People always complain about how slow factorization is. 615 Ingots/hour isn't too bad.
Then again, on this scale you might as well use gregtech anyway!
Edit: I'll try to give a quick walk through of how my setup works since the OP was really asking for that. I'm using 1.4.7 with Redpower, but only for the mixers, and I'll explain an alternative setup that should work for 1.5.2.
First step: send your ore into some grinders at the top, pull from the side. Factorization only works with iron, copper, tin, silver, and gold. You'll get some "dirty iron gravel" or whatever ore you put in.
Second step: send your dirty gravel into mixers. Mixers only have 4 slots so it's easy to overflow if you don't regulate the input correctly. Hence I'm using redpower regulators here. The top output bus outputs water buckets that constantly refill elsewhere with a deployer. The level emitter turns on when there's no gravel left. The bottom output bus emits the gravel. The regulator emits a redstone signal when it's jammed, that is sent to the bottom output bus to turn it off. Excess gravel/buckets go into the interface at the top and get recycled into the output buses.
Note that you'll probably want a mixer for each type of gravel to avoid overflow. It's just so much cleaner this way.
The alternative to this method is to output all your gravel to a chest next to a mixer, and have a golem keep the mixer stocked with one gravel and one water bucket. This prevents overflow and doesn't require Redpower.
Third step: slag furnace. Same setup as the grinders, except that slag furnaces need furnace heaters next to them instead of a simple lead wire connection.
Final step (the most difficult): crystallizers. If you have enough resources to saturate one or a couple of crystallizers and don't care too much about speed you can use a setup like the one below. Input reduced chunks through the side (this is different from the other machines!) and pull from the top. Crystallizers need furnace heaters as well.
If you want to do the most and crank up the speed of ingot production, you can use routers. You need one router for each input slot of the crystallizer. There's no way around this. No other method will equally balance the chunks. Additionally, you need a router to send to all the other routers, and a router to pull from each crystallizer. The router sending to routers needs a machine filter set to item routers, there's no other way to access a routers inventory. The extracting router should have a machine filter set to crystallizers or an item filter set to crystalline iron/gold/whatever, but it's not necessary. Some of the chunks will mistakenly get sent to the pulling router but they'll just get recycled back into the system so it's okay.
The right 5 routers are set to slots 0, 1, 2, 4, and 5. The left top one is the input router and the bottom left is the extracting router.
That's it! I didn't think I'd end up writing this in-depth of a guide for factorization but I just finished building this recently and this was the perfect opportunity to
brag explain how it works.
