operation oaxaca: transportation.

why nobody wanna do AMD into cement. (036)

Carlos Manuel Jarquín Sánchez
4 min readMay 9, 2024

this is carlos.

a lot happened over the past 1.5 months.

in a few sentences:

and yes, i got some setbacks.

that’s part of the process.

the train must keep going.

after speaking with government leaders in pennsylvania, consultants, and social enterprises:

i reached this conclusion.

the #1 reason why nobody has dared to try AMD into iron oxide for cement is…

transportation costs.

it’s too much…

but by how much?

so i went to the EPA files and found this.

i took a look at their data, and it shows how much it costs them for each dry ton.

but how much will it cost them to transport it per year???


the costs come from the distance from the AMD treatment site to the kiln/firing site to take it to the cement plants.

so it’s necessary to dewater sludge.

lowers the amount of weight… therefore reducing the cost of transport.

but less water means you also need to heat the kiln less than the typical 1450°C.

then again, adding iron-rich materials lowers the energy cost of the kiln.

but anything that requires high transportation/handling costs will not help.

basically, we do not want a short ton of this AMD to be like $100/dry ton… that’s way too high for other materials like limestone/calcium carbonate.

the answer.

everything is compiled here.

i took the dried sludge distances that each treatment site was willing to go to dump it at a landfill or farmalnd for soy, corn, or another crop.

then i took the average price per short ton of this waste.

p.s.: since this is a USA case, i am assuming the numbers are in short ton on the EPA paper.

note that this is sewage sludge. the economic costs behave similar to AMD.

if we extract the extreme answers from the data…

the average cost per ton is $35.411

the average mile distance is 6.4021

divide the avg. distance by the avg. cost, we get: $0.1807 per ton-mile.

then, we must multiply that by the miles we will travel to dump the waste.

then we multiply that with the amount of short tons we will transport per year.


and then there’s another method from this paper.

it says to calculate the cost of transporting per mile:

formula was:

TC = [PF x {(CAP)}^-1] x 2D

TC = transportation cost [cost per mile-ton]

PF = average market freight price per mile ($US/ton)

CAP = capacity of the truck was measured in tons (t)

2 = distance multiplied by 2… as it considers the round trip;

D = distance (km) … but also convert to kilometers.

in our case, we will omit to miles.

so i will prove to you in both methods that our cost-per-mile will be close to each other.


USA first.

so the cost per mile was $0.18

we will use from the EPA paper… york, pennsylvania.

the profit made from the sludge was visible.

one-way trip was six miles.

there was 1360 tons.

$0.18 x 6 x 1360 = $1468.80

profit generated was ~$1380.00

so not profitable.

but for the curious… the cost to operate the full plant is ~$98,960.00

cost per dry ton was $73.

too expensive.

BRASIL is next.

so we will use their formula:

TC = [PF x {(CAP)}^-1] x 2D

PF = two options: $73 or $0.18, let’s try both, y not?

CAP = 12.5 tons.

the 1968 diamond t. tank truck has a maximum freeway capacity of 12.5 tons.

D = 6 miles.

TC = [73 x {(12.5)}^-1] x 2*6

TC = $70.08

$70.08 x 1360 x 6 = $571852.80



now, let’s try with the offical one we made using the USA sample.

TC = [PF x {(CAP)}^-1] x 2D

everything stays the same except PF.

that is now $0.18

this is the cost-per-ton-mile in USD… as what the formal definition is.

TC = [PF x {(CAP)}^-1] x 2D

TC = [0.18 x {(12.5)}^-1] x 12

TC = $0.1728


ok, now, if we try to multiply the tons used per year and the miles…

$0.1728 x 1360 x 6 = $1410.048

profit was ~$1380.00.

still not enough.

but hey, the brasil method came close.

USA got us $0.180 with those specific averages.

BRASIL with their technique got us $0.1728 with their formula.

so close enough.

and we can see that we will need to lower costs from both the average price per ton and cost per mile-ton.

price per ton must get lower than $73/short ton.

it should be at least $25/short ton.

if there’s a lot of AMD… that can be a lot of short tons of AMD material.

so make it affordable to the cement company.

if they spend on something that will save them money in the long run, good.

they’ll spend.

otherwise, no.

so i will make another proposal in the following days.



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