[SOLVED] Phurnacite in a dual-fuel stove Solved

Yes, Its hard to maintain complete combustion with Phurnacite, especially in an open fire

Why not? Mix it with other stuff. Its basically sand.

I wont tell if you dont. It's about as radioactive as low level nuclear waste

My late mother used to burn Phurnacite in an enclosed 'coal fired' stove for DHW and CH, many years ago (late 1960's early 1970's). Not dual-fuel. My understanding is that Phurnacite is a processed form of anthracite, a very high carbon content form of coal, circa 90% carbon. I'm a little surprised you get a lot of ash, and that it doesn't stay 'in' overnight. Hers certainly did. Perhaps it was different then. Do you have too much air, or perhaps too little? Perhaps Phurnacite isn't what it used to be.

Where I was staying over Christmas they had a dual fuel burner. I don't know what solid fuel they were burning but came as uniform coal like nuggets.

The burner had different settings for logs and solid fuel. This particular burner had a control at the back that restricted air flow and had to be closed down for the solid fuel. It also had front controls for normal air flow but the instructions also suggested that these were left in the throttle down positions for coal.

Some observations :- Logs burnt quickly but a large load of coal nuggets burnt for 6 to 8 hours.

For the same length of burning the coal nuggets produced 3x as much ash as the logs. If coal was used overnight the ash pan always had to be emptied whereas it could be left for 3 or 4 days when only burning logs.

After 6/8 hour of coal everything was consumed but the skeletal remains of the nuggets could still be seen. They turned to a fine ash when poked with a poker. After 8 hours there may have been a few glowing embers underneath the ash and with the addition of a few morning sticks (softwood kindling) the fire could be started again - but mainly with logs.

This was rural area where large piles of medium size nets of morning sticks could be found at the local stores @ £4/net.

Where I was staying wood ash went on the compost heap and coal ash in general waste. However when there was free green waste collection all ash went it the green waste recycling bin. The council this year starting charging extra for green waste and have many have decided to not take the service. In a area where many people have log or dual fuel burners I do wonder how much extra ash in going to be added to the general waste landfill bill.

that probably depends on the grade of the coal/smokless fuel

Cheap s*it with a high proportion of silica will leave a lot of ash.

If you have a garden space its easy enough to add both sorts of ash to it. Fly ash will lighten up clay soils a bit and may make them a little more acid. Wood ash simply adds potassium IIRC.

coal ash is pretty much wood ash + mineral oxides, especially silicon and iron

Thanks for all the helpful replies. It's better to ask here for those with experience than read umpteen web pages! By the way, it seems that up to 1990 Phurnacite was made from crushed coal bound with coal tar pitch, and formed into nuggets which were then baked in an oven. How it is made now I have no idea. I would assume that it basically has the ash content of pure anthracite coal. There were changes in the law relating to smokeless fuels in 2023, but the Phurnacite I have is more than 12 years old.

The much lower burning temperature than wood, but much longer burning time, is what's proving difficult to get used to. At present I am allowing the fire to go out overnight, but if we get a prolonged cold spell during both day and night I'll keep it going.

Doesn’t the term dustman which is still used by a lot of people originate with collecting coal dust IE ash from households once the housing of the industrial revolution was built ? With hardly any packaging ,food not being wasted and the make do and mend of and handing down of clothing being a way of life for many there wasn’t much else to throw away. So throwing it in the dustbin has a long pedigree.

About 15 years ago I found myself short of sand to build the base for a small greenhouse, using some coal ash I had awaiting disposal saved going to get some, no idea what the ratio was and just mixed it till the mix slumped right. Set nicely hard and is still in place with no deterioration.

GH

Google pozzolan. Ancient Rome's answer to portland cement made from volcanic ash. Also 'cinder blocks'

Phurnacite is basically anthracite dust with a fixing agent, like molasses to form into the oval shapes.

We have a Morso Dove multifuel stove we've used for 25 years as our main heat source. We live at 1200 feet above sea-level in the exposed, very rural, north Pennines. The stove works wonders and heats the entire house (no boiler attached to the stove - room heater only)- with all room doors left open inside. Wood (kiln dried) used from early autumn evenings until November and then anthracite burnt 24/7, without having to relight the fire for many weeks. Just empty the ash pans and riddle daily, put on some more coal. Anthracite burns very well, on a low heat setting, all day and night. Permeates heat throughout the whole cottage. Anthracite has far less ash then phurnacite as it's 'naturally' smokeless. We empty the ash into a metal container, and when it cold put it in the general rubbish wheelie bin. From about March to April we burn only wood in the evenings again. Durign the summer we generally don't have a wood fire, but make one up jsut incase there's a particularly cool evening.

Phurnacite is a pain. The ovoid shape means it is difficult to stack as the top nuggets keep rolling off unless placed very carefully. Also, I only get away with riddling once, as the smaller pieces of partially burnt nuggets fall into the circular grill - but not right through it - and jam the riddling mechanism.

In our last house - best part of 50 years ago - we had an AGA - it used Phurnacite. Absolutely no problems with it. But thats the sort of item it was designed for - not a "multifuel" device.

I've run coal, coke, anthracite and Phurnacite in Agas. Anthracite best IMO, with coal to get it started - and some wood. Phurnacite IIRC was simply expensive.

Thankfully I now run oil. A match to get it started...

With Phurnacite you only needed to fill it once a day.

Same with anthracite or steam coal.

not what I found, but when I came to remove said AGA, I disovered it was a second-hand one and hadn't been properly put together! There might be a connection.

Phurnacite was simply anthracite dust glued together with tar.

That's what I understood, but where does all the ash come from? Anthracite produces little ash from what I've read, and surely coal tar can't produce /that/ much ash when it burns. The ash is much heavier than an equal volume of wood ash too, so must have a high mineral content. Silica/silicate of some sort?

Could it be cement dust? Though Phurnacite has been around for Decades it is likely that like most things the manufacturer is always trying to save on production costs and instead of having a totally flammable binder like the tar or molasses of old may have substituted some with cement dust in the binder.

GH

I was thinking that myself. On my one and only trip down a deep coal mine, the floor was covered in dust. Coal dust and something remarkably silica like. I think they said it was for safety.

Phurnacite is obviously whatever was left over that no one had a use for. Glued together and sold. Like chipboard

Coal can have a lot of other minerals than carbon and organics. Its likely that phurnacite doesn't bother to even try and extract them

It is slightly more expensive than anthracite. Ho hum...

Where can you get anthracite from nowadays?

Aberpergwm Colliery is the only producer of high grade anthracite in Western Europe, but all its output (I think) went to the Tata Steel plant next door. Not too sure what happens now, since that plant closed a couple of months ago.

To return to the original question, maybe the manufacturers of Phurnacite substituted a poorer grade of coal - back when anthracite first became scarce.