Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

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Raising the heat. (3 replies and 1 comment)

K
ToddLaw
6 years ago
ToddLaw 6 years ago

I've got a mine with sulfides in my ore. For reasons unrelated I haven't been running my ore for 22 years. I used to burn my ore with a Beckett oil burner in a contained environment and extract the output with water. The sulfides would ignite in the environment and turn my pipes white hot. Due to my ore sitting around for nearly 22 years, my sulfides have lost their touch and I can't get them to burn. I've been working with a couple associates because I'm getting old and just can't do everything by myself anymore. The problem is, I've been at this for nearly two years now because we have to try everyone else's idea first. I've tried using magnesium oxide and iron oxide to make thermite, along with iron oxide and aluminum powder. But the problem is I can't get it hot enough to ignite. My burner takes me to about 1300° F and I need a way to get past that to get my ore going. I have another ore with coal, and if I could get the coal hot enough, I know I can get my sulfides to burn, but I can't seem to get hot enough. Most thermite ignites around 3000° F and I just can't get there. Does anyone have any ideas on how to raise the heat to get to where I need to be? I've tried amonium nitrate and nitric oxide. Just doesn't get hot enough. I'm open to any suggestions or ideas. Please help.

j
Jeremy tape
6 years ago
Jeremy tape 6 years ago

Have you tried to enrich your air, with O2?  N2 is just alone for the ride, but you lose heat due to heating up the N2.  A PSA plant is also very cheap or you can used bottled O2, but costs.    

K
ToddLaw
6 years ago

I have not tried using O2, however I have done this before, without using O2. The problem is my Sulphide Ore used to burn itself hot enough, that It would get white hot and I had no problems. Now, my Sulphide Ore is just too old and it's lost it's kick. The oil burner I'm using doesn't get hot enough to light any kind of thermite I throw into it. I'm thinking if I used coals, and got them burning hot it might add the heat I need to the mix. I have coal Ore as well and if I can get my coal Ore to burn, I might be able to mix it with my Sulphide Ore and get them both to burn together.

R
rushcard1
5 years ago
rushcard1 5 years ago
1 like by David

Not sure of the quantity of sulfides you are trying to burn, but an economical way for smaller amounts might be to use an old fashioned blacksmith forge.  The problem is that you will have no way other than visual to control your heat.  You can use a hand-held scanner to monitor this which are now available online or at some applicable stores.  Might have to try different types of coke.

Years ago when I first started experimenting around with melting larger quantities of ore than I chose to do in a muffle furnace, I located an old cast iron large combine piston which I thought would make an excellent crucible for melting some gold ore.  I did not have a hand-held scanner but thought it might work.  It actually melted the cast iron so then I had a container full of nice gold mixed cast iron by-products, along with some really cool home-made small obsidian pieces.  It did get hot enough to do this, which I estimate must have been between 4,000 and 5,000 degrees F.

Finding or acquiring a blacksmith forge is another story, though.  Maybe you can make one.  Seems when I was looking for one, the people who owned them quite often inherited them and knew nothing about using them, but felt they must be at least as valuable as museum pieces so they were not cheap to buy, but they will last forever if properly attended to. 

One guy locally where I bought mine was actually a professor at the SD School of Mines & Technology and taught a course in their operation there.  He had devised a quick and easy means to hook up the hand-blower to a small motor which frees up your hands to do other things while still monitoring the process.  His son still uses these to fabricate all kinds of wrought iron art which he sells nation-wide for decent money to a large following of folks to decorate their yards with etc.

Hope this is helpful to your endeavor -- good luck out there.      

F
Siddiquf
5 years ago
Siddiquf 5 years ago

ToddLaw, if your sulphide ore has been exposed to elements for 22 years, the sulphides may have been oxidized, at least on surface of each grain, and therefore may not be combustible any more irrespective of the initial ignition source you employ. Microscopic observation of a few polished sections can reveal the extent of the alteration. 

If surface alteration is indeed the case, your better bet would be to roast the ore, or rather a concentrate, in presence of excess air followed by leaching. A fluidized bed roaster is usually the best for this type of roasting. What is/are your value element/s?

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