| 摘要 |
A method of thermographically separating lumpy feedstock comprises feeding the feedstock lump by lump, exposing the feedstock to microwave radiation, recording induced radiation, detecting a valuable constituent, comparing the weight fraction of the valuable constituent in a lump with the threshold value of the fraction, and separating the lumps into useful aggregates and worthless material from the comparison. Each lump of the feedstock is exposed to microwave radiation. Upon interruption of the exposure with the heat exchanging processes between constituents of a target lump being damped, the heating pattern often target lump is recorded wherefrom the mean temperature of the target lump is first measured and then the weight fraction of the valuable constituent in the target lump is found by the formula: Q= A/B where A = (TU-To)c and B is Uocr-Tu(cr-c)-ToC; then the condition Q e" Qnop is verified. Qnop is a threshold value of the weight fraction of a valuable constituent in a lump. Q is a weight fraction of a valuable constituent in a lump and TU is the steady-state temperature of a target lump. To is the temperature of worthless material, to which it was heated; and Uo is the temperature of a valuable constituent, to which it was heated. cr is the heat capacity of a valuable constituent and c is the heat capacity of worthless material. Where after, from the finding of the weight fraction of the valuable constituent, the lumps of the feedstock are separated into two streams: one stream consisting of the lumps where the valuable constituent is present in an amount that is less than a predetermined threshold value, while the other stream consisting of the lumps where the valuable constituent is present in an amount that is not less than the same threshold value.
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