A wash plant is a materials-handling system first
Alluvial gold may already be liberated, but that does not make the flowsheet automatic. The plant still has to release particles from clay, reject uncontrolled oversize, classify the useful fractions and maintain a steady water and solids balance.
The first design question is therefore not “Which concentrator should I buy?” It is “What prevents the gold from reaching a concentrator in a recoverable condition?”
Free-washing material and sticky clay need different routes
Free-washing gravel may need controlled feeding, screening and staged gravity recovery. Sticky clay can require longer retention, more attrition and careful management of slimes. Adding more water alone does not always solve disaggregation, and aggressive washing can create excessive fine material that becomes difficult to recover or settle.
Representative bulk samples and simple size-by-size observations are often more useful than a single head-grade number. The test program should identify where the gold reports, what proportion is visually liberated and which size fractions carry the losses.
Design around operating reality
A practical route also accounts for seasonal water, generator capacity, excavator feeding, operator skill, spare-parts access and tailings placement. Modular equipment is valuable only when the modules form a balanced circuit.
Initial online guidance can define the likely route and missing data. Final equipment selection should follow representative material testing and confirmation of site conditions.
Typical process logic
- 01
Feed preparation
Control oversize rock and deliver a stable feed without crushing naturally liberated gold unnecessarily.
- 02
Washing and disaggregation
Break down clay-bound material so valuable particles can reach the classification and recovery stages.
- 03
Size classification
Split the feed into ranges that can be treated efficiently instead of forcing one separator to handle every particle size.
- 04
Primary gravity recovery
Recover the bulk of liberated gold with equipment selected for the actual feed size and solids rate.
- 05
Fine-gold scavenging
Re-treat the appropriate fine fraction when test work shows recoverable fine gold remains in the primary tailings.
Equipment roles, not a shopping list
Grizzly or feed hopper
Protects downstream equipment from uncontrolled boulders and regulates the feed rate.
Scrubber or trommel
Provides washing, attrition and initial sizing; selection depends on clay behavior rather than plant appearance.
Jig or sluice
Treats suitable coarse and medium fractions where particle size and density contrast support efficient recovery.
Centrifugal concentrator
Targets fine liberated gold in a controlled size fraction and should not be used as a substitute for proper classification.
Frequently asked questions
Can one standard wash plant treat every alluvial deposit?
No. Clay, boulder content, gold size distribution, water and feed variability determine the washing duty, classification sizes and recovery stages.
Do I need a centrifugal concentrator?
Only when representative testing shows recoverable fine liberated gold in a suitable size range and the feed can be classified and controlled.
What information is needed for an initial review?
Target capacity, feed size, clay behavior, known gold size or test results, water conditions, project country and photos or videos of representative material.