Study Of Hot Galvanized Slag Recycling Technology

Iron and steel is a metal material which has the maximum output and wildest application, but its most prominent weakness is that it will be corroded by wet air in low temperature. In recent few years, this problem is more and more serious because the environment pollution is deteriorated gradually as the development of industrialization. Hot-galvanizing is the most fundamental, most wild-used and most effective method of protecting iron and steel from being corroded all over the world. Galvanizing industry is the biggest consumption field of zinc, and its consumption takes up40%of the total zinc consumption. The quantity of dross grows sharply as the galvanizing industry develops rapidly. The total output of dross in our country is100,000ton annually. Hot-galvanizing dross is a zinc regeneration resource of very high zinc content, and the recycling of dross also can extent the service life of zinc resource, as well as reduce product energy consumption, decrease environment pollution and increase social and economic benifits. But there is no mature processes engineering to recycle hot-galvanizing dross except for some low efficiency ones in our country.This article takes over the mature technology about tower-type zinc refining furnace in dealing with crude zinc, together with dry residue distillation furnace, proposes an high efficient recycling process for hot-galvanizing dross, and proceeds the design calculation of the main equipments. Because the shortage of low efficiency of traditional heat exchanger, high temperature of waste gas and large floor area, the mature heat accumulating type combustion technology is applied to the tower-type zinc refining furnace, for the purpose of recycling the afterheat of waste gas in most ultimate, reducing the waste gas temperature, improving the furnace heat efficiency and cutting down fuel combustion.Specific to the new process scheme, on the base of design, commercial software of FLUENT is applied to proceed numerical simulation and comparison about tower-type zinc refining furnace in the conditions of with and without heat accumulating type combustion technology, including the temperature field in the combustion chamber and the emission of NOx, and the results prove the heat accumulating technology has a steadier and more homogeneous temperature field distribution which meets the need of process. It is convinced that the high efficient recycling of hot galvanizing dross technology is feasible and the solution which is put forward is superior in quality and recovery rate.this will produce tremendous economic and social benefits, can produce largely.