How to distinguish briquette and lump charcoal dusts?

I have found a great resource for biochar. The "resource" produces oak- char and then sells it to a middle guy in Istanbul. The middle guy sells bigger pieces and dust (what they call it, actually those less than 1/4 of an inch) are dumped into a storage area. He wants that place to be cleaned out (more than 100 cubic meters of material I think). Unit cost of bringing it in will be roughly 0.2 dollars per kilo or or 9 cents per pound. I am planning to make a significant purchase (for my scale), mix it with manure and eventually use it.
My question is;
Since the middle guy sells other types of char also (even though he claims those are always in bags and not dumped), I want to be absolutely sure what I am bringing in is not petroleum sprayed stuff or such that will harm my garden. How can I test whether the "dust" is what I am looking for? How can I understand whether it is contaminated with other types of char? I need a practical way to test it on site. Something like a simple flame test, just making up now: "if the flame is lilac than it has potassium inside and they add potassium-something to enhance blabla so it is no good". Or a float test or "pour it on the water if there is oil on the surface no good" or density test? Just thinking out loud. Since it is mostly dust, I can't check clicking sound or color or brightness or such.
Another question, would you advise me to make such a purchase? Any reasons not to go forward?
Any ideas? Thanks :)

The only way I can think of it possibly being contaminated is if the wood, before it was turned into char, was contaminated and then only if if had an insufficient burn to convert it to char. From what I understand, any petroleum based anything will be burned off during the char making process. And I can’t imagine why anyone would want to add chemicals to a char after it’s produced, that makes no sense to me, so I think it’s going to be safe. As far as “other types” of char, when wood is turned into char, it essentially becomes pure carbon, and it’s my understanding that there really is no difference if it was once oak or hickory or any other type of wood beforehand.

It sounds like a good source of char to me, and I’d buy it.

James,
Thanks for a quick reply. I couldn't express myself. My biggest concern is commercially produced, chemical added and compressed chars (added a picture). Or are they called pricketes? By other kinds of coal I mean mined, imported or manufactured; and those are being sold at the same place. They do have nasty chemicals inside I suppose. As you said, not many chemicals can survive those temperatures. But I don't want to dust of the coal of which's picture I added.
Thanks again.
Edited to add: Is there a easy/possible way to distinguish dust of "manufactured coal" (picture added) and char (we produce) for biochar?

Lump (natural) charcoal would not have any contaminates since they would be incinerated in the process of making the charcoal.

Processed charcoal briquettes are a totally different story, there are binders (glues) and waxes along with petro products (those self lighting and or quick lighting briquettes).

As long as you avoid all "man made" briquettes and pieces of briquettes you should be fine, and what a resource you have found.

Redhawk

So I suppose what you will be looking for is fragments of those formed briquettes that contain petroleum binders and waxes. If the "dust" is free of obvious pieces of briquette, you're probably in the clear.

I think it important to keep in mind that there can be something of a draw-down of soil activity as the charcoal is colonised, so inoculating it is crucial. After it is inoculated, I think tests can be performed in pots with a potting mixture in appropriate ratios, perhaps a little heavy on your new biochar using any variety of quick-germinating seed, but preferably more than a single test species.

I wonder, kola Redhawk, if you could detect a difference in the quality of soil life through the microscope, comparing weathered fragments of briquette and charcoal both. Would anything colonise the briquette bits? Would there be the same soil life, just fewer and sicklier, or would the presence of the petroleum contaminants draw or nurture different soil life that we may not want there?

Or would briquette fragments appear physically different from natural charcoal, the binders and waxes filling in the spaces microbiota make homes in?

-CK

hau Chris, (I went back to my note books to find this graduate study two of my fellow students and I performed for our masters in biology, I have condensed parts of the paper)

We did that study of lump charcoal vrs. briquette back in 1984, just after the "match lite" briquettes came on the market.
Our method was to take three sets of samples of each, lump charcoal, "Kingsford "regular" and Kingsford Match lite" for the study.

set one was set out in open air, exposed to all the elements 24 hours a day for 90 days.
set two was set out in open top containers (with drain holes open) with freshly dug garden soil sprinkled over the samples of the set until they were fully covered..
set three was set out in open top containers (with drain holes open) and sprayed with a compost tea and a mushroom slurry.
The tea was sprayed on at the onset of the time period of 90 days and again every thirty days.
The mushroom slurry was applied 3 days after each of the tea treatments. This meant that neither was sprayed at day 90, that was when the sets were to be examined for microbe counts within a square cm. grid plate

At the end of the 90 days samples were examined under the microscope at 2500x with standard polarized illumination using a polarizing filter and a high intensity bulb, the diaphragm was set at 50%.

set one showed no microbial organisms living in either of the briquette samples, the lump samples showed 100 bacteria per cm. and 18 fungal strands per cm.
The conclusion was these organisms had settled from the air to populate the sample.

set two showed microbial organisms living in the "regular" briquettes, counts were 58 bacteria per cm. and 2 fungal strands per cm., but no living organisms in the "match lite" sample, the Lump charcoal sample had 1500 bacteria per cm. and 59 fungal strands per cm.
The conclusion was that organisms from the soil readily inhabited the regular briquettes but were prevented from fully colonizing because of the binders used in manufacturing process. The "contaminates" of the match lite sample were determined to be the cause of no inhabitation by microbes.
The lump charcoal, with the high for this sample set inhabitation showed that it was the most suitable for sustaining microbe life and colonization.

set three showed the regular briquettes with 500 bacteria per cm. and 28 fungal strands per cm., the "match lite" samples contained 16 bacteria per cm. and 2 fungal strands per cm., the lump charcoal sample contained 5046 bacteria per cm. and 86 fungal strands per cm.
The conclusion was an extension of the set two conclusion but also showed that compost teas sprayed on substrates was the most effective method of increasing biological life colonization in charcoal.
This was extrapolated to conclude that the same would be true for soils treated in the same manner.

Over all the waxes and petro products used in the manufacture of the "match lite" briquette prevented growth of microorganisms.
The binder agents used in the manufacture of the "regular" briquettes, while having a stunting effect, did not completely prevent microorganism growth and occupation when compared to the match lite briquette.
The lump charcoal showed the most microorganism life with all establishing colonies within the pockets and along the smooth surfaces of the charcoal along with fungal hyphae extending strands from pocket to pocket and over the smooth surfaces of the lump charcoal.
It is apparent from this experiment that the charcoal found in soil called terra preta, found in the amazon basin, is indeed part of the reason for plant growing to be able to sustain a large population in that area, by sustaining large colonies of not only bacteria but strands of fungal hyphae.


Redhawk

(we did a second series and found that briquettes are better at sustaining molds than bacteria or fungi after a weathering period of 30 days green molds began to grow on the surface and penetrated into the compressed charcoal powder of the regular briquette, the match light sustained a yellow mold that was pathogenic)

Thanks, kola Redhawk. That's really awesomely detailed.

In your opinion, then, would you say that the mechanisms exist in nature to deal with potential contamination in a garden setting? What would you do to optimise the soil's remediative capabilities? Mulch, mushroom slurry, and compost extract? Or should potentially contaminated dust be avoided at all costs?

And what do you think will or won't be safe to eat coming out of such a garden?

-CK

Remediation can be done with both compost teas and mushroom slurries (oyster is one of the best).
Food safety would be most dependent upon when it was planted in comparison to the tea and slurry addition use time.
I like to give the microbiome around three months to get established and start working away if possible.
The fast plants are going to be the most vulnerable to contaminate pick up, radishes, kales, lettuce, and other greens are going to pick up contaminates faster because of their growth pattern (shallow root, quick growth).

Root vegetables should be fine as would any other long term to harvest plants, the mushroom slurries will give the roots some protection from ingress of contaminates.

Those are all first year or first season precautions, once the microbiome is growing, the amount of possible contamination gets less and less, it is a time line thing, usually the second year finds mostly clear conditions in my experiments and experience.

Thanks Redhawk and CK, very valuable information from you guys, thanks again.

I guess I can distinguish natural charcoal from briquette by a microscope. Their production process is different and also initial materials. So their dusts might be easy to distinguish. My guess is that briquette would have round edge dust and natural charcoal will have sharp edges. A good magnifier might also get the job done. I don't have a microscope at the moment, so that's a bummer.

Chris Kott wrote:So I suppose what you will be looking for is fragments of those formed briquettes that contain petroleum binders and waxes. If the "dust" is free of obvious pieces of briquette, you're probably in the clear.  

Refering your quate Chris, I searched how briquette is produced and found a nice website-resource. Here is the link How to Make Charcoal Briquettes: Ingredients and Composition. So ingredients are:
"   Heat fuel - wood charcoal, charcoal fines, mineral carbon, coal, biomass, etc.
   Burning speed – sodium nitrate and waxes. Sawdust can also be used.
   White Ash Color - Calcium carbonate, lime or limestone
   Binder – starch. Cement, kaolin, ball clay can also be used
   Press release – use borax
   Filler – for adulteration use silica, clay, soil, etc"
Frankly my chemistry and biology knowledge is limited. I guess the easiest way to distinguish is to identify either sodium nitrate/waxes or borax. They say (in the link) borax is not a must, it is required for rapid production. Sodium nitrate, on the other hand, releases oxygen speeding up the combustion process. So it is required for quality. I made a quick search about how to distinguish sodium nitrate. It is very water soluble (yeah!) but hard to distinguish since sodium does not create colorful compounds. So I will go after nitrate. I ordered a simple nitrate test (for aquariums), so when nitrate-test is delivered I will mix some coal dust with water and test the water for nitrate. That is my current plan. Don't know whether it will work though. Additionally I will check for shape differences.

I think I made a poor choice for the title. It should be something like - how to distinguish/recognize/tell apart briquette and lump charcoal.

Sodium could be tested for fairly easily, you would soak the suspect charcoal in water, filter out the charcoal, retaining the water, evaporate the water then do a flame test with the remaining powder from the evaporation process. (same process of prep for the reagent test you ordered)
Sodium give off a yellow flame (use a propane torch so the flame is blue).
Calcium carbonate will fizz if you poured vinegar over a briquette and it fizzes, you know you have calcium carbonate.