293.050.  Hours of work — safety rules — posting of law and rules. — 1.  It is unlawful for any operator engaged in mining or prospecting for minerals to work any employee at such labor longer than eight hours in a day of twenty-four hours, without his consent, and it is declared that eight hours constitute a day for any employee engaged in such labor.

  2.  It is the duty of operators and employees to comply with the provisions of this chapter and to cooperate with the division of mine inspection in carrying out its provisions.  Reasonable safety rules and regulations for the protection of employees and preservation of property that are in harmony with the provisions of this chapter shall be complied with.

  3.  For the purpose of making known the provisions of this chapter and the rules and regulations authorized by this chapter, an abstract of the law and rules shall be furnished by the director and posted in conspicuous places at or near mines where they may be conveniently read by the persons there employed.  It is unlawful to remove or deface such abstract, and so often as they become obliterated or destroyed, the operator shall cause them to be renewed.