Not likely, and not a good idea.
Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
There is a definite possibility that the two kits will not play well together.
Ryzen depends on fast ram. Your suggestion would result in running at 3200 speed.
How much ram do you need?
If 32gb will suffice, buy a 2 x 16gb kit of 3600 speed that closely matches your current ram.
You will get a guaranteed 32gb. If the old ram plays nice, you get 48gb.
If not, sell the old ram or keep it as a spare.
Ram is cheap enough, if you can use lots, then perhaps a 64gb kit would be best.