Haruhiko Asao

Use of Alternative Fuel at Onahama

Since 1965, a green-charged reverberatory furnace has been operating at Onahama Smelting and Refining Co., Ltd., Fukushima-Ken, Japan. Oil consumption has decreased steadily with increased through-put by use of combustion air preheating, an oxygen-fuel burner, and a computerized ore-blending calculation technique. Increasing oil prices, however, have caused Onahama to introduce alternative fuels, such as coal and waste tires. About 46,000 metric tons/month of copper concentrate was smelted using 3,000 metric ton/month waste tires through October 1979 and 8,500 metric ton/month coal through September 1980. At present, oil consumption is reduced to 2,000 kl/month. Problems, such as incomplete combustion of waste tires, have almost been resolved; potential problems with dust in the waste heat boilers as a result of pulverized coal burning have not been severe. Concentrate is charged in relation to the combustion process under automatic computer control. This paper describes the process of reverberatory furnace operation with alternative fuels at Onahama Smelting and Refining Co. and some advantages and disadvantages resulting from the use of alternative fuels.