GB815619A - Improvements in or relating to the separation of scrap steel from slag - Google Patents

Abstract

815,619. Magnetic separation. NEWELL & CO. Ltd., E., and HOWDEN, P. July 25, 1957 [July 27, 1956], No. 23211/56. Class 117 A method of separating stray or scrap steel from basic slag comprises feeding the slag in a thin wide stream over a magnetic separator of corresponding width, removing the slag that has passed the separator by a reversible conveyer, interrupting the feed until the conveyer has discharged all slag that has passed the separator, cutting off the separator, removing the collected steel thus released from the separator by reverse operation of the conveyer, and then resuming feeding of the slag with the separator in operation and the conveyer discharging in the original direction. As shown in Figs. 1, 2, plant for carrying out the method comprises a shoot 2 for receiving raw slag which is transferred into a wide base hopper 6 by means of a skip elevator 4, a pan or apron feeder 7 then feeding the slag in a thin wide stream to the inclined surface 8 of a multiple electromagnetic separator 9 Pieces of steel, or slag containing steel, are retained and the remainder of the slag passes on to a reversible plate, belt, or scraper conveyer 10 of which the end 10A discharges into a jaw crusher 12, the crushed product then passing via a jigger feeder 13 to a conveyer 14 leading to a grinding plant. When sufficient material has been collected by the separator to make further extraction of steel doubtful, the feed of raw slag to the separator is cut off and, after all the slag on the conveyer has passed to the crusher, the conveyer is reversed. The separator power supply is then cut off and the collected steel is released on to the conveyer 10 which discharges the steel at the end 10B for return to the steel works. Feeding of the slag with the separator in operation is then resumed and the conveyer again made to discharge at the end 10A. The feeder 7, the conveyer 10 and the separator may be push-button controlled by an operator on a platform 15. In the modification shown in Fig. 3, a grading machine 19 of the live-roll grizzly type takes out of the slag stream all smalls of both slag and steel, the oversize slag that passes a separator 18 being discharged into a crusher 20 by a reversible conveyer 21. The material taken out by the grading machine falls on to a belt conveyer 23 discharging on to a conveyer 25 which also receives the crushed material from the crusher 20. The conveyer 25 feeds a secondary crushing plant where further extraction of steel takes place before the slag is crushed to prepare it for grinding.