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Carbon losses (3 replies and 3 comments)

Irene Ibz
3 weeks ago
Irene Ibz 3 weeks ago

Hello,

I work in a plant where there are a lot of carbon losses of about 7 to 9 tonnes per month.. Now I have been given a project to minimize the carbon losses and of course I know carbon is lost due to attrition losses in the agitators, kiln, due to screen leakage and so on but specifically I need to know how to quantify these losses and put them into numbers.. thank you!

Jorge Ganoza
2 weeks ago
Jorge Ganoza 2 weeks ago

It is well known that active carbon is lost by attrition and abrasion during the adsorption process, and also when is pumped, transported, screened, burned and regenerated. The first step is to select the right activated carbon, in your case abrasion tests should be included in the evaluation. Abrasion tests involve subjecting the sized activated carbon sample to a wear state. Dry and wet tests are necessary.

In your operation, you should follow the new carbon added in the circuit. You know the weight of the carbon added in the last tank. When that charge of carbon is loaded and removed from the circuit, you can determine the new weight. In this case you can estimate the losses in the adsorption circuit. The same approach can be considered in the next stages, desorption, regeneration, and screening.

It is important to evaluate your equipment. Make sure the speed and mechanical parts are correct. Your study should consider an historical information of the carbon losses to identify any possible change in any period.

Irene Ibz
2 weeks ago

Thank you so much Jorge! But what about screening?

Jorge Ganoza
2 weeks ago
Jorge Ganoza 2 weeks ago

After regeneration, the activated carbon is screened (e.g. 20 mesh) to remove fine particles. The oversize fraction is returned to the adsorption circuit. Considering the fact that you know the weight added in the last tank, you can determine the loss of activated carbon (undersize).

The last adsorption tank could be a potential source of losses if the screen installed in the tank is not correct. The presence of fine particles of activated carbon could pass through the screen opening. 

Irene Ibz
1 week ago

Thanks a lot.. I tried to do some abrasion tests but I doubt the results since the used carbon had high abrasion resistance than virgin carbon... how do u determine your abrasion tests plz

Jorge Ganoza
1 week ago
Jorge Ganoza 1 week ago

In order to perform the dry abrasion tests, 40-50 g charge of dried sized carbon is pre-abraded for ten minutes on a 1.0 mm standard brass sieve of 8” diameter employing a 20 mm stainless steel ball and a rot-tap sieve shaker. The oversize material is subjected to the same conditions for further 60 minutes. Then, the percentage ratio of oversize to total charge is the abrasion resistance,

Wear resistance = [+1.0 mm, oversize/(oversize + undersize)] x 100

Irene Ibz
1 week ago

Thanks a lot Jorge!


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