If you have an oxy/acet torch, sure, you can easily melt that amount at one time. I used to use a Hoke torch (with a rosebud tip) to melt gold almost without exception. Small volumes don't generally warrant a funace.
You'd use a melting dish (not a crucible) and you'd want to stir the lot well once fluid, so it's homogenous. Use a carbon rod to stir, and make sure it's held in something that doesn't conduct heat well, as it will get hot in a hurry. Carbon rods for stirring are readily available from jewelry supply houses, as are melting dishes. Make sure you pour to a mold that is well warmed (to prevent steam explosions) and well blackened (use an acetylene torch to do that), which will prevent the gold alloy from soldering to the mold (I'm assuming a cast iron mold, which was my choice).
I'm surprised that you make no mention of platinum. I refined gold for more than 20 years and handled a great deal of dental. While it doesn't all contain platinum, much of it does. You may or may not get paid for the platinum metals, though. All depends on where you sell, and how much is present.
Harold