Contracts all signed... Let's assume all contracts alluded to have been signed and are valid. Whew... Let's assume that the deposit has even been provided... Whew. So, what's the issue? Well, the devil is in the details. Contracts have terms and conditions required to be met for the successful execution of the agreements. We won't know what the terms and conditions of the various contracts are for completely valid business reasons. Deposits, when required, are often held in escrow by a third party pending agreed conditions being met. In the case of the Drosrite contract the escrow agent, if required, might be a bank. Many contracts include provisions for cancellation. For example, if you're selling your home the contract often stipulates the closing will be conditional on the buyer accepting the result of a home inspection, able to confirm financing, possibly completing the sale of their current home, water snd soil tests... etc, etc... Th sale is usually recorded when the closing occurs and the funds actually change hands.
So, we just don't know what the risks are. The smelter has a contract with Radian, who have a contract with Drosrite Internstional, who have a contract with PyroGenesis. When PyroGenesis has actually deposited money we can be confident a sale has occurred.