If your coal safety certificate has been completed, it means that your business license covers the production and sales scope of this kind of products (because you need to upload the business license of the enterprise during the process of handling the coal safety certificate, and you can only apply for the business license after passing the coal safety certificate). Products with coal safety certificates can be produced and sold normally without a production license, but they can only be sold in coal mines without a coal safety production license. I also learned it from the telephone consultation of the Safety Standards Center.
If you want to sell your products to other industries, such as petroleum, chemical industry and metallurgy, you need to apply for a production license.
If your product belongs to general industrial products, you should apply for a production license. If your product belongs to measuring instruments, you need to apply for a production license to manufacture measuring instruments, so that it can be sold to other industries except coal mines. I have done this job, which is absolutely correct.