Looking at the same book mentioned above (Modern Private Owner Wagons on British Rail), the ALG 9080-9099 series is shown in the accompanying table for "Bulk Cement Wagons, two-axle, vacuum braked" with TOPS code PCF (the only wagon type with that code). That table is reproduced below:
| Type | Number Series | TOPS Code | Builder | Date | Owner / Operator |
| Presflo | TC 8951 - 8958 | PCV | Butterley | 1960 | Tunnel Cement |
| Presflo | APCM 8601 - 8828 | PCV | Various | 1960-1963 | Associate Portland Cement |
| Cemflo | APCM 8301 - 8490 | PCV | Gloucester RC & W | 1961-1962 | Associate Portland Cement |
| Cemflo | APCM 8500 - 8594 | PCV | Metro-Cammell | 1963-1966 | Associate Portland Cement |
| Powders | ALG 9080 - 9099 | PCF | Interconsult, Sweden | 1965 | Algeco / APCM |
About the only mention I can find online of PCF wagons is in this interesting article -
https://glostransporthistory.visit-gloucestershire.co.uk/gloucester-rcw-and-bulk-cement-wagons/
Immediately after the Thirsk disaster, too, APCM hired a small batch of tanker-like Swedish built pressure discharge cement wagons coded PCF.
I had trouble finding any photos of these ALG 9080 - 9099 series wagons because I was searching for cement wagons, but they appear in the guise of ICI powders wagons on Paul Bartlett's site:
https://paulbartlett.zenfolio.com/algecopresflo
The LTSV website lists these as PCV-B -
https://www.ltsv.com/rd/design_detail.php?id=DBWN-PC007A and has links to diagrams which show the same (note these PDFs are large files):
Page 61 of this PDF -
http://www.barrowmoremrg.co.uk/BRBDocuments/BRPOWagons1Issue.pdf
Page 41 of this PDF -
http://www.barrowmoremrg.co.uk/BRBDocuments/Book300Part1Issue.pdf
However, the diagrams are undated and I don't think it would be particularly unusual for the code to have changed for some reason, perhaps due to brake modifications or being given the wrong TOPS code to begin with.
On those diagrams the "owners numbers" (pre-TOPS) are shown as 2486-2505.
I did find a couple of photos of these wagons in traffic, in books by David Larkin.
In "
Non-Pool Freight Stock 1948-1968" there's a photo of ALGECO 2497 at Poole in 1970 (which matches up with the owners numbers listed on those diagrams). The caption refers to the Swedish origin, mentions their "short-lived APCM hire" and says they had a Blue Circle symbol in addition to the Algeco logo. Given the date, that information fits in with your initial post about these wagons being hired in after the Thirsk crash.
In "Working Wagons Volume 2 (1974-1979)" ALG 9084 is seen at Larbert in 1976 on soda ash traffic from Oakleigh, in the same ICI Mond livery seen on Paul Bartlett's site.
In summary, I think those ALG 9080 - 9099 series wagons must be the PCF wagons under discussion - the Modern Private Owner wagons book is fairly comprehensive for wagons in use from 1976 onwards, and there are no other 2-axle powder / cement tanks listed with that code. David Larkin's photo of one in Blue Circle use in 1970 is the only picture I can find of their use in cement traffic, but only a small number were built compared to the other Cemflo types so it's not that surprising, especially if their use on cement traffic was fairly brief before moving on to ICI. David Ratcliffe says the wagons remained in use until 1983.
Edit: Considering this is the nostalgia forum, it's worth mentioning there are some great shots of the well known Cliffe - Uddingston cement train on flickr. I can't see any of the PCF wagons in these formations, but the other Cemflo wagons look very good behind a green crompton on the east coast...
https://www.flickr.com/search/?text=cliffe+uddingston
