Watch these videos of the Vortex Drop Riffle Sluice Box in action!

The 6” Vortex Drop Riffle Sluices are made of 6061-T6 aluminum which is very durable. 12” Vortex Drop Riffle sluices are considered production or commercial sluices and are manufactured with 7075-T6 aluminum, one of the toughest alloys of aluminum available. The Goldwell sluice is the familiar gravity sluice type operation with some subtle and important differences.  Most notable is that the sluice does not generally require as much water flow as other typical sluices, and that the angle of operation for successful capture of gold is extremely forgiving, making it easy even for novices to set up and operate effectively

There are four basic adjustments to consider when using any sluice, including the Vortex Drop Riffle sluice. They are LEVEL, ANGLE, WATER FLOW and MATERIAL FEED RATE. Your sluice should be level, set at an appropriate angle for the water volume/flow rate and material feed rate desired. Much of this information is also included in the Owners Manual that is provided by the manufacturer with each sluice.

LEVEL: Every foot along the sluice, at the junction between two collection bed plates (the plates with the spirals in them) is a small V-shaped groove between two rows of spirals closer together than the rest. When processing material, you should see a small amount of black sands accumulate there. This is an indication groove. When set up properly, the black sands from one side to the other of the sluice should appear fairly even in this groove, appearing like a dotted line. If it is more pronounced on one side than the other, the sluice is not level. It might also be caused by a difference in the water flow from one side to the other of the sluice.

ANGLE: The sluice has been tested from 2 degrees through 25 degrees, and performs admirably throughout that range. This sluice has even been operated at a 45 degree angle and still captured gold, including fine gold. But for most purposes the angle of use should probably fall in the range of 5 to 15 degrees, depending on needs. (For reference, 1.5 inch per foot of length equals 5 degrees. 3.5 inches per foot of length equals 15 degrees) Steeper angles produce a higher water velocity and a lower quantity of material at cleanout. Shallower angles will result in a lower velocity, forcing a lower feed rate of material but may be optimal for extremely fine gold such as recovery from tailing piles. There is no absolute rule of thumb here. Simply, the sluice placed at any angle between 5 and 20 degrees will perform admirably and recover gold of all practical sizes extremely well. 10 to 15 degrees will give a good feed rate and water velocity combination that will fit most needs.  5 degrees will serve well for processing materials such as crushed rock or tailings which contain a lot of ultra-fine gold. The relationship between angle and flow rate of the water will ultimately determine the proper feed rate at that combination of  conditions. Spend some time testing your new sluice at different angles and feed rates to become familiar with how it works and what works best for you. Do not operate a Goldwell sluice to the specs of other types of sluices as it may not perform as well as it could. Most sluices are operated at 1 inch of drop per foot of length. The Gold Well sluice can operate at angles less than and far greater than this!

WATER FLOW: Once the desired angle and level are established for the sluice, you will want to adjust your water flow. The flow is in the proper range when particles in the vortex pockets show circular motion. To do this you should set the water flow rate low, add a few scoops of dirt, then while watching the sluice pockets, slowly increase the flow rate UNTIL you see the material in the gold wells begin to rotate. This then will be the minimum water flow that you want to maintain in your sluice for proper operation. The water flow volume will be different for different materials. If the bulk of the material you are processing is light, you may want to run enough through the sluice first to get some heavy black sands built up, then adjust your water flow for the black sands, not the lighter silicon dioxide sands (generally the light colored sands).

Water flow through the sluice should be between 2 and 8 gallons per minute per inch width of sluice. So a 6 inch sluice should have a water flow of 12 and 30 gallons per minute. The water flow should not go below this. A 12” sluice should have 24 to 96 gallons per minute supplied, but have been run as high as 150 GPM. Just because your valve or throttle or pump speed control may have a "wide open" position, keep in mind that does not automatically mean that wide open will be the best flow rate for the material your are processing.

The worst condition that you can have is scrubbing out the wells in the sluice! If the spiral wells are not keeping material in them (let the water run for a bit and see if the wells totally empty out), the sluice has either too much water velocity or too much angle or both. Scrubbing of the top row or two of spirals in normal. Only larger gold should be able to rest in these rows unless you are running at extremely low velocity and angle for super fine gold recovery.  TIP: Adding a small amount of dish soap or Jet Dry to the water to break surface tension may reduce losses of ultra-fine gold when processing crushed ore or using the sluice in areas that have a high concentration of ultra fine gold. Do not add so much that the water gets foamy.

PROCESSING MATERIAL: The maximum feed rate is determined primarily by the water flow rate and the angle of your Vortex Drop Riffle Sluice. Increasing angle or water volume will allow a greater volume of material to be processed per unit time. If you have a lot of extremely fine gold, like when you are processing tailings, you may want to reduce the angle and increase the flow rate to keep a reasonable feed rate. If you are used to a normal sluice, you will find that the Gold Well Vortex Drop Riffle can process more material faster than you are used to. IF material is building up and staying for a period of time on the flat areas of the sluice between the wells, you are feeding the sluice TOO fast.

The sluice is designed to process unclassified materials provided enough water depth is delivered to the sluice to move the large material through the sluice.  If sufficient water can not be delivered, either classify the materials to 3/8” or less and/or increase the sluice angle to help large material to move through the sluice.  Classified materials will have the highest recovery, however, that is not to say that unclassified material will have poor recovery.  To the contrary.  In all the tests done so far, even unclassified materials, the recovery rates are still in excess of 95% for most gold.  In some tests involving crushed ore from a vein, where the gold was 400 mesh and finer, the recovery was around 80% but that was due to the fact that gravity type systems do not typically do well in recovery of gold that is so small it is capable of staying in suspension in the water flow.

When working with materials that compact easily or are extremely sticky, such as material with a lot of clays in it or jagged crushed rock, check the Wells from time to time by taking a small probe and seeing if the material in the bottom of the Well moves around freely. If it does not move easily and is compacted, you may want to empty the sluice more often, or add some soap to the water to keep clay from re-adhering to itself in the sluice.

The sluice may be run at a wide range of attack angle. You should test the sluice at different angles to see what is best for the material that YOU are processing. Like any sluice, there will be an optimum water flow and angle for the material you are working with. One way to test this is to carefully pan out some samples of processed material (dirt that has already been put through the sluice) and look for fine gold there. Another way is to re-process the dirt and see if there is gold captured on the second pass.

CLEAN OUT: To empty the sluice, you should have a 5 gallon bucket or a small tub to stand it up in and flush it out into the bucket or tub. DO NOT spray it with an aggressive jet-like stream of water, as this may spray the water out and away from the sluice, as well as gold. Simply flood the pockets with adequate water, starting at the top and work to the bottom, then repeat until you are satisfied that all material in the sluice has been transferred to the bucket. From there you can then transfer it into a gold pan or some other final separation device. The quantity of material (black sands and unwanted silicate sands) will be about half of a cup. This greatly reduces the amount of material needing to be removed to get to your collected gold, and as a result, greatly reduces losses in the cleanup process.

CLEANING THE SLUICE: The sluice boxes are made from aluminum and stainless steel and will not corrode significantly in normal environments. Contrary to popular belief, salt water does NOT CORRODE ALUMINUM!  However, salt water DOES create galvanic corrosion between dissimilar metals, which DOES cause corrosion.)  After use, rinse the Goldwell sluice in clean water to remove black sands and other minerals that contain iron, lead, silver, etc., which will cause corrosion over time if wet and left in the sluice.  Do NOT use cleaners that contain ammonia or have a ph higher than 7 (alkaline). Use an acidic cleaner such as vinegar or vinegar and water to clean the sluice up if you want to clean it or an aluminum cleaner or polish.

Waterfall heads should be opened from time to time and cleaned of sediments in the bottom (flush out good with a water hose).  The sediments will not interfere with proper operation and will only deposit in the quiet areas in the waterfall head where water flow is not significant.

ATTACHING YOUR OWN PUMP & HOSES: If you want to use a pump and hoses you already have or want to purchase those parts locally, keep in mind that pumps should be bilge or trash type pumps, designed to pump water that may contain debris. Other types of water pumps may work but may deteriorate much faster from pumping dirty water that contains abrasive fine sediments and organic material that may be recirculated in a closed system.