Yeah, you can, but you gotta be careful—it's easy to burn out the motor. This drill has two speed settings: Low (0-500 RPM) and High (0-1900 RPM). For thick stuff like mortar, you absolutely need to use the Low speed setting.
Here's the deal: Don't just jam the mixer in and lean on the trigger. Start slow, let the tool do the work. If the speed comes down extremely or the tool bogs down, you're overloading it. Reduce the load or stop immediately to avoid damaging the tool. Use a paddle mixer attachment designed for the chuck size.
Heads up: Hold it with both hands—one on the grip, the other supporting the bottom of the battery cartridge to control the twisting action. And never wear cloth work gloves; they can get entangled in the moving parts.