Under certain operating conditions, an emulsion of an acidified unfiltrable tarry bottoms stream from a reactor for the chlorination of ethylene to 1,2-dichloroethane can be demulsified and separated in a phase separation tank. The presence of FeCl.sub.3 in an amount more than 5 ppm Fe in the separated organic waste, fouls the reboiler and lower internals of a "heavies" column in which the separated organic waste is concentrated, and deactivates the catalyst in a Catoxid fluid bed reactor in which the concentrate is burned. By maintaining an iron salt chlorination catalyst in a concentration which results in 2000 ppm to 4000 ppm of Fe in the HTC reactor bottoms, and operating the HTC reactor at a temperature in the range from about 90.degree. C. to 120.degree. C. and a pressure in the range from 9 psig to 12 psig, an unfiltrable reactor bottoms drawoff is produced which may be acidified without forming an emulsion. Formation of an emulsion is avoided by mixing each volume of the HTC bottoms drawoff with at least 50 volumes of dilute aqueous HCl in a concentration range from 2 to 4% so as to demulsify the emulsion into aqueous acid and organic phases. The mixture is gravity-separated in a phase separation tank by decantation. The lower layer (60-70% by wt EDC, the remainder being heavies) is concentrated by recovering EDC overhead and producing a bottoms concentrate in which the Fe is present in no more than 50 ppm. The concentrate may be economically disposed of in a Catoxid reactor using a support-free gamma alumina catalyst found to be highly sensitive to iron.