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After you've claimed your Bitcoin Cash, make sure you send it to a Bitcoin Cash wallet...not a Bitcoin wallet. If you send it to a Bitcoin wallet the Bitcoin Cash will be lost forever.
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bitcoin and bitcoin cash, and also bitcoin gold and all the possible future forks that are similar to these, use the same key pairs. it means a bitcoin address has the same private key as the bitcoin cash address.
in other words if you send bitcoin to a bitcoin cash address or vice versa, you can simply get the bitcoin cash private key, import it in your bitcoin wallet and have access to the coins on bitcoin chain.
although this is only going to work if you have access to the private keys and also as long as these different forks continue to use same keys. things may change in the future (like BCH doesn't have SegWit).
in case you send them to an exchange (a wrong address) it depends on the exchange service to bother recovering the funds or not.