Reclaiming lead

Imagine 22,000 lbs of ground-up tires with all the steel and other crap removed, ground to @ 1/8" pebbles. This is the material in the backstop of a shooting
range. There is a conservative estimate of 10,000 lbs of lead and copper to a much lesser degree in the rubber. This isn't the first clean-out/rebuild, the last one was five years ago. The idea is to remove all the material, separate it and reuse the rubber. One of the ideas we've had is to float the rubber in water and skim it off. But, 1/2 of a sample amount floats, 1/3 sinks and 1/6 stays suspended. In a 1/3 cup of the material, there was 64 grams of lead! I doubt that there is much lead in the material above the target line. The sample was taken at the very bottom, about 5' below the target line. They don't really want the range down for more than a week to do the clean-out and replace the front which is 4' wide x 3/4" thick conveyor belt lengths suspended from the ceiling and anchored to the floor and overlap by 8" and screwed together. The conveyor belting is bulging out close to a foot in the center of each of the ten lanes. It seems that this type of backstop is excellent for stopping bullets and keeping the dust to a minimum.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Get a air blower (like those used to dry carpets). Rig some kind of a conveyor thing to dump that stuff in front of the blower. The blower will blow the rubber away, but the lead will fall down.
i
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I would worry that a blower would blow all sorts of lead dust everywhere.
How about a something like a gold sluice box? There are a lot of designs on the web. You would probably want to re-circulate the water and then let it evaporate after you are done so you do not contaminate much else.
Or, if you stick with your original idea of dumping it in a water bath, I bet a little agitation would bring some of the sunk rubber pieces near the surface where you could scoop them out.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

WW:
Rotary sieve shakers that add an upward tapping motion in the process are used in various kinds of particulate separation. I offer no assurance this would work for you. Your hope would be that the heavier particles would work to the bottom and any light particles that might be trapped by adjacent weightier material would eventually find their way to the top as the initially heterogeneous bottom layer is periodically disturbed by the upward tap. After a period of the described action, a weighted separation of materials would be the goal.
I am quite familiar with smaller machines that do this but bigger things are available. Metals and rubber are a mix outside of my experience.
Sweco and Gilson are shaker manufacturers you may want to talk to, among others. As a broader industrial category, "material separation" might be a starting heading.
Regards,
Edward Hennessey
Regards,
Edward Hennessey
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Usually sand is used, this is the first I've heard of rubber being used except as whole tires. Sand can be sieved and returned for reuse easily.
Anything floating or suspended you may take as NOT being all lead, but may have some contamination, Shaker tables have been used for separating heavy from light materials, the problem is going be the dust. Done on an industrial scale, there'd be a cyclone separator and a bag house for filtering the air. So probably the dust needs to be removed first, then run floatation or a shaker table. You can see how a shaker table works in old books on placer gold mining. Fines are always a nasty refining problem, both for collection and rework. Right now, you've got 15-16 tons of toxic waste. Hope you've got bunny suits and respirators.
Stan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I would do the dump in water and separate out the half that floats. Then add new material to rebuild the backstop. Then in five years when you do this again, 3/4 of the material ought to float. If you keep reusing material that sinks, you will have just as much work every time you do this.
If possible I would sell the material that sinks and stays in suspension, to someone that is in the scrap business. Not really worthwhile to make a system you will only use every five years. If that is not feasible then build a relatively small sluice system and take your time reclaiming the lead. The range will be up and in use with the new material added to the material that floats.
Some of your members might even do the work of reclaiming the lead in return for lead to use in casting bullets.
Dan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Our club is also reclaiming our lead from the 50 year old backstop. In our case the backstop is just dirt, and plenty of clay as it turns out.
We dug up about 100 cubic yards of dirt and piled it in large windrows to dry out all summer, tented under tarps. I have put together a nice line of equipment to sort the bullets out.
We start by dumping the dirt into a Royer 120 dirt shredder which pulverizes the dirt and throws it onto a vibrating screen machine that I designed and built. The sifted dirt falls onto a 30' long grain elevator, which piles it back on the range. The concentrated lead/gravel/clay clumps roll off the sreeen onto a small wagon, which we haul into a pile.
So our concentrate is similar to what you start out with. We have one member who has a lot of gold mining equipment. We have done a test run using a gold sluice and it looks very promising. When the weather gets better we will use his larger sluice to trap the lead, leaving a pile of tailings to place back on the range.
The big problem we have is large clumps of clay which will not feed through the shredder. I just bought a old hammermill from a landscaping business. I am looking around for a suitable engine. A Yanmar 22 hp diesel just sold on eBay which would have been perfect, but it was 300 miles away. There is a huge equipment auction coming up in a few weeks that has dozens of engines, I'mm coming away with one of them!
I am building two smaller conveyors from parts I got at HGR to feed into the hammermill and connect the mill to the shredder.
You should keep in mind the environmental issues. The EPA does NOT regulate operating ranges, but they do regulate the ground and surface waters, so any wash water needs to go back into the backstop if it has lead in it.
The EPA does have a very practical manual titled, "Best Management Practices for Lead at Outdoor Shooting Ranges", which are recommended guidelines. If you don't have it, you can download it at:
http://www.epa.gov/region2/waste/leadshot/download.htm
As we process our dirt, I adjust the Ph with lime, and add phosphate to bind any lead that does get dissolved, as per the EPA manual. I add a measured amount of the chemicals to each load of dirt that goes in the shredder.
--
DT



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

DT:
You may want to look at solvents/detergents that might break down your clay. There was a proprietary formulation (Quaternary O?) that some folk had luck with. If you come up with something along that angle, it would be good to know.
Regards,
Edward Hennessey
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 10 Feb 2011 08:16:57 -0800, "Edward Hennessey"

Too late now, the material to use is gypsum. Must be incorporated and takes time.
Karl
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@yahoo.com says...

Interesting, I haven't heard of that. Hopefully our brute force method, flailing hammers at 20,000 ft/min, will do the trick. One of our members actually used to run this hammermill many years ago and spoke quite highly of it. We will most likely be running it at much slower tip speeds, since we just need to break up the clumps, we don't want to shred the bullets.
--
DT



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Salt the water. More than half will float.
A shot tower that dribbles bits from above, with a suitable crossventilation source, can separate the wheat from the chaff, too.
How do grain separators work? Can you rent a threshing/winnowing gizmo?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

way too light weight.
That gave me this thought, truck it to the gravel pit and run through the rock separator. the lead would come out the pea rock dump the rest would go on through. Then truck it back.
Karl
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I hate to be a stick in the mud here but if the State or Federal EPA gets wind of what you are planning to do all H&*@ will break out and you could see big fines and possible jail time.
Laws were just changed last year requiring full bunny suit and hazards waste disposal for the paint chips if the house has lead paint.. Get caught breaking the rules and the contractor/homeowner sees $33k/day in fines. You are talking about tons of lead and lead dust.
The company I work for used to have a shotgun range just outside the gate. Five years ago they decided to develop the land and ended up spending several million dollars cleaning up the lead. Needles to say we didn’t get a new shotgun range
I thnk the lead laws are stupid there are a lot worse hazards that are compleatly unregulated.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

EPA or OSHA rules. Our club has no paid members so we are exempt from OSHA. We had an encounter with a MiOSHA type that was checking up on high lead levels on a member that *thought* he was getting a lead blood screening to be safe under the doctor patient privilege. Not so. High levels are automatically reported to the State of Michigan.
This person is a hard core shooter, bullet caster, and has his own indoor range. Definitely in the 99.xxx% of shooters. Where his lead level came from is hard to tell.
We had a MiOSHA guy intent on throwing his weight around, eventually after some lawyer time, we sent him packing. So much for doctor patient confidentiality and that was pre Obama.
Wes -- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I wouldn't touch it with a ten foot pole.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Some of the vendors of this sort of range have auger systems to separate the lead. My club just installed a new backstop with the auger system included, but I haven't seen it, so I have no idea how it works. My understanding is that you can get the backstop without the auger, and then hire the backstop company to come & periodically clean the lead out. Another club in my area has a pulverized rubber backstop, and they have some means of cleaning it, but I don't think they have an auger system.
If you got the pulverized rubber from a commercial backstop vendor, I would hope they have a means of getting the lead out.
Doug White
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 2/10/2011 12:14 AM, Whole-Wit wrote:

If too much rubber is sinking, switch to salt water? The more concentrated, the more the rubber will float. After the piles are sorted, you could rinse the rubber and lead with fresh water if the salt bothers you. Since the rubber is ground fairly small, you could use a 1/4" or 3/8" mesh to get the .38 and bigger bullets out first. I assume the lead doesn't break up very much in your backstop, ours is a steel plate, much of our lead is in dime to quarter size discs.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I tried saturated salt water and it seemed to make no difference. The sampling shows the lead breaks up more than half the time and jacketed HP bullets fragment, there's about 25% of the lead that is 1/8" or smaller. It surprised me too! Whatever is done, the club has many public officials as members and the job will be done all above-boards with respect to all regulations and safety. We just want to do it as cheaply as possible and it would be nice to have a good, on going solution. I would like to get my hands on a few cubic feet of cheap lead.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

A few years ago (like 10) I went to a gun range, and they gave me a bucket of floor sweepings. It probably weighed 100 lbs. I remelted this stuff into ingots.
i
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.