Titanium carbide (TiC) powders are successfully synthesized by carburization of titanium hydride (TiH2) powders. The TiH2 powders with size lower than 45 μm (-325 Mesh) are optimally produced by the hydrogenation process, and are mixed with graphite powder by ball milling. The mixtures are then heat-treated in an Ar atmosphere at 800-1200oC for carburization to occur. It has been experimentally and thermodynamically determined that the dehydrogenation, “TiH2 = Ti + H2”, and carburization, “Ti + C = TiC”, occur simultaneously over the reaction temperature range. The unreacted graphite content (free carbon) in each product is precisely measured by acid dissolution and by the filtering method, and it is possible to conclude that the maximal carbon stoichiometry of TiC0.94 is accomplished at 1200oC.
The study on the fabrication of iron powder from forging scales using hydrogen gas has been conducted on the effect of hydrogen partial pressure, temperature, and reactive time. The mechanism for the reduction of iron oxides was proposed with various steps, and it was found that reduction pattern might be different depending on tem- perature. The iron content in the scale and reduction ratio of oxygen were both increased with increasing reactive time at 0.1atm of hydrogen partial pressure. On the other hand, for over 30 minutes at 0.5 atm of hydrogen partial pressure, the values were found to be almost same. In the long run, iron metallic powder was obtained with over 90% of iron content and an average size of its powder was observed to be about 100 µm.
The extraction of metallic pure vanadium powder from raw oxide has been tried by Mg-reduction. In first stage, powders as initial raw material was reduced by hydrogen gas into phase. powder was reduced in next stage by magnesium gas at 1,073K for 24 hours. After reduction reaction, the MgO component mixed with reduced vanadium powder were dissolved and removed fully in 10% HCl solution for 5 hours at room temperature. The oxygen content and particle size of finally produced vanadium powders were 0.84 wt% and 1 , respectively
본 연구에서는 혼합폐전지로부터 자력선별을 통하여 분류된 자성물질을 약산으로 침출하여 비자성 물질을 용해시키고 니켈과 철을 회수하고자 하였다. 실험은 망간-알칼라인 폐전지와 니켈수소폐전지를 2 : 1의 질량비로 혼합하여 안정적 열처리, 파・분쇄 공정 후 3.2 mm 기준입도로 분리를 한 시료를 800, 1000, 1400 Gauss를 기준으로 자력선별을 수행하였다. 자력선별 실험 결과 1000 Gauss의 자력에서 기존 시료 중 97 wt.% Ni, 98 wt.% Fe, 97 wt.% Co, 11.5 wt.% Mn, 10.5 wt.% Zn가 자성체로 회수되었다. 이 자성체 시료를 pH 0, 0.5, 1, 1.5, 2로 조절한 황산 희석용액으로 침출하여 자성체 내에 Ni과 Fe를 제외한 나머지 금속을 용해시키고자하였다. 침출 실험 결과 pH 0.5 황산 희석용액을 활용한 침출에서 Co, Zn, Mn이 99% 이상 용해되었으며 최종 잔사에는 22.4% Fe와 21.4% Ni만 남아있었다.