A gold washing plant or gold placer mineral processing plant is designed to extract gold from placer deposits (alluvial, eluvial, or beach sand deposits) through a series of mechanical and gravity separation processes. Below is an overview of the key components, working principles, and processes involved:
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1. Types of Gold Placer Deposits
– Alluvial Gold: Found in riverbeds and floodplains.
– Eluvial Gold: Weathered material at the base of hills.
– Beach Placers: Concentrated along shorelines.
– Bench Deposits: Ancient river terraces.
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2. Key Components of a Gold Washing Plant
# (1) Feeding System
– Hopper & Grizzly Screen: Removes large rocks before feeding material into the plant.
– Vibrating Feeder: Ensures a steady flow of material.
# (2) Scrubbing & Washing
– Trommel Screen (Rotary Scrubber): Washes and breaks up clay-bound gravels while screening out oversized r.jpg)
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– Vibrating Screen: Further classifies material into different sizes.
# (3) Gravity Separation (Core Process)
– Jig Machine: Separates heavy gold particles from lighter materials using pulsating water flow.
– Gold Centrifuge (Knelson/Falcon Concentrator): Uses centrifugal force to recover fine gold.
– Shaking Table: Refines concentrates by separating gold from other heavy minerals.
– Sluice Box (with Riffles/Mats): Traditional method where gold settles behind riffles as water flows.
# (4) Tailings Management
– Dehydration Screen/Sand Pump: Removes excess water before tailings disposal.
– Tailings Pond/Recycling System: Minimizes environmental impact.
# (5) Gold Recovery & Refining
– Mercury/Gold Amalgamation (less common due to toxicity).
– Gold Smelting Furnace (melts concentrates into doré bars).
– Electrolysis/Chemical Leaching (for high-purity refining).
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3. Processing Steps in a Placer Gold Plant
1. Excavation & Feeding → Raw material is dug and fed into the trommel.
2. Scrubbing & Screening → Clay and debris are removed; ore