I could spare an old walthers slag car kit. Not much but it is a start. Walthers slag cars seem to be hard to come by at present.
There are State Tool and Die kling style hot metal cars around.
http://www.toytrainheaven.com/.sc/ms/cat/HO Cars State Tool & Die Co--State Tool & Die
I'm currently moving house so I will have to get back to you in a week or so.
Just a brief look at blast furnace operations for now. Though the modelling books cover some operation, I had to find out a whole lot not mentioned in them.
OUTPUTS
We need to choose how big the furnace will be, as in what quantity of output will be produced. The walthers kit is a bit on the small side so a small amount seems appropriate. I decided to go for 150 tons of hot metal per heat. Given the walthers hot metal cars are about 150-168 ton capacity, these means one hot metal car per heat.
3 to 4 slag cars are needed for each hot metal car of this size. Given good quality ore, about half the weigh in hot metal in slag is produced. Given we are talking 150 tons of hot metal in a heat, then 75 tons of slag will be produced. Slag cars, like the walthers car, hold about 25 tons.
There should be a second hot metal car and a second set of slag cars to replace those cars taken away after loading. Slag cars need to be spotted fairly quickly as they need to be there in case extra slag must be taken off. Hot metal cars need lots of maintenance, especially for the brick lining, so visit the repair shop frequently.
A weigh bridge is the first detination visited by either car type, before proceeding to their destination. The hot metal cars will be weighed on the way back and inspected at that point. Then either cleared to be spotted back at the furnace or sent to the repair depo and the spare hot metal car used instead.
Other outputs are dust removed by hopper. There could be coke fines from the stock house to remove if you want. This stuff is often sent off to a sintering plant. One hopper per day is enough for a little blast furnace.
INPUTS
Inputs are well covered by modelling books on steel mills. But a quick rehash. For each ton of hot metal, we need 1.6 tons of ore (assuming good quality ore), 0.55 tons of coke and 0.30 tones of limestone. Given an output of 150 tons, we need 240 tons of ore, 82.5 tons of coke and 45 tons of limestone. Thats 6 movements with the ore transfer car (they often hold around 50 tons, thus 5 for ore, 1 for limestone) and 2x 50ton coke hoppers per heat. That would be 1x 50 ton hopper for limestone and 4x 70 ton ore hoppers, if materials are delivered by rail rather than ship.
Note ore hoppers are rarely used to deliver ore directly to the stockhouse. An ore bridge is used as the process of scooping up the ore can be done in such a way to mix ores (particular in relation to size of ore pieces). Sadly no commerical ore transfer car is yet avaliable. I'll be kit bashing a Grandline GE 35 tonner box cab, an old MDC ore hopper and some ST&D mill cars to make a transfer car.
GENERAL
There might be 3 to 6 heats a day. I plan on 4 heats a day. Given an operating session would be one shift (8 hours), that might be one or two heats per session. Crunching the numbers, we can now figure out how many cars of various types are needed. I'll let you calculate your requirements.
I mentioned one 8 hours worker's shift for an operating session. This leads into my promised operating session diatribe. I'll leave that for a later post.