joubjonn
Well-known member
Some miller table tips, links to buy a nice one for $125 and a link to build your own. thinking of building one if i ever get a big supply of IC's (right now i only have a couple pounds). panning is a pain without a river of water, and just a pain all around for IC concentrate. the tips below are for gold mining concentrates and not exactly eScrap but i think the principles are about the same. i really don't believe that we have a perfect way to capture that IC gold that just doesn't sink and at the same time get rid of the ash for that first nitric wash, this method is probably the best in my opinion.
Build your own: http://www.scribd.com/doc/28318404/How-to-Build-and-Operate-a-Miller-Table
Buy one for $125: http://store.myprogold.com/index.php/equipment/clean-up-equipment/black-magic-fine-gold-recovery.html
Tips see below, REF: http://www.goldhog.com/gold_prospecting_forum/viewtopic.php?f=6&t=36
Tips for a Miller table... (NOTE: I am not an expert, so these tips are worth what you paid for them... not much)
The principle of operation.. In a sluice box, gravity is the primary force that separates the gold from the other materials... On a Miller table, Friction is the primary force at work... (Gravity plays a part, but friction is force to be managed)
1) Gold will not absorb water, so water will not "stick" to its surface like it does on almost everything else in your concentrates (like beads of water on a freshly waxed car). So, in the water flow, the surface of the particles of gold will have a lower drag coefficient (friction) than anything else in your concentrates.
(The shape of the gold particles does come into play on this, but dealing with that is balancing diminishing returns.)
2) The "trick" is to balance the friction forces (find the sweet spot) so there is enough friction to move everything but the gold...
Water flow... When Miller tables are discussed in these fourms, most of the conversation is about table surface... (just as I started this topic). However, it is my opinion that a "properly controlled" water "flow" will determine how well the table works. By water "flow", I mean all aspects of its flow, not just the volume of flow.)
As the water flow is what creates the friction, you must be able to control the flow precisely... The water flow should be uniform across the surface of the table, even, smooth, and non-turbulent, think of this as a "single" sheet of water "sliding" down the surface of the miller table... it should look as smooth as glass on its top surface... (it will get a little "rippely" as the water accelerates down the slope, but that’s ok... if it is running right, most of the "capture" action will occur within 6 inches of the infeed point...
I recomend using a gate valve rather than a butterfly valve to control the volume of water. I control the rest of the flow starting with feeding the water into a small "header tank" to stabilize the head pressure across the width of the table. The header tank discharges on to the Miller table through a full width x 2-inch long x 1/4 in thick section of corrugated plastic sign board. The small square channels create an even and non-turbulent flow.
Length of table... In my opinion, most Miller tables are much longer than they need to be (even my own). Mine is 1 foot wide, and 3 feet long... I wish it was 3 feet wide and 1 foot long ! The miller table "action process" has only one speed SLOW, it cannot be speed up or slowed down... (You can only do more of it, i.e. … a wider table)
3) In feed of concentrates... I often see Miller tables feed with a spoon... well.. that works... but it is not very efficient. This approach reduces the effective working area of the table, and it creates micro-turbulence... Slowly sprinkling a thin layer of (pre-wetted) concentrates into the flow works better for me.. (I use a pulsed vibratory full width feeder, because I am lazy)
4) a fine bristled 1-inch paint brush works great to manually move material around on the table surface while it is running, but when you get is set up perfectly, you should just let it run..
All of these things are just for your consideration.. a super-simple, not-complicated miller table will work... a more sophisticated miller table will work better, but is not absolutely necessary.. (I got by for years with a super-simple, spoon feed set up... but as the volume of my concentrates grew.. I needed a better more efficient solution.
I tried a lot of other things.. and then came back to the miller table… they are not fast.. they are not sexy… but , in my opinion, it’s hard to beat a properly operating miller table for separating micro-gold from concentrates…
Build your own: http://www.scribd.com/doc/28318404/How-to-Build-and-Operate-a-Miller-Table
Buy one for $125: http://store.myprogold.com/index.php/equipment/clean-up-equipment/black-magic-fine-gold-recovery.html
Tips see below, REF: http://www.goldhog.com/gold_prospecting_forum/viewtopic.php?f=6&t=36
Tips for a Miller table... (NOTE: I am not an expert, so these tips are worth what you paid for them... not much)
The principle of operation.. In a sluice box, gravity is the primary force that separates the gold from the other materials... On a Miller table, Friction is the primary force at work... (Gravity plays a part, but friction is force to be managed)
1) Gold will not absorb water, so water will not "stick" to its surface like it does on almost everything else in your concentrates (like beads of water on a freshly waxed car). So, in the water flow, the surface of the particles of gold will have a lower drag coefficient (friction) than anything else in your concentrates.
(The shape of the gold particles does come into play on this, but dealing with that is balancing diminishing returns.)
2) The "trick" is to balance the friction forces (find the sweet spot) so there is enough friction to move everything but the gold...
Water flow... When Miller tables are discussed in these fourms, most of the conversation is about table surface... (just as I started this topic). However, it is my opinion that a "properly controlled" water "flow" will determine how well the table works. By water "flow", I mean all aspects of its flow, not just the volume of flow.)
As the water flow is what creates the friction, you must be able to control the flow precisely... The water flow should be uniform across the surface of the table, even, smooth, and non-turbulent, think of this as a "single" sheet of water "sliding" down the surface of the miller table... it should look as smooth as glass on its top surface... (it will get a little "rippely" as the water accelerates down the slope, but that’s ok... if it is running right, most of the "capture" action will occur within 6 inches of the infeed point...
I recomend using a gate valve rather than a butterfly valve to control the volume of water. I control the rest of the flow starting with feeding the water into a small "header tank" to stabilize the head pressure across the width of the table. The header tank discharges on to the Miller table through a full width x 2-inch long x 1/4 in thick section of corrugated plastic sign board. The small square channels create an even and non-turbulent flow.
Length of table... In my opinion, most Miller tables are much longer than they need to be (even my own). Mine is 1 foot wide, and 3 feet long... I wish it was 3 feet wide and 1 foot long ! The miller table "action process" has only one speed SLOW, it cannot be speed up or slowed down... (You can only do more of it, i.e. … a wider table)
3) In feed of concentrates... I often see Miller tables feed with a spoon... well.. that works... but it is not very efficient. This approach reduces the effective working area of the table, and it creates micro-turbulence... Slowly sprinkling a thin layer of (pre-wetted) concentrates into the flow works better for me.. (I use a pulsed vibratory full width feeder, because I am lazy)
4) a fine bristled 1-inch paint brush works great to manually move material around on the table surface while it is running, but when you get is set up perfectly, you should just let it run..
All of these things are just for your consideration.. a super-simple, not-complicated miller table will work... a more sophisticated miller table will work better, but is not absolutely necessary.. (I got by for years with a super-simple, spoon feed set up... but as the volume of my concentrates grew.. I needed a better more efficient solution.
I tried a lot of other things.. and then came back to the miller table… they are not fast.. they are not sexy… but , in my opinion, it’s hard to beat a properly operating miller table for separating micro-gold from concentrates…
