폐주석산화물로부터 환원공정 및 전해정련을 통한 치과용 고순도 주석 회수

Recovery of Tin with High Purity for Dental Materials from Waste Tin oxide by Reduction and Electro Refining

Abstract

유리생산공정에서 발생하는 요업로 전극봉인 폐주석 산화물로부터 가스환원공정과 전해정련을 통하여 고순도 주석을 회수하기 위한 연구를 수행하였다. 메탄가스 환원공정을 통해 99% 순도의 조주석을 회수하고, 불순물을 미량 제어하였다. 주석의 전해정련시 전류밀도가 $60A/dm^2$이고 전해액의 황산농도가 0.75 mol일 때 99.979%의 고순도 주석이 96.8% 회수되었다. 그리고 전극봉에 포함된 Pb, Sb 등의 독성 불순물 제어가 가능함을 확인하였다.

In this study, using electro-refining process and methane gas reduction, we performed studying the recovery of tin with high purity from waste tin oxide had used as a electrode rod of ceramic furnace which occurred during glass production process. We recovered the crude tin of 99% purity from a methane gas reduction process and controlled a little amount of impurities. When the electrolytic refining condition was a current density of $60A/dm^2$ and the sulfuric acid concentration of 0.75 mol, 96.8% of recovered tin (99.979% of purity) were recovered during the electrolytic refining. We confirmed that toxic impurities such as Pb, Sb included in electrode rod. could be controlled.

Fig. 1. Experimental flow for the recovery of high purity tin from waste tin oxide.

Fig. 2. Sample of Tin Oxide.

Fig. 3. The crude Tin obtained by gas reduction of waste tinoxide.

Fig. 4. Impurity of electro-refined tin with current density(A/m²).

Fig. 5. Pb purity of electro refined of tin with sulfuric acid concentration.

Fig. 6. Sb purity of electro refined of tin by current density and sulfuric acid concentration.

Table 1. The components of waste Tin oxide

Table 2. The condition of electro refining of Tin

Table 3. The component of refined crude Tin

Table 4. Amounts of Tin reduction and purity of electrolytic Tin

Table 5. The Electrochemical series of elements

Table 6. The purity of electrolytic Tin