Manufacture of Formed Coke by Hot-Briquetting Method (V)

Abstract

By using the pilot plant reported previously with a double roll press in stead of a rotary table type briquette machine, the green briquettes were made from various kinds of coal including foreign coal. In order to obtain an adequate condition for heating the green briquettes by hot sand, many tests were carried out for the green briquettes heating by an electric furnace. Moreover, the green briquettes were heated by mixing with hot sand. The coefficient of contraction for the green briquettes after pre-heating was measured in order to see the effect of pre-heating. The properties of green briquettes and of the formed cokes were described and some explanation for the results also given in this paper. Main results obtained are as follows.(1) Non-caking coal and caking coal were heated separately in two fluidized bed retorts at about 550-600°C and about 200-250°C, respectively. After mixing and forming them the properties of green briquettes are volatile matter 15-25%, apparent density 1. 15-1. 30, trommel index 80-90%.(2) The Formed cokes were obtained by heating the green briquettes using the electric furnace with slowly raising up temperature (3-5°C/min), or putting them into the electric furnace (650-750°C) for about 1. 5-2 hours and moreover another electric furnace at 900°C for abont 40 minutes. The properties of the formed cokes are apparent density 1. 15-1. 40, drum index 90-94.(3) The adequate conditions for heating the green briquettes by hot sand were deduced about the factors of hot sand such as the temperature, the quantity and so on.