The phrase "dust heap" refers to a pile of dust or garbage that is no longer useful or valuable. It is often used to describe something that is considered to be worthless or of little importance. Full definition
In the Victorian times there was a huge dust heap in the area which was a source of income. (treehugger.com)
There is the famous remark made by Tillich, in his Germanic English, to fellow theologian Langdon Gilkey towards the end of Tillich's life, «Vy, Langdon, am I so soon on ze dust heap of history?» (religion-online.org)
Paris advocates assert that, despite President Donald Trump's decision to pull out of the agreement, we face an inevitable transition to a multitude of new low - carbon energy technologies that will consign hydrocarbons — oil, natural gas, and coal — to history's dust heap. (fortune.com)