atmosphere via a cooling device and a bag filter for example residue from the carbonized matter is removed as slag for recycling in order to detoxify asbestos a fusing agent needs to fuse asbestos at as low a temperature as possible and alkaline compounds have attracted attention as such fusing agents asbestos may be rendered into a powder form semi baked form or slurry form by heat processing at approximately 800 u00b0 c this thereby enables reliable decomposition of the asbestos which is detoxified by for example causing destruction of the fibrous form or breakdown of the crystalline structure of the asbestos calcium fluoride calcium carbonate calcium oxide sodium silicate sodium hydroxide or the like or a combination thereof may for example be employed as the fusing agent the carbonization furnace illustrated in fig2 may be modified according to its purpose namely in the carbonization furnace illustrated in fig2 the volume of carbonized matter obtained is comparatively large however this is since combustion ash inappropriate for use as carbonized matter is all removed together with the carbonized matter there is accordingly an issue of the volume of the gasification furnace 3 of the subsequent processes being larger than necessary moreover in cases in which there is a possibility of asbestos being mixed in with the waste the asbestos is detoxified by adding the fusing agent to the waste with this detoxified material also being removed together with the.