Heap Leaching Simulation Column

Sampling valves, air diffusers and connection lines positioned at different levels of the heap leaching column

Upper solution distribution nozzle, sampling valves and air connections of the heap leaching simulation column

Bottom solution outlet valve and removable collection tank of the heap leaching simulation column

DESCRIPTION

The ÜNAL Heap Leaching Simulation Column is designed for laboratory- and pilot-scale heap leaching studies in which solution flow, metal dissolution, aeration and process parameters need to be investigated under controlled conditions.

Its transparent PMMA body enables continuous visual observation of the ore bed, solution distribution, liquid level and overall process behaviour. The system is equipped with an adjustable industrial peristaltic pump, a stainless-steel solution distribution nozzle, multi-level sampling ports, independently controlled aeration points and a removable solution collection tank.

The divided collection tank allows the leach solution to be recirculated while helping to reduce the transfer of sediment and solid particles into the pump suction line.

Brand: ÜNAL
Country of Origin: Türkiye

Main Column Body

Transparent PMMA column body
Continuous visual monitoring of the process
PVC or AISI 304/316 stainless-steel fittings and sealing components
Internal diameter: 200 mm
Total column height: 1000 mm
Corrosion-resistant and easy-to-clean construction

Solution Distribution System

A stainless-steel nozzle located at the top of the column provides controlled distribution of the leach solution over the ore bed.

Nozzle material: 303 stainless steel
Orifice diameter: 0.38 mm
Approximate flow rate:
- 27 ml/min at 1 bar
- 33 ml/min at 1.5 bar
Bottom filter opening: 250 microns
Filter size selected for compatibility with the nozzle system
Controlled solution feeding and distribution

Sampling Ports

Sampling ports are positioned at 200 mm intervals along the height of the column.

These ports allow periodic samples to be collected from different column levels during the test. This makes it possible to monitor changes in metal dissolution, pH, reagent concentration and other process parameters throughout the ore bed.

Aeration System

Air diffusers are positioned at 200 mm intervals along the column height. The system allows controlled aeration to be applied at different levels of the ore bed.

Four individual airflow control valves
Independent airflow adjustment
Corrosion-resistant air hoses
Non-return valves to prevent reverse flow
Controlled air distribution throughout the column
Suitable for aerated leaching and oxidation studies

Pumping and Recirculation System

An industrial peristaltic pump is used to feed and recirculate the leach solution at a controlled flow rate.

Pump type: Industrial peristaltic pump
Adjustable flow range: 1–1140 ml/min
Operating pressure: 1–1.5 bar
Operation: Suitable for continuous 24/7 operation
Internal calibration
Flow accuracy: ±0.5%
Easy adjustment and control of the solution flow rate
Pump mechanism does not come into direct contact with the process solution

Solution Collection and Solid Separation Tank

A 5-litre collection tank is provided for each column.

The tank is vertically divided into two compartments. An approximately 20 mm gap beneath the central partition allows solution transfer between the compartments while helping to restrict the movement of larger solid particles towards the pump suction section.

Tank capacity: 5 litres
Two-compartment internal design
Approximately 20 mm bottom clearance beneath the partition
Pump suction line positioned approximately 30 mm above the tank bottom
Designed to reduce sediment intake
Helps minimise the risk of pump-line blockage
Facilitates solid recovery and frequent cleaning
Removable clip-on or sliding tank design

Pump Tubing

Approximately 0.33 m of high-durability polypropylene-based tubing inside the pump head
Approximate continuous operating life: 15–20 days
Approximately 2–2.5 m of economical silicone tubing for external connections
Recommended pump-head tubing replacement interval: 2–3 weeks
Quick and straightforward tubing replacement

Tubing service life may vary depending on the chemical composition and temperature of the solution, pump speed and operating duration.

TECHNICAL DATA

Equipment & Accessories

The Heap Leaching Simulation Column is supplied as a complete system with the auxiliary equipment required for controlled and continuous testing.

The system includes:

Industrial peristaltic pump with an adjustable flow range of 1–1140 ml/min
303 stainless-steel solution distribution nozzle with a 0.38 mm orifice
250-micron filter at the bottom of the column
Sampling connections positioned at 200 mm intervals
Air diffusers positioned at 200 mm intervals
Four independent airflow control valves
Non-return valves
Corrosion-resistant air hoses
High-durability process tubing for the pump head
Silicone tubing for external connections
A 5-litre, two-compartment solution collection and solid separation tank
PVC or AISI 304/316 stainless-steel fittings and sealing elements
Mobile supporting frame with castor wheels

The collection tank can be removed easily for cleaning and solid recovery. Its pump suction line is positioned approximately 30 mm above the bottom to reduce sediment intake and minimise the risk of blockage.

Applications

Laboratory-scale simulation of heap leaching processes
Column leaching tests
Hydrometallurgical testing of gold, copper and other metallic ores
Investigation of solution flow and distribution through an ore bed
Controlled aerated leaching tests
Reagent consumption and metal recovery studies
Periodic sampling from different levels of the column
Continuous solution feeding and recirculation tests

Operating Principle

The prepared ore sample is loaded into the transparent column according to the required particle size distribution and bed height.

The leach solution is drawn from the collection tank by the peristaltic pump and delivered to the stainless-steel nozzle located at the top of the column. The solution is distributed over the ore bed at a controlled flow rate and percolates downward through the material under gravity.

As the solution passes through the ore bed, it comes into contact with the mineral particles and dissolves the targeted metal components.

Sampling ports positioned at 200 mm intervals allow periodic samples to be collected from different levels of the column. This enables the progression of the leaching process and changes in relevant process parameters to be monitored along the column height.

When required, controlled aeration can be introduced through the air diffusers located at different column levels. Four independent control valves allow the airflow to each aeration line to be adjusted separately.

After passing through the ore bed, the solution flows through the 250-micron bottom filter and enters the divided collection tank. The tank design assists sediment settling and helps prevent solid particles from entering the pump suction line.

The collected solution can then be pumped back to the top of the column for closed-circuit recirculation. Depending on the test requirements, the system may be operated either in continuous recirculation mode or as a single-pass process.

The transparent column body allows the operator to observe solution distribution, ore-bed behaviour, liquid level and possible channel formation throughout the test.

ÜNAL Leaching Columns

ÜNAL Engineering has been designing and manufacturing laboratory- and pilot-scale mineral processing and hydrometallurgical equipment since 1987.

Drawing on our long-standing engineering and manufacturing experience, we produce leaching columns and heap leaching simulation systems for the investigation of different ores and process conditions.

Our leaching columns are not limited to standard dimensions. Column diameter, height, number of columns, solution feeding arrangement, pump capacity, sampling locations, aeration configuration and collection tanks can be customised according to the customer’s test programme and process requirements.

Depending on the process conditions, different construction materials, fittings and sealing elements can be evaluated. PVC, AISI 304 or AISI 316 stainless-steel components can be selected according to the chemical solution, operating temperature and corrosion-resistance requirements.

ÜNAL leaching systems can be customised with:

Different column diameters and heights
Single- or multiple-column configurations
Adjustable peristaltic pumping and recirculation systems
Alternative solution distribution and nozzle arrangements
Sampling ports at customer-defined levels
Controlled aeration and air diffuser systems
Special collection tanks designed to assist solid-liquid separation
Mobile, stationary or modular supporting frames
Manual or automation-ready process control arrangements

Our designs prioritise easy process observation, convenient sampling, controlled solution flow, straightforward cleaning and rapid replacement of consumable components.

Since every ore has different mineralogical characteristics, particle-size requirements, bed heights, flow rates and chemical conditions, ÜNAL offers flexible and project-specific laboratory- and pilot-scale leaching systems rather than limiting customers to a single standard configuration.

With engineering and manufacturing experience dating back to 1987, we provide reliable and customised leaching columns for universities, research laboratories, mining operations and process development centres.