Blockchain — is a technology which makes transparent business processes possible. Thanks to blockchain you can see where your money is going, as if you would personally take your money to the demining company and oversee their work. To make this possible a smart-contract is put in place.
In this smart-contract the parties agree to the terms, if the money is transferred, the mines must be cleared. If any of the parties don't perform their duties, the smart-contract is not executed.
In reality the chain of events would include accountants, finance specialist, bankers, payment aggregators, a smart contract does all this automatically.