Liping Niu

Preparation of CuCr alloys by thermit-reduction electromagnetic stirring

The influences of the additive CaF2, different molds, mold pre-heating temperature, electromagnetic stirring, and alloying elements on CuCr have been investigated respectively during the preparation of CuCr alloys by thermit-reduction electromagnetic stirring. The results indicate that the reasonable reactant mass ratio of CuO: Cr2O3: Al is 100:140:160; CaF2 can reduce the solidification point of slags to improve the metal separating efficiency from slags; the crystal particles become thinner because of the high cooling velocity in the metal mold; while casting in the graphite mold, the casting properties of CuCr improve with the increase of pre-heating temperature; the compact alloys are prepared at 500°C; electromagnetic stirring can prevent the growth of dendrite crystal into refine crystal particles, as well as homogenize Cu and Cr to improve the CuCr properties: the optimal stirring time is 7 min; when the alloying elements Ni and Co are added to the reactants, elements Cu and Cr can distribute evenly but the crystal particles become thick.

Desulfurization of Copper-Iron Reduced from Copper Slag

In order to maximize the use of copper slag, a new idea that copper slag is reduced to smelt copper-containing antimicrobial stainless steel was proposed. But copper-iron reduced from copper slag contains a large number of copper matte, making sulfur content high. In this article, desulfurization of copper-iron was studied. The Fact-Sage software was used to calculate ΔG of the desulfurization reaction. Calcium oxide, calcium carbide and ferromanganese were used as desulfurization agent. The results show that desulfurization capacity of calcium oxide is poor, but with addition of carbon, desulfurization effect of calcium oxide will be enhanced. Calcium carbide and ferromanganese have good desulfurization effect.

Study on the Direct Oxidation Thermal Decomposition of Magnesium Chloride by Product in the Sponge Titanium Production Process to Prepare Magnesium Oxide

Molten MgCl2 generally sold as a kind of waste at low price after cooling, which caused the waste of resource and energy. In order to solve the problem, a new method named “situ pyrolysis of molten magnesium chloride” was proposed. The molten MgCl2 produced by vacuum distillation in magnesium thermal reduction process was treated by the direct oxidation thermal decomposition method to produce super fine MgO with high purity. The magnesium produced by thermal reduction of MgO could be returned to the boiling chlorination of high titanium slag. The new cycle of magnesium and chloride in titanium sponge production was achieved. Based on the thermodynamic analysis of the reaction between O2 and MgCl2, the single factor experiments had been done. The optimal reaction condition was determined and the impact of each factor in the pyrolysis process was studied.