0T---SCORIA

[JHOLLAND1]

my day job is forensic medicine
a current case involves mig weld injury --perforated ear drum--failed surgery
both legal and medical resources reference slag burns destroying ear drums--
not entirely appropriate terminology in circumstance of solid core gas shield fluxless wire electrode

legacy terminology for slag is scoria--two hundred years ago iron ore smelting produced one
ton of scoria for every ton of iron
huge quantities of scoria bricks were manufactured in the Midlands as pavers--indestructable
and in use today

 

[dalmatiangirl61]

Was the slag/scoria just poured into molds for the pavers? Or was there another process? Why did they stop making pavers, seems like it would be an additional product line.

 

[JHOLLAND1]

Was the slag/scoria just poured into molds for the pavers? Or was there another process? Why did they stop making pavers, seems like it would be an additional product line.

Englishman Joseph Woodward is noted as patent holder for scoria brick mass production--1869
key to making scoria brick was Woodwards rotary wheel containing 140 brick molds which completed
a full rotation in 2 minutes--molds were filled with liquid slag at an iron mill --two minutes in the mold sufficiently hardened
scoria to allow tipping onto conveyor which carried the still red hot form into annealing ovens for a 3 day soak
when removed from the annies--they were ready for use as pavers

scoria is 54% limestone--prior to use as pavers the product was in demand from farmers--field fertilizer

I referenced my two volumes on steelmaking--Carnegie Steel 1919 /US Steel 1964--the term scoria is nowhere to be found in either--slag being the only applicable identifer

 

[Asquith]

Thanks for that, Mr Holland. Very interesting.

I was aware that two firms had operated at my local iron and steel works to utilise the slag, selling it as fertiliser but also producing various items moulded from slag. This was evidently different to the pavers, which must have been cast directly from the molten slag. The firms had long gone when I started there, and I’m not aware of seeing any of their moulded products. They were called the Baltic Basic Slag Co and C. L. Stiff & Co.

Living nearby, I was occasionally treated to the sight of slag trucks being pushed up the incline of a railway embankment for the molten slag to be poured out for later crushing and disposal. The trucks were braked by a steel bar pushed through holes in the wheels. A long chain was connected to the loco and to the tipping slag pot. Pull and pour. However the slag occasionally formed a crust and wouldn’t pour, so increasingly vigorous applications of loco on chain were demanded, not always ending tidily.

One thing I do see in this part of the world is building blocks cast from copper slag. They were used for capping boundary walls, and even as facing blocks for houses. Production started, and possibly ended, in the 18th century. The blocks are often nowhere near the site of former copper works, but always near waterways used by vessels which traded with those places.

More information and pictures here:-

https://www.gracesguide.co.uk/Copper_Slag_Blocks

 

[Asquith]

Thanks to JHolland's extra information, I have turned up more about the production, including the tricky annealing process. One of the main producers was the Tees Scoria Brick Co.

This may be of interest, from the Shields Daily Gazette, 25 March 1896:-

The American steamship Miami, with a deadweight tonnage of 4,500 tons, arrived light the river Tees about seven o'clock on Sunday morning, and is now lying in the docks loading 2,500 tons of Tees scoria bricks. She arrived there trom Antwerp, and will sail on Thursday for Philadelphia, and thence on to Baltimore, her cargo being destined for that place. The sight of the Stars and Stripes is very unusual on the Tees, and indeed on this coast nowadays.

 

[L Vanice]

I recall a visit to the Saugus (MA) Iron Works and seeing a sort of peninsula extending along the river bank away from the furnace. Signage said it was the slag heap dumped there during the time the works made iron (1646-1670). This was a time when the local old growth forests promised a perpetual supply of wood for making charcoal and slag was just waste to be dumped anywhere one could easily push a wheelbarrow. The works was operated by British immigrants and designed to use British methods of the time, but using local materials. Product and supplies were hauled on small sail boats using the river and Atlantic Ocean to and from Boston. The site is amazing and well worth a visit to see authentic replicas of the furnace, forge and rolling and slitting mill.

Photo of the slag heap: https://goo.gl/maps/ZDbEgtwuLqMVi1mP6

Bronze model of the works, based upon archaeology: https://goo.gl/maps/bmZ8DR7P2mibz2fR8

National Park Service site: https://www.nps.gov/sair/learn/historyculture/index.htm

Larry

 

[Matt_Maguire]

Englishman Joseph Woodward is noted as patent holder for scoria brick mass production--1869
(snip)
scoria is 54% limestone--prior to use as pavers the product was in demand from farmers--field fertilizer

I referenced my two volumes on steelmaking--Carnegie Steel 1919 /US Steel 1964--the term scoria is nowhere to be found in either--slag being the only applicable identifer

scoria is not referenced in my US Steel 1951 book either. Worked for an outfit that built slag pot carriers in the 70's. They'd back up to a pit, dump the slag & then rotate the pot back up & let it free fall to knock the outer crust out. Very dangerous job... the show gets real good about a minute in the vid

Good luck,
Matt

 

[john.k]

We used to buy bags of crushed slag called "Black Beauty",a one use abrasive blasting medium.........was very effective on stuff like fibreglass epoxied to steel......you could see the thick resin being cut away by the sharp grit .....ten time quicker than garnet ............You can also buy crushed copper slag as a blasting grit.

 

[Drroaster]

My dad worked at Kaiser plant in Fontana ca in fabrication. we went there in the 70’s and the fields next to the 10 freeway were 100’s of feet hi I actually have a jar from when they closed. the auto club raceway is built on top of it