A selective chlorination process using magnesium chloride (MgCl₂) as chlorinating agent was investigated with the aim of developing a process for removing iron directly from ilmenite, which is a low-grade titanium ore known as FeTiO₃. Two crucibles, one consisting of titanium ore and the other consisting of a mixture of titanium ore and MgCl₂, were placed in a gas-tight quartz tube, and then both crucibles were heated to 1000 K. In some experiments, H₂O vapor was introduced in the quartz tube. HCl gas produced from the MgCl₂/titanium ore mixture reacted with the iron present in the titanium ore placed in the other crucible to produce TiO₂. Iron present in the titanium ore of the titanium ore/MgCl₂ mixture reacted with MgCl₂, and MgTiO₃ and MgO were obtained. Iron in the titanium ore present in both crucibles was removed as FeCl₂ (l,g). In these experiments, the effects of the particle size of the titanium ore and the atmosphere on selective chlorination were investigated. In addition, titanium ores produced in Vietnam, Australia and China were used as feedstocks. By the chlorination process, 97% TiO₂ was obtained directly in one step from the low-grade titanium ore containing 51% TiO₂ under certain conditions, thus demonstrating the feasibility of the selective chlorination process for producing high-purity titanium dioxide from low-grade titanium ore.