The manager of a quarry where a worker was crushed to death on-site in central Queensland has been sentenced to 18 months in prison for safety breaches.

Rushing to get a central Queensland quarry operating, against the advice of experienced contractors, was a key factor in the death of a young worker who was pulled into a conveyer belt, a court has heard.

Sean Scovell, 21, was killed after he became entangled in a running conveyor belt at the South Moranbah Quarry, north-west of Rockhampton in central Queensland, six months after the quarry was hurried into operation by managing director William McDonald.

McDonald, his company MCG Quarries and site senior supervisor Tony Addinsall were found guilty of multiple charges of failing their health and safety obligations following Mr Scovell's death.

The company, which is now insolvent, was fined $400,000 for breaching health and safety obligations. Mr Addinsall was fined $35,000, but no conviction was recorded.