Is it appropriate to request increased compensation?

I was recently assigned a specific set of tasks at work that the office manager usually handles. She is no longer going to be handling these tasks, they've been diverted to the HR department (which I head) and assigned to me as they are managerial tasks that cannot be delegated. This increases my workload by about 50% and as these tasks are time sensitive, will require me to dedicate an entire five-daywork week from the first of every month to them. This requires me to readjust my entire interview and hiring process schedule accordingly and decreases the number of potential employees I can see in a month. Is it appropriate to request an increase in compensation at this time? I am contracted to a 3% salary increase annually, this is not due to come around until November. Just looking for some professional advice. I have never done a request for increase outside of my contract so I am curious about others experience. Thank you!