An association may be organized to engage in any activity in connection with the marketing or selling of the coal of its members or with the sampling, storing, processing, permitting, reclamation, or transporting of the coal or its derivatives; or in connection with the manufacturing, selling, or supplying to its members of machinery, equipment, or supplies; or in the financing of the above enumerated activities; or in any one (1) or more of the activities specified in this chapter.