Centrifuge
Low-G Horizontal Centrifuge Primary Concentrator
If you can't see it with the naked eye, the Low-G Centrifuge will recover it. A skilled panner can recover free gold down to 100 mesh, and our Low-G Centrifuge has equal ability for free gold recovery. However, in a production environment, recovery rates using gravity separation methods for gold particles down to 200–300 mesh begin to...
If you can't see it with the naked eye, the Low-G Centrifuge will recover it. A skilled panner can recover free gold down to 100 mesh, and our Low-G Centrifuge has equal ability for free gold recovery. However, in a production environment, recovery rates using gravity separation methods for gold particles down to 200–300 mesh begin to decline with any gravity separation method. We claim 99% recovery of free gold down to 100 mesh and 80% to 90% recovery down to 200 mesh.
Recovery rates of free gold particles at less than 300 mesh start getting out of reach of physical concentration means and require chemical separation methods. Gold measuring in the 300-mesh range is almost colloidal and tends to stay in suspension in the turbid water. Even in clear water, this ultra-fine gold stays in suspension almost indefinitely in a production environment. Claims of high recovery rates of 300 mesh gold in a production environment using physical (gravity) means are simply not true.
Oro Industries's Low-G Centrifuges are available in three sizes: the 16", the 24", and the 30". All Low-G Centrifuges are primary batch-type concentrators for both alluvial and milled hard rock ores. They are designed and engineered for continuous commercial-duty use and are bulletproof.
The Low-G has the ability to recover finer gold at a higher recovery rate than any other concentrator on the market today. The reason for this is that the Low-G is a centrifugal concentrator, not a gravity concentrator. That means it's not reliant on gravity settlement; the values are forced into the concentrate chambers by centrifugal force. This yields a greater recovery of fine gold.
Since the Low-G is a batch-type concentrator, you can achieve very high concentration ratios with most types of alluvial and hard rock ores. In fact, you achieve a much greater ratio than any gravity concentrator is capable of producing. In most cases, you can run it all day before you retrieve the concentrate from the centrifuge. To retrieve the concentrate, simply slow down the centrifuge, and all of the concentrate will come out within 30 minutes.
After a whole day of production, this concentrate is rich, so be careful how you handle it. The best way is to process it with Oro Industries's Multi-Helix Spiral Cleaner and Finisher. These Spirals are designed to take the centrifuge concentrate and give you fine, clean, and free gold at the highest recovery rate possible.
The setup and operation of the Low-G centrifuge are easy. It needs to be on a level surface of wood, steel, or cement. Each centrifuge has a standard pipe flange feed connection and comes with a swing discharge trough. The trough is down when running production, and you swing it up to retrieve the concentrate into a receiving bin. To operate the centrifuge, set the running speed to its indicated running RPM value located above the tachometer by turning the speed control knob.
Start the water flow and begin feeding the ore. When you are ready to retrieve the concentrate, place a receiving bin under the discharge trough. Stop ore feeding, slow down the water to around 25 GPM, and let it run at full RPM for 10 minutes. This will clean out excess material away from the concentrate. Swing up the discharge trough and start slowing down the centrifuge by turning the speed control knob. Lower the RPMs in increments of 100 every 5 minutes.
At half the running speed, you'll start to see the heaver concentrate and gold beginning to discharge. Keep slowing down the centrifuge by increments of 50 RPMs every few minutes until you reach 200 RPM. At that speed, all the concentrate will come out in 10 to 15 minutes.
Theory of Operation
The Centrifuge is a low G-Force batch-type concentrator designed to operate with clean or turbid water, which makes it ideal for recycle and recirculation applications. It is a continuous feed (water and ore) concentrator and "batches" the concentrate during the run process. In operation at a specific G-Force, the internal chambers fill with lighter material, which will form soft fluidized "beds." Gold and heavy minerals...
The Centrifuge is a low G-Force batch-type concentrator designed to operate with clean or turbid water, which makes it ideal for recycle and recirculation applications. It is a continuous feed (water and ore) concentrator and "batches" the concentrate during the run process. In operation at a specific G-Force, the internal chambers fill with lighter material, which will form soft fluidized "beds." Gold and heavy minerals and metals are forced to the walls of the chambers where they are trapped.
As the slurry continuously enters the Centrifuge, the heavier particles displace the lighter particles. At startup, the material starts collecting in the first set of chambers. When the first chambers are full, the material passes to the second chamber and so on until the Centrifuge is full. Under continuous run throughout the day, the heavy particles are displacing the lighter particles.
At the end of the process day, the heavy concentrate is cleaned out by simply decreasing the speed and flushing the concentrate into a receiver. In most cases with typical alluvial and hard rock ores, a properly sized Centrifuge will give you a full day's production before it.
Specifications
16" Horizontal Centrifuge
• Classified material feed: 1/4" or 3/8"
• Production capacity: 15 tons/hour – 10 cubic yards or 8 cubic meters
• Water consumption: 100–150 GPM/378–570 liters per hour
• Concentrate capacity: 25 gallons/440 lbs/95 liters/200 kg
• Power: 7.5 hp/3-phase – 60 Hz electric motor/variable speed hydraulic drive
• Dimensions: 115" x 30" x 38" (L x W x H)
• Shipping weight: 1500 lbs.
• Requires 6–8 weeks for delivery from time of order
• Capacity ratings are dry weights and volumes of ore classified to 1/4" minus.
• Actual water consumption depends on clay content and the required washing of ore.
• We stock all centrifuges and can ship on the same day as order confirmation!
24" Horizontal Centrifuge (Not Sold as Stand-Alone Unit)
• Classified material feed: 1/4" or 3/8"
• Production capacity: 25 tons/hour – 18 cubic yards or 15 cubic meters
• Water consumption: 150–250 GPM/570–945 liters per hour
• Concentrate capacity: 35 gallons/600 lbs/130 liters/300 kg
• Power: 10 hp/3-phase – 60 Hz electric motor/variable speed hydraulic drive
• The 24" Centrifuge is only manufactured for the MPP25 and MSTP25 and is not sold as a stand-alone unit.
30" Horizontal Centrifuge
• Classified material feed: 1/4" or 3/8"
• Production capacity: 40 tons/hour – 25 cubic yards or 20 cubic meters
• Water consumption: 200–400 GPM/755–1500 liters per hour
• Concentrate capacity: 50 gallons/880 lbs/200 liters/400 kg
• Power: 10 hp/3-phase – 60 Hz electric motor/variable speed hydraulic drive
• Dimensions: 145" x 40" x 64" (L x W x H)
• Shipping weight: 4200 lbs.
• Requires 6-8 weeks for delivery from time of order
• Capacity ratings are dry weights and volumes of ore classified to 1/4" minus.
• Actual water consumption depends on clay content and the required washing of ore requires flushing.


Versatility
The Low-G Horizontal Centrifuge is an excellent batch concentrator for primary recovery at volumes of 15-40 tons/hour. It is very economical for high volumes of typical alluvial or milled hard-rock ores and is adaptable to any existing classifying circuit. Multiple units can be connected in simultaneous feed for higher volume throughput.
These concentrators perform well with turbid water, which makes them great for recycle loop applications (ponds). For peak production capacity, we recommend classifying the head ore to ¼" minus.