A boatload of waste containing an amount of toxins come in. At the price of using up filters, a truckload of ash containing a smaller amount of toxins comes out

A boatload of waste containing an amount of toxins come in. At the price of using up filters, a truckload of ash containing a smaller amount of toxins comes out. And you get quite a bit of energy out of the process too. Sure, the energy you get out isn't worth as much as the materials and labour you put in. If that's a modern plant, you also recover metals from the waste - a roughly break-even process that allows you to recover material that was previously unrecyclable. The ash coming out at the end is orders of magnitude less voluminous than the input, uniform, powder and dry. The Internet claims this gets used in construction as bulk fill and road underlays, but I haven't seen any official materials about that. All in all the process is economically viable (especially when you have no cheap land to waste, but probably otherwise too, see the case of Sweden importing Italian trash) and seems strongly preferable ecologically.