... ), technology is very important, we had been doing oil refining for ten years, actually, have been experienced times of ... by-product, if it is made by plastic oil refining, it can be made of coal and brick. If ... it is made by tires oil refining, it is called carbon blackit is valued about 400 ... per ton in our country, if make it further process to 800-1200 meshit can be value about 4000- ...