Gold concentrators and gold recovery gold concentrators.

The “Martin” Multi-Helix

Spiral Gold Concentrators

OUR CLAIM: The Multi-Helix Spiral is “hands down” the most efficient gold concentrator available in the industry. It has a proven track record with a recovery rate of 99% of all free gold. It is a commercial duty, gravity concentrator for both alluvial and fine milled hard rock ores and has the highest concentration ratio AND highest recovery rate of any gravity concentrator on the market today.

The Multi-Helix Spiral allows for full adjustment to the ore-matrix or concentrate yielding a peak concentration ratio with virtually no loss of gold.

With the ability to adjust to any ore matrix, the spiral recovers all fine gold down to 100 mesh and less. So fine that it cannot be panned nor seen with the naked eye, only with a loop, resulting in a finish or smelting grade concentrate.

The Helix Spiral is more practical and more efficient than a concentrating table due to it’s simple operation, continuous feed and higher volume (4 times the volume of a 4’x8’ finish table). Send us your ore sample and we will show you what you are missing with your present concentrator!

Multi-Helix Gold Spiral




How it works: The actual "working surface" of the concentrator is made up of a series of leads (pronounced "leeds") running lengthwise “in reverse” in a critical tight spiral pattern along the inner barrel. The leads have a set angle on the uphill side and a counter angle on the downhill side, and are larger in height and width at the rear of the barrel than at the front. Exact angles and dimensions to create ultimate efficiency took hundreds of hours of trail and error testing. During operation, the decreasing height and width of the leads create the classifying effect as the ore passes through the barrel. As the ore is being classified, the gold and heavy concentrate settle into the bottom of the groves made by the leads and is conveyed upwards (in reverse). As the classified ore reaches the upper portion of the barrel, a set of angled spray heads continuously “wash back" the lighter gangue material while the gold and heavy concentrate continue moving forward, falling out of the groves and into the concentrate holding bin. This is a continuous process allowing the gold concentrate to be recovered in a hands off fashion while the waste is being discharged out of the rear of the Spiral. For larger volume processing, multiple Spirals can be installed in "series" with the ore being feed automatically from one Spiral to the next.

Versatility: For secondary and final processing of sluice concentrates, primary jig concentrates and centrifuge concentrates - fully adjustable allowing for "rough" and/or "tight" cuts, adjusts to a wide range of ores and concentrates to achieve a smelting grade product - also great for bulk sampling and testing head ores - continuous feed or batch feed - portability allows you to move around your site or work off site (indoors or outdoors) - classify any heavy metal or heavy mineral such as gold, silver, platinum, tantalum barite, scheelite, sulfides, tin, galena, lead shot and bullets etc. Great for recovery of mercury and tailings projects. All considered, the Helix Spiral is the most versatile and practical piece of mining equipment you will ever own!


The Helix Spiral is also excellent for bulk sampling. At this mine, they are testing head ores to assess the ore body and areas of the property with potential values for excavation. Exploration and ore body assessment is an important facet of alluvial mining.
Bulk sample showing good values of fine gold

portable gold helix spiral concentrator
In the field: The Spiral requires clean water with good pressure: 10-15 gpm at 30- 40 psi. Notice the attached 2" disc filter which is adequate for moderately dirty water and can be cleaned onsite.     Shown above with optional trailer - Cleaner model being used for sampling, proving out cocentration ratios and recoverable values at a sand and gravel operation in California.

Above: 25 ton/hour sliver galena processing plant that incorporates (four) 24" Helix-Spiral roughers and (four) 16" Helix-Spiral cleaners in conjunction with a single 20" Low-G Horizontal Centrifuge used as a scavenger. The plant uses a plate feed hopper that feeds the ore to a jaw crusher. The material is then conveyed to a three deck screen classifier - coarser material is re-crushed using two different roll crushers and then conveyed back to the screen deck - the finer material is conveyed to the Spiral roughers, then gravity fed to the Spiral cleaners. The tailings then fall off into the Centrifuge. The process takes 20 oz per ton sliver galena ore and concentrates it up to 1,800 oz. per ton. The entire plant was designed and built by Paul Clift and Tri-R Engineering.


Helix-Spiral Gold Concentrators in “Series”


Above: Scavenger Plant / Black Sand Tailings Recovery:

The recovery plant is a bank of 16" Reverse Helix Spirals, 5 “Cleaner models” and 1 "Finisher", all 6 running continuously in series. The plant processes 25-30 tons daily of pure black sand (tailings) from a larger alluvial mining operation in northern California (previously, the tailings were discarded or sold as a by product). The concentration ability of the Reverse Helix Spiral even in this extremely dense application reduces the 25-30 ton daily volume down to only 5 gallons (100 lbs), a concentration ratio of approximately 500:1. At the end each shift, the 5 gallons of primary concentrate is processed using only the "Finisher Spiral" (takes about 20 minutes) reducing the 5 gallons down to approximately 1 quart of a highly enriched concentrate. After several quarts are collected, they are combined and concentrated one last time with the Helix Finisher producing a "super con", a smelt-able grade, 98% gold product. No chemicals are used for the entire process.

Photos Below LEFT: 15.6 oz of fine gold recovered from black sand tailings. RIGHT: 80 oz. gold bar in each hand


Spiral Models and Applications

16” Reverse Multi-Helix Spiral - Cleaner - A continuous or batch feed secondary concentrator with a production rate of 1-2 tons per hour. An exceptionally versatile concentrator for processing primary sluice concentrate, primary jig concentrate, centrifuge concentrate, and milled hard-rock ores. Excellent application for mercury recovery and tailings projects.

16" Reverse Multi-Helix Spiral - Finisher - The Finisher model can be used in conjunction with our standard Cleaner to shorten cleanup time when concentrating large volumes, or in certain custom applications. Highest production performance is with fine concentrates of material less than 1/8”. Ask us for advice about your application. In 90% of cases, all your concentration and clean up needs are achieved with the standard 16” Cleaner.

Stand alone unit comes mounted on self supporting frame
1/2 hp electric motor / Weight - 675 lbs

Contact us for more info, specs and pricing

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Oro Industries

Lincoln, CA.

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