Gold Recovery Methods at Jaguar’s Caeté Plant: Flowsheet & Performance

Source: Jaguar Mining Inc (2026)
Website: https://www.jaguarmining.com/assets/caete-complex

Critical Data

Overview

Jaguar Mining Inc. operates the Caeté Mining Complex in Minas Gerais, Brazil, a gold processing facility with a design capacity of 720,000 tonnes per annum (tpa) of run-of-mine (ROM) ore. Established as a cornerstone of Jaguar’s operations, the plant employs a multi-stage recovery flowsheet that integrates crushing, grinding, gravity concentration, flotation, concentrate leaching, and carbon-in-pulp (CIP) gold recovery. The significance of the Caeté Plant lies in its ability to handle complex gold ores from the Pilar and other deposits, achieving high recovery through a combination of gravity and flotation pre-concentration followed by intensive cyanidation. The process begins with a two-stage crushing circuit (jaw and cone crushers) reducing ore to -25 mm, followed by a ball mill operating in closed circuit with hydrocyclones to achieve a target grind size of 80% passing 74 µm. Free gold is recovered via a Knelson centrifugal concentrator and an Acacia reactor, while sulphide-hosted gold is floated in a series of twelve cells. The flotation concentrate is leached with cyanide and oxygen in a five-tank circuit, with gold recovered from solution by CIP and electrowinning. Tailings are treated through cycloning, thickening, and filtration for dry stacking, with a dedicated detoxification system using hydrogen peroxide and ferrous chloride to manage cyanide and arsenic. The plant employs 109 personnel and consumes key reagents including cyanide (203 t/y), liquid oxygen, and grinding media.

Key Process Stages

• Stage 1: Crushing – Ore from Pilar is trucked to the ROM stockpile and fed via grizzly to a CJ411 jaw crusher (111 kW) in open circuit. Oversize is processed by a CH440 cone crusher (223 kW) in closed circuit with a three-deck screen (75, 35, 16 mm apertures). The final crushed product is 100% passing 25 mm, conveyed to a stockpile for grinding.
• Stage 2: Grinding and Gravity Gold Recovery – The grinding circuit uses a 2,240 kW ball mill (5 m Ø x 6 m EGL) operating at up to 100 tph in closed circuit with five hydrocyclones. Overflow (80% passing 74 µm) reports to flotation; underflow (75%) feeds a Knelson centrifugal concentrator for free gold recovery. Gravity concentrate is treated in an Acacia intensive cyanidation reactor, with gold recovered by electrowinning and refined into doré bars.
• Stage 3: Flotation – A series of twelve 14.1 m³ flotation cells (three roughers, three primary scavengers, three secondary scavengers, three tertiary scavengers) produce a final gold-bearing concentrate (82-87% passing 45 µm). Rougher and primary scavenger concentrates are combined, thickened to ~40% solids, and sent to leaching. Secondary scavenger concentrate is recirculated to roughers; tertiary scavenger tails are cycloned for backfill or tailings disposal.
• Stage 4: Leaching and Carbon-in-Pulp (CIP) – The thickened flotation concentrate undergoes pre-oxidation with oxygen and lime (pH 10.0-10.5) before entering a four-tank leach circuit. Cyanide is added to dissolve gold, with oxygen sparging to enhance dissolution and reduce cyanide consumption. Slurry then flows through four CIP tanks (a fifth under construction, expected Q2 2026) where gold is adsorbed onto activated carbon. Loaded carbon is screened and sent to elution.
• Stage 5: Gold Recovery and Detoxification – Loaded carbon is eluted at ~98°C with 1.5% NaOH and 0.5% NaCN. Pregnant solution passes through electrolytic cells where gold is deposited on steel wool cathodes. The gold sludge is pressure-filtered, dried, and smelted into doré bars (80-90% Au). Spent carbon is acid-washed (5% HCl) and regenerated at 700°C. CIP tailings are filtered to 10% moisture and dry-stacked at Moita Dam. Detoxification uses hydrogen peroxide and UV ponds to reduce cyanide, followed by ferrous chloride and lime to precipitate arsenic via ferric arsenate. Effluent is settled and recycled.

Additional Interesting Data and Summary

The Caeté Plant’s technical data reveals a robust and adaptable gold recovery operation. Annual reagent consumptions include 203 tonnes of sodium cyanide, 438 tonnes of grinding media, 1,214,816 m³ of liquid oxygen, and 266,955 kg of copper sulphate, reflecting the intensive nature of the flotation and cyanidation circuits. The plant also uses 52,695 kg of hydrochloric acid for carbon washing and 46,630 kg of ferrous chloride for arsenic precipitation. Environmental management is a key focus: the detoxification system (operational since September 2020) reduces residual cyanide using hydrogen peroxide and solar UV in pre-treatment ponds, with ferrous chloride and lime precipitating arsenic as ferric arsenate. Tailings disposal has transitioned to filtered dry stacking at the Moita Dam, an exhausted open pit lined with geomembrane, with a remaining capacity of 43,000 m³ out of a licensed 360,000 m³. Flotation tailings are cycloned, with underflow used as backfill at the Pilar mine and overflow thickened and dry-stacked at RG2 E&W TSFs. Future improvements include the addition of a fifth CIP tank (expected Q2 2026), which will increase circuit capacity by 50% to 60,000 t/month of concentrate, enhancing residence time and reducing solution losses. Economically, the Caeté Plant supports a workforce of 109 employees (69 plant, 40 maintenance), with power consumption of 21,800 MWh/yr sourced from the grid and water from the Marembá do André Tunnel (520,400 m³/yr). The plant’s integration of gravity, flotation, and CIP allows it to achieve strong recoveries on a variety of ore types, while ongoing expansions and closure planning (e.g., Moita Dam transition) demonstrate Jaguar Mining’s commitment to sustainable operations. The overall significance of the Caeté Plant lies in its proven flowsheet, continuous optimization, and alignment with modern environmental standards in Minas Gerais.

Key Processes: Flotation, CIP/CIL, Cyanidation, Gravity Separation, Ball Mill, Crushing

Target Commodities: Gold, Copper