It costs between $1 and $40 a ton to build, operate, and close a mine tailings facility. That is as specific as I was able to be when answering a question today in response to an enquiry from Australia. There is a surprising paucity of data out there on the cost of tailings management. We have details of salaries & wages. We know the compensation of mining company executives. We know how much it costs to engage and retain even the most expensive consultant. But we have no data-base on tailings costs.
There are many reasons for this mystery. First is that tailings management costs are site-specific. Second is that they are not very exciting—most folk want to know what they should earn, and care little about tailings costs. Third, nobody has set out to gather and publish the data. Forth, most mines probably do not know or care.
Maybe we should plead with the folk at CostMine to address this cost deficiency. Maybe CostMine could survey mines and ask them what their tailings costs are and publish the data to our edification & delight.
Failing that we are left with the old-fashion methods: list operations; list quantities; establish unit rates; and work it all out. There is only one man that I would trust to do it accurately. Contact me if you want his name.
Keep in mind that as in all mining estimating, you will have to attend to varying degrees of accuracy depending on the mine planning phase. It in prefeasibility, the accuracy is low; if in feasibility, the accuracy is reasonable; if in detailed design, the accuracy should be precise; if constructing & operating, the costs are actual; and if going to closure, well best shudder, pay, or say you are bankrupt.
I would guess that in a nice climate, the cost of conventional slurry, hydraulic fill tailings deposition is $1 to $3 a ton. Add $2 to $3 if the climate is arid and you have to desalinate or pump long distances. Get involved in thickened tailings and the promise (false) that it offers, and you must add $3 to $5. I do not comment on paste tailings on surface, for I do not believe it is viable at any cost.
If you choose to filter press and dry stack, you are in for $5 to $10 a ton. But consider the cost savings associated with a lesser water cost. And beware the potential need to add cement to control moisture content and get a required strength. Cement is expensive.
And if you go for polymer amendment remember the sky is the limit. Polymer amendment works—that I can attest—but even the consultants are costly.
In conclusion, do not seek industry averages, for they are meaningless. Get a qualified cost estimator and work out the detailed costs.
Good luck and let us know what you conclude.