lambda, if I understood Your question right You wanted to know...

lambda, if I understood Your question right You wanted to know how long does it take from feeding the ore concentrate into the kiln until run off kiln. My guess is as follows:
in cement production it needs 20 to 40min at a production rate of 1500t/day (Temperature ca. 1450°C; length of kiln 60m, dry process);
to prevent dust emissions they may feed moisturized concentrate and the length of kiln will be extended(in former cement production we used the wet process with length of kiln up to 120m);
as mentioned in another post I assume they will use silica lining which should not be heated above 573°C because of alpha/beta-transformation of quartz in solid state accompanied by a tremendous change in specific volume;
the acid baking process with sulfuric acid is assumed to run smoothly in a temperature range between 200 and 250°C, because at ca. 280°C the acid exists above its boiling point only as gas and at 450°C dissociates into SO3 and H2O;
with this in mind I guess that the kiln run time should be expected in the range of 24h which should be sufficient to crack the interesting solids of the concentrate and to transform them into water soluble salts(Sulphates).
The most time consuming process to get to final oxides or oxide mixtures is the step of separation/purification by liquid extraction techniques which have have to be repeated many times.