Help with chimney?

[MaSa1976]

Hello!
My name is Mathias and I have a small question. In the chimney wall down in the basement, there is a hatch that the chimney sweep removes soot from and it has now fallen off because the material around it has come loose, so I wonder if anyone knows how I can secure such a thing and which material(s) to use?
Grateful for answers.

Best regards,
Mathias

 

[cheetah1]

Refractory mortar I would spontaneously guess. Or not guess, because that's what it is, but the preparation work can perhaps be more or less extensive.

 

[Roundup]

Remove loose render around the hole in the chimney wall and on the soot hatch. Mix masonry mortar C (available in ready-made bags at the hardware store where you only add water), but be sparing with the water so that the mortar becomes sticky and moldable instead of runny. Dampen the area you are repairing with a coarse brush, sponge, or similar. Apply enough render so you can finally press the soot hatch in with a good fit. If there are small holes in the soot hatch frame you can insert nail pieces there, otherwise, it should still hold. Let it "cure" for a couple of days, then it should be fine. A bucket and trowel are good to have.