are predicated on but not limited to the volatile makeup characteristics and chemical makeup of the feedstock the treated coal from the first stage is transferred into the second chamber of the retort in this second chamber the temperature of the material is elevated to about 900 1100 u00b0 f for example about 1000 u00b0 f in this second stage the feedstock relinquishes the majority of its volatile matter i e greater than 80 by weight of the volatiles that are removed are removed in the second stage this second stage is important in that it requires a carefully controlled atmosphere mixture of liquid hydrocarbons and processed nitrogen the second stage of the process is where the feedstock is most likely to be u201c shocked u201d into a u201c face powder u201d the coal after exposure in this second chamber s has survived the negative characteristics normally associated with this heat induced u201c shock u201d for some end uses the material that completes this second stage of the process would satisfy the specifications of some end users when this situation occurs the second stage treated material is collected and cooled by exposing the coal to a dry cooling gas which is typically substantially free of oxygen the cooling gas usually has moisture content of less than 1 by weight the atmosphere in the second chamber is very carefully monitored measurably supplemented and managed with conventional gauges that are installed in the heat chamber s it is found that the coal typically undergoes at least some agglomeration at temperatures between 900 u00b0 f and 1100 u00b0 f and particularly at temperatures above 1100 u00b0 f for this reason it is preferred to keep the temperature in this stage of the process generally less than 1100 u00b0 f the coal is retained.