Anthracite AS (Pea) 6-13 mm for Automatic Boilers

Anthracite AS (pea) 6-13 mm for automatic boilers with auger and retort burners: no slack, 25 kg bags and big bags, batch test report, trial bag, delivery.

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Anthracite coal AM (small) 13-25 mm in 25 kg bags

bag 25 kg size 13-25 mm

565 UAH / bag 22 600 UAH/t
in stock
Order Details
Anthracite coal AS (pea) 6-13 mm in 25 kg bags

bag 25 kg size 6-13 mm

565 UAH / bag 22 600 UAH/t
in stock
Order Details

An automatic coal boiler with auger or retort feed is fussy not about the grade but about the size fraction: each lump has to pass freely through the auger and settle evenly in the retort. The standard for these boilers is anthracite AS (АС, "pea") 6-13 mm: it does not jam the auger like AM 13-25 mm, and it does not cake in the burner pot like slack below 6 mm. A 200-300 kg hopper lasts 3-7 days without anyone touching it, and anthracite leaves less ash than any other coal.

Which boilers. Auger and retort burners from Retra, Kotlant, Heiztechnik, Defro, Galmet, Mars, Zota and similar makes designed for "eco-pea" coal or anthracite; some models also accept AM 13-25 mm, so check the burner manual, which states the maximum lump size. Anthracite AS also works in boilers designed for bituminous "eco-pea" coal, but the burner has to be re-tuned: anthracite burns longer and needs more air.

What matters in a batch. Slack (below 6 mm) of no more than 10%, otherwise the fines cake on the retort and put the burner out; moisture up to 8%, so the auger does not clog; ash content of 10-15%, with no rock. These figures are in the batch test report, which we send on request before payment.

Packaging and buying. 25 kg bags are handy for topping up the hopper, big bags of about a tonne suit a warehouse with a forklift, and bulk is available on request for boiler houses. Before ordering a tonne, we recommend taking a trial bag by Nova Poshta and running it through your burner: within an hour you will see whether the fraction feeds properly and how the ash behaves.

Price per tonne and per bag - Anthracite AS

Current prices for anthracite as (pea) 6-13 mm for automatic boilers, updated 01.10.2026. Prices include VAT, delivery not included.
Type / grade	Packaging	Unit price	Price per tonne	Note
Anthracite AS 6-13 mm (pea)	25 kg bag	on request	on request	40 bags per tonne
Anthracite AS 6-13 mm (pea)	big bag ~1000 kg	on request	on request	on request
Anthracite AS 6-13 mm (pea)	bulk	on request	on request	for boiler houses, on request
Anthracite AM 13-25 mm (if the burner manual allows)	25 kg bag	on request	on request

Ask our manager for an exact delivered price to your region: it depends on volume and distance.

Graded, screened coal One grade and one size per bag. No more than 10 % fines, as DSTU 3472 requires.
No dust or rock Only what burns goes in the bag. Ash and moisture of the batch are in the test report.
Trial bag via Nova Poshta Test the fuel in your boiler before buying a pallet or a tonne.
Check weighing Weigh any bag in front of the driver or at the post office. If it is short, we top it up or refund the difference.
Pay on delivery No prepayment for retail orders. Businesses pay by bank transfer with VAT under a contract.

How much coal you need per season

Enter the area, insulation and region to estimate heat demand, tonnes, bags and pallets. Add the price per bag to see your winter budget. The estimate is approximate: indoor temperature, wind and the boiler can shift it by 20-30 %.

Bag → price per tonne

Sellers quote per bag, per pack or per tonne, but offers should only be compared per tonne. Enter the price and weight and we will work out the price per tonne and how many bags make a tonne. It also works the other way: enter a price per tonne to get the bag price.

How many bags per tonne and how much a pallet weighs
Packaging	Per tonne	Pallet
15 kg bag (pellets)	66.7 bags	65-70 bags ≈ 1 t
25 kg bag (coal, agro pellets, peat)	40 bags	40 bags = 1 t
30 kg bag	33.3 bags	-
40 kg bag	25 bags	-
50 kg bag	20 bags	-
10 kg pack (briquettes)	100 packs	96 packs = 960 kg
Big-bag	≈ 1 000 kg	-

Questions and answers

Which coal suits an automatic boiler with an auger?

Anthracite AS 6-13 mm is the standard fraction for auger and retort burners. Some models also accept AM 13-25 mm or bituminous "eco-pea" coal of 5-25 mm; the maximum lump size is stated in the burner manual. Large coal such as AO and DG 50-100 mm is not suitable for an auger.

Why does the burner go out or the pot clog with clinker?

There are three causes: too much slack in the fuel (the fines do not let air through and cake), too little air for anthracite (the burner is set up for bituminous coal), or too long a pause in standby mode, so the bed has time to go out. Graded AS with no more than 10% slack and the right air supply solve the problem in most cases.

Anthracite AS or bituminous "eco-pea" coal?

Anthracite gives 20-25% more heat per kilogram and produces almost no smoke or soot, but it ignites more slowly and needs more air. Eco-pea coal is easier to set up, but it smokes and cakes more often. If your burner allows anthracite, it usually works out cheaper per kilowatt-hour.

How much AS does an automatic boiler use?

An insulated house of 100-150 m² needs 3-4 tonnes per season, i.e. 120-160 bags or 3-4 big bags; in frosty weather, 15-25 kg a day. A 250 kg hopper lasts a week in average weather. The "How much coal do you need for the season" calculator on this page works it out for your floor area and region.

Do I need to screen anthracite before filling the hopper?

Not graded AS with up to 10% fines: they burn off in the retort. Screening is only needed for run-of-mine coal or coal that has got wet and stuck together. The percentage of slack in our batch is stated in the test report, and you can check it in practice with a trial bag.

Can I order a trial bag of AS, and is prepayment required?

Yes: we send a 25 kg trial bag by Nova Poshta, cash on delivery. It is the easiest way to make sure the fraction feeds through your auger before you buy a big bag. We take no prepayment: you pay on delivery; companies pay by bank transfer with VAT under a contract.

Simiachko, semechka, AS, eco-pea: is it all the same thing?

AS and "simiachko" (сім'ячко; Russian: семечка) are the same thing: anthracite of the 6-13 mm fraction. "Eco-pea" (ekogroszek) is the Polish name for small bituminous coal of 5-25 mm for automatic boilers; it is a different grade with a higher volatile matter yield. All grades are explained in the article "Coal grades AO, AM, AS, DG".

Before you buy: guides

All guides →

Why AS and not AM or slack

An auger 60-80 mm in diameter reliably feeds lumps up to 13 mm; the 13-25 mm fraction jams it from time to time or crumbles in the auger, increasing the share of fines in the retort. Slack and dust below 6 mm, on the other hand, do not let air through, cake into a "crust" and put the burner out within a few hours. AS 6-13 mm is the range in which the auger does not jam and the fuel bed in the retort stays well aerated. If the burner manual allows 5-25 mm, you can use a mix of AS and AM, but pure AS runs more steadily.

Tuning the burner for anthracite

Anthracite contains 2-8% volatile matter versus 30-40% in eco-pea coal, so it ignites more slowly and needs more air per kilogram. Typical settings: feed 8-12 seconds, pause 40-60 seconds in operating mode, fan at 40-60%; in standby mode, feed once every 10-15 minutes with a short blow-through, otherwise the bed will go out. Watch the retort for the first few days: if the embers "sink" and the pot is clogged with ash, there is too little air or too much feed; if coal is blown out of the pot before it has burnt, it is the other way round. Exact figures depend on the model, so fine-tune them with a trial bag.

Consumption and ash

For an insulated house of 100-150 m², an automatic boiler on anthracite uses about 3-4 tonnes per season, i.e. 120-160 bags or 3-4 big bags. An ash content of 10-15% means 300-600 kg of ash over the winter: boilers with mechanical ash removal need their ash bin emptied every 1-2 weeks, simpler ones every 2-3 days. Anthracite ash is dry, does not cake with the right air supply and can be used to grit paths.

Storage and filling the hopper

Keep AS dry: a wet small fraction sticks together and bridges in the hopper, and in winter it freezes in the bags. Store big bags on a pallet under a roof, and bags on a rack or pallet in the boiler room. There is no need to screen the coal before filling the hopper: graded AS contains no more than 10% fines, and they burn off in the retort.

For wholesale buyers and boiler houses

Batches from 5, bank transfer with VAT, a contract and fuel documents. Delivery across Ukraine.