銅轉爐슬래그에서 亞鉛을 回收함과 同時에 製鐵用原料를 얻기 위하여 鹽化劑로서 鹽化칼슘(CaCl₂·2H₂O)과 鹽化第2鐵(FeCl₃·6H₂O)을, 添加劑로서 窒酸칼슘[Ca(NO₃)₂·4H₂O]과 炭酸칼슘(CaCO₃)을 써서 鹽化揮發實驗을 하였다.
脫亞鉛에 미치는 乾燥와 焙燒의 溫度와 時間, 鹽化劑와 添加劑의 量의 影響들에 대해서 實驗考察하였다. 그리고 脫銅에 대한 結果도 比較하기 위하여 添記하였다.
結果를 要約하면 다음과 같다.
(1) 焙燒溫度는 1100℃가 가장 適合하였고, 時間은 1時間이면 充分했고, 鹽化칼슘 (CaCl₂·2H₂O)의 添加量은 슬래그의 23.37%가 가장 좋았다.
(2) 鹽化第2鐵(FeCl₃·6H₂O)은 鹽化效果가 좋지 못했고, 鹽化칼슘에 窒酸칼슘[Ca(NO₃)₂·4H₂O]을 섞어 쓴것이 매우 좋은 結果를 냈고, 炭酸칼슘의 混用은 鹽化칼슘單味보다 效果가 좋았다.
(3) 燒滓의 燒結强度는 1100℃에서 焙燒한것이 相當히 크나, 1200℃의 것은 매우 굳었다. 脫銅이 脫亞鉛보다 더 잘 되었다.
燒滓中의 Zn, Cu의 殘留量은 각각 0.03, 0.01%까지 낮출 수 있었다.
In order to recover zinc and obtain a suitable raw material for iron smelting from the copper converter slag, chloridizing volatilizition experiment has been performed using calcium chloride (CaCl₂·2H₂O) and ferric chloride (FeCl₃·6H₂O) as chloridizing agents, and calcium nitrate [Ca(NO₃)₂·4H₂O] and calcium carbonate (CaCO₃) as additives. The effects of the temperatures and times of drying and roasting, and the amounts of chloridizing agents as well as the additives on the removal of zinc from the slag have been tested and discussed experimentally and thermodynamically. By the way, the result on the copper was also added for the purpose of the comparison. The results summarized are as follows; (1) The optimum roasting temperature was found to be 1100℃, an hour of roasting time was good enough for the purpose, and the optimum amounts of calcium chloride (CaCl₂·2H₂O) was 23.37pct. (2) Ferric chloride (FeCl₃·6H₂O) as a chloridizing agent was found to be not effective, the addition of calcium nitrate [Ca(NO₃)₂·4H₂O] together with calcium chloride to the slag was shown the best result, and the addition of calcium carbonate (CaCO₃) to calcium chloride was more effective than calcium chloride only. (3) The slag roasted at 1200℃ was considerably harder than that of 1100℃, and copper was more readily removed from the slag than zinc. Under the optimum conditions, 1.77 pct of zinc in the slag was reduced to 0.03 pct, while 5.43 pct of copper to 0.01 pct.