Healing time varies based on age, health, complexity and location of the break as well as the bone displacement. For adults, a minimum of 2-6 weeks of sling immobilization is normally employed to allow initial bone and soft tissue healing, teenagers require slightly less, children can often achieve the same level in two weeks. During this period, patients may remove the sling to practice passive pendulum Range of Motion (ROM) exercises to reduce atrophy in the elbow and shoulder, but they are minimized to 15-20 degrees off vertical. Depending on the severity of fracture a person can begin to use the arm if comfortable with movement and no pain results. The final result is to be able to have full range of motion with no pain, therefore, if any pain exists it is best to allow for more recovery time.
Depending on severity of the fracture, athletes involved in contact sports may need a longer period of rest to heal to avoid re-fracturing bone. A person should be able to return unrestricted to any sports or work by 3 months after the injury
http://en.wikipedia.org/wiki/Clavicle_fracture#Prognosis
Surgery
Surgery may be required for a fractured collarbone if the bone has broken through your skin, if it is severely out of place or if the bone has broken into several pieces. Broken collarbone surgery usually includes placing fixation devices — plates, screws or rods — to maintain proper position of your bone during healing. Complications are rare, but can include infection and lack of bone healing.
Clavicle fractures should heal completely within 12 weeks, but the pain usually subsides within a few weeks. Often patients are back to full activities before 12 weeks has passed, especially with younger patients.
When can I return to my sport or activity?
Return to full participation should be avoided until your clavicle fracture has healed and you can perform all skills and other requirements of your sport without pain. To return earlier is to invite further injury, making subsequent fractures more likely. This is especially true when the sport involves heavy contact, such as in football, hockey, or rugby.
Generally, the athlete who wishes to return to a contact sport should expect to be out of action for 6 to 12 weeks. Again, the time to return to full activity depends on the dedication toward your rehabilitation program.
Remember: the goal of rehabilitation is to return you to your sport or activity as soon as is safely possible. If you return too soon you may worsen your injury, which could lead to permanent damage. Everyone recovers from injury at a different rate. Return to your activity is determined by how soon your clavicle fracture recovers, not by how many days or weeks it has been since your injury occurred