鉱滓[kousai] slag
残滓[zanshi] remains
油滓[aburakasu] oil cake (fertilizer made of oily vegetable dregs)
味噌っ滓[misokkasu] miso lees
燃え滓[moekasu] cinders

食べ滓[tabekasu] leavings of a meal
搾り滓[shiborikasu] strained lees (e.g. sake, tofu)
熔滓[youshi] slag
搾め滓[shimekasu] oil cake

化石燃料[kasekinenryou] fossil fuel
可燃[kanen] inflammable
可燃性[kanensei] combustibility
可燃物[kanenbutsu] combustibles
核燃料[kakunenryou] atomic fuel

再燃[sainen] recurrence
代燃車[dainensha] car running on substitute fuel
内燃機関[nainenkikan] internal-combustion engine
燃える[moeru] to burn
燃え移る[moeutsuru] (of fire) to spread