 | hours per year | Industry standard |
| Xuxa wet plant feed rate | 5,479 | dry tonnes per day | Calculated |
| Xuxa power consumption | 6.7 | MW | Process plant; additional 1.5 MW for non-process infrastructure |
| Xuxa raw water consumption | 38 | m3/hr | Nominal; additional make-up as necessary |
| Barreiro operating days | 365 | days per annum | Operating parameters |
| Barreiro operating hours | 24 | hours per day | Operating parameters |
| Barreiro shifts (crushing & wet plant) | 3 x 8 | hours | Operating parameters |
| Barreiro overall availability (crushing) | 68 | % | Operating parameters |
| Barreiro overall availability (wet plant) | 85 | % | Operating parameters |
| Barreiro total ore processing rate | 1,850,000 | dry tonnes per year | Design basis |
| Barreiro total ore processing rate | 1,888,000 | wet tonnes per year | Design basis |
| Barreiro design ore crushing rate | 390 | dry tonnes per hour | Design basis |
| Barreiro nominal ore crushing rate | 3292 | dry tonnes per hour | Weighted average |
| Barreiro nominal ore crushing rate | 298 | wet tonnes per hour | Weighted average |
| Barreiro wet plant operating hours | 5,962 / 4,744 | hours per year | Nominal / design |
| Barreiro process tailings production | 1,630,000 | dry tonnes per year | Weighted average |
| Barreiro process tailings production | 1,880,040 | wet tonnes per year | Weighted average |
| NDC total ore processing rate | 1,850,000 | dry tonnes per year | Design basis |
| NDC total ore processing rate | 1,888,000 | wet tonnes per year | Design basis |
| Combined Barreiro/NDC total ore processing rate | 3,900,000 | dry tonnes per year | Design basis |
| Combined Barreiro/NDC total ore processing rate | 4,087,200 | wet tonnes per year | Design basis |
| Combined Barreiro/NDC Li2O DMS stage recovery (spodumene) | 58.7 | % | Overall |
| Combined Barreiro/NDC Li2O global recovery (spodumene) | 50.6 | % | Overall |
| Combined Barreiro/NDC Li2O global recovery (coarse DMS, spodumene) | 34.3 | % | Overall |
| Li2O global recovery (ultrafines DMS, spodumene) | 4.2 | % | Combined |
| Li2O DMS stage recovery (petalite) | 5.9 | % | Overall |
| Li2O global recovery (combined, petalite) | 5.1 | % | Overall |
Key Process Stages
The Xuxa plant design shows a feasibility-level study based on 2019 metallurgical test work. The combined Barreiro/NDC concentrator design is based on pre-feasibility-level test work using three variability samples and a composite sample for NDC and four variability samples with a composite sample for Barreiro. The DMS circuits are the central processing units, with coarse and fines DMS stages recovering spodumene and a scavenger DMS circuit recovering petalite. The final concentrate for spodumene is targeted at 6% Li2O, with magnetic separation for iron removal.
Additional Interesting Data and Summary
The technical report notes that the DMS plant may be fed via front end loader from stockpiles through an emergency feed bin when the crushing circuit is not operating, providing operational flexibility. The process plants are designed with water recovery via thickener, with all fines slurry streams directed to the thickener and recycled to the process. Consumables include reagents and operational consumables for the crushing circuit and the DMS plant. The process design uses a proven DMS circuit approach, with the overall recovery for the combined Barreiro/NDC circuit reaching approximately 50.6% Li2O for spodumene, and an additional 5.1% Li2O recovered as petalite.
Key Processes
- Crushing circuit with jaw and cone crushers, including secondary and tertiary crushing stages
- Dense media separation (DMS) for coarse and fines fractions
- Scavenger DMS circuit for petalite recovery from the spodumene DMS float stream
- Magnetic separation for iron removal to meet product iron content criteria
- Thickener for water recovery and recycling
Source: Grota do Cirilo Lithium Project , 2022 Technical Report, 2022.
Project website: Grota do Cirilo Lithium Project, 2022 Technical Report
