Wigan Album

There was a Miners Strike in 1912 so I would think this is the time the photograph was taken.

I remember helping my uncle a few times making briquettes out of coal slack, this is copied from the link below,
'I use a plasterers trug,big and round.Tip in 6 measures of coal dust.Add 1 measure of sawdust.Mix.I use rubber gloves and get my hands in there.Add 3/4 measure cement.Mix thoroughly. Then add some water.It needs to be just the wet side of dry. This one you will have to play with.Needs to stick together when squeezed.Remember that you can put it in but can't take it out! Mix it well. I use a 3" flowerpot as a mould. You choose yours.Pack the mix well in and firm it.Tip it onto a board,let it dry.They will burn for an hour. This takes me about 15 to 20 minutes,and uses waste.I always have cement in,and the sawdust is a by product of the chainsaw ,as we burn wood too.'

Though we never used any sawdust and just mixed the slack with cement with some water until damp and moulded it into briquettes in a child's sand bucket, turned them out and left to dry, and they must have burned okay as he would make them whenever there was a lot of slack left in his coal bunker. Though I suppose if you do have any sawdust it would mix in with the slack and cement and help in throwing out some heat when burning.

https://www.uk-preppers.co.uk/forum/viewtopic.php?t=16139#:~:text=6%20measures%20coal%20dust%2C1,It%20works.